From 8e2744b8453ffa4e3b6c0a398d17996f9b499c42 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Sun, 11 Jun 2023 17:09:22 +0200
Subject: [PATCH 01/18] more build tools

---
 crates/re_build_tools/src/hashing.rs | 48 +++++++---------------------
 1 file changed, 11 insertions(+), 37 deletions(-)

diff --git a/crates/re_build_tools/src/hashing.rs b/crates/re_build_tools/src/hashing.rs
index f734651b8fa4..c8a37035ce03 100644
--- a/crates/re_build_tools/src/hashing.rs
+++ b/crates/re_build_tools/src/hashing.rs
@@ -5,8 +5,6 @@ use std::{fs, io};
 use anyhow::Context as _;
 use sha2::{Digest, Sha256};
 
-use crate::{rerun_if_changed, rerun_if_changed_or_doesnt_exist};
-
 // ---
 
 fn encode_hex(bytes: &[u8]) -> String {
@@ -19,8 +17,8 @@ fn encode_hex(bytes: &[u8]) -> String {
 
 /// Walks the directory at `path` in filename order.
 ///
-/// If `extensions` is specified, only files with the right extensions will be iterated.
-/// Specified extensions should _not_ include the leading dot, e.g. `fbs` rather than `.fbs`.
+/// If `extensions` is specified, only files with the right extensions will be hashed.
+/// Specified extensions should include the dot, e.g. `.fbs`.
 pub fn iter_dir<'a>(
     path: impl AsRef<Path>,
     extensions: Option<&'a [&'a str]>,
@@ -30,9 +28,9 @@ pub fn iter_dir<'a>(
         let is_interesting = extensions.map_or(true, |extensions| {
             extensions.iter().any(|ext| {
                 entry
-                    .path()
-                    .extension()
-                    .map_or(false, |ext2| *ext == ext2.to_string_lossy())
+                    .file_name()
+                    .to_str()
+                    .map_or(false, |s| s.ends_with(ext))
             })
         });
         is_dir || is_interesting
@@ -50,8 +48,6 @@ pub fn iter_dir<'a>(
 /// Given a file path, computes the sha256 hash of its contents and returns an hexadecimal string
 /// for it.
 ///
-/// This will automatically emit a `rerun-if-changed` clause for the specified file.
-///
 /// Panics if the file doesn't exist.
 pub fn compute_file_hash(path: impl AsRef<Path>) -> String {
     let mut hasher = Sha256::new();
@@ -64,20 +60,14 @@ pub fn compute_file_hash(path: impl AsRef<Path>) -> String {
         .with_context(|| format!("couldn't copy from {path:?}"))
         .unwrap();
 
-    rerun_if_changed(path);
-
     encode_hex(hasher.finalize().as_slice())
 }
 
-/// Given a directory path, computes the sha256 hash of the accumulated contents of all of its
-/// files (ordered by filename), and returns an hexadecimal string for it.
-///
-/// This includes files in sub-directories (i.e. it's recursive).
-///
-/// This will automatically emit a `rerun-if-changed` clause for all the files that were hashed.
+/// Given a directory path, computes the sha256 hash of its contents (ordered by filename) and
+/// returns an hexadecimal string for it.
 ///
-/// If `extensions` is specified, only files with the right extensions will be iterated.
-/// Specified extensions should _not_ include the leading dot, e.g. `fbs` rather than `.fbs`.
+/// If `extensions` is specified, only files with the right extensions will be hashed.
+/// Specified extensions should include the dot, e.g. `.fbs`.
 pub fn compute_dir_hash<'a>(path: impl AsRef<Path>, extensions: Option<&'a [&'a str]>) -> String {
     let mut hasher = Sha256::new();
 
@@ -89,19 +79,13 @@ pub fn compute_dir_hash<'a>(path: impl AsRef<Path>, extensions: Option<&'a [&'a
         io::copy(&mut file, &mut hasher)
             .with_context(|| format!("couldn't copy from {filepath:?}"))
             .unwrap();
-
-        rerun_if_changed(path);
     }
 
     encode_hex(hasher.finalize().as_slice())
 }
 
-/// Given a crate name, computes the sha256 hash of its source code (ordered by filename) and
+/// Given a crate name, computes the sha256 hash of its source (ordered by filename) and
 /// returns an hexadecimal string for it.
-///
-/// This includes the source code of all its direct and indirect dependencies.
-///
-/// This will automatically emit a `rerun-if-changed` clause for all the files that were hashed.
 pub fn compute_crate_hash(pkg_name: impl AsRef<str>) -> String {
     use cargo_metadata::{CargoOpt, MetadataCommand};
     let metadata = MetadataCommand::new()
@@ -138,9 +122,6 @@ pub fn compute_strings_hash(strs: &[&str]) -> String {
 
 /// Writes the given `hash` at the specified `path`.
 ///
-/// `hash` should have been computed using of the methods in this module: [`compute_file_hash`],
-/// [`compute_dir_hash`], [`compute_crate_hash`].
-///
 /// Panics on I/O errors.
 ///
 /// Use [`read_versioning_hash`] to read it back.
@@ -156,23 +137,16 @@ pub fn write_versioning_hash(path: impl AsRef<Path>, hash: impl AsRef<str>) {
         {hash}
         "
     ));
-    std::fs::write(path, contents.trim())
+    std::fs::write(path, contents)
         .with_context(|| format!("couldn't write to {path:?}"))
         .unwrap();
 }
 
 /// Reads back a versioning hash that was written with [`write_versioning_hash`].
 ///
-/// This will automatically emit a `rerun-if-changed` clause for the specified filepath.
-///
 /// Returns `None` on error.
 pub fn read_versioning_hash(path: impl AsRef<Path>) -> Option<String> {
     let path = path.as_ref();
-
-    // NOTE: It's important we trigger if the file doesn't exist, as this means the user explicitly
-    // deleted the versioning file, i.e. they're trying to force a rebuild.
-    rerun_if_changed_or_doesnt_exist(path);
-
     std::fs::read_to_string(path).ok().and_then(|contents| {
         contents
             .lines()

From 326c1951d1760e3c43370c730b1d5d08f1bacb23 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Sun, 11 Jun 2023 17:31:40 +0200
Subject: [PATCH 02/18] self-review

---
 crates/re_build_tools/src/hashing.rs | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/crates/re_build_tools/src/hashing.rs b/crates/re_build_tools/src/hashing.rs
index c8a37035ce03..1c9f8fd5aed3 100644
--- a/crates/re_build_tools/src/hashing.rs
+++ b/crates/re_build_tools/src/hashing.rs
@@ -17,7 +17,7 @@ fn encode_hex(bytes: &[u8]) -> String {
 
 /// Walks the directory at `path` in filename order.
 ///
-/// If `extensions` is specified, only files with the right extensions will be hashed.
+/// If `extensions` is specified, only files with the right extensions will be iterated.
 /// Specified extensions should include the dot, e.g. `.fbs`.
 pub fn iter_dir<'a>(
     path: impl AsRef<Path>,
@@ -63,8 +63,10 @@ pub fn compute_file_hash(path: impl AsRef<Path>) -> String {
     encode_hex(hasher.finalize().as_slice())
 }
 
-/// Given a directory path, computes the sha256 hash of its contents (ordered by filename) and
-/// returns an hexadecimal string for it.
+/// Given a directory path, computes the sha256 hash of the accumulated contents of all of its
+/// files (ordered by filename), and returns an hexadecimal string for it.
+///
+/// This includes files in sub-directories (i.e. it's recursive).
 ///
 /// If `extensions` is specified, only files with the right extensions will be hashed.
 /// Specified extensions should include the dot, e.g. `.fbs`.
@@ -84,8 +86,10 @@ pub fn compute_dir_hash<'a>(path: impl AsRef<Path>, extensions: Option<&'a [&'a
     encode_hex(hasher.finalize().as_slice())
 }
 
-/// Given a crate name, computes the sha256 hash of its source (ordered by filename) and
+/// Given a crate name, computes the sha256 hash of its source code (ordered by filename) and
 /// returns an hexadecimal string for it.
+///
+/// This includes the source code of all its direct and indirect dependencies.
 pub fn compute_crate_hash(pkg_name: impl AsRef<str>) -> String {
     use cargo_metadata::{CargoOpt, MetadataCommand};
     let metadata = MetadataCommand::new()
@@ -137,7 +141,7 @@ pub fn write_versioning_hash(path: impl AsRef<Path>, hash: impl AsRef<str>) {
         {hash}
         "
     ));
-    std::fs::write(path, contents)
+    std::fs::write(path, contents.trim())
         .with_context(|| format!("couldn't write to {path:?}"))
         .unwrap();
 }

From 40f40594da44722754773bef14fb6985a15fc5db Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Tue, 13 Jun 2023 08:57:06 +0200
Subject: [PATCH 03/18] addressing PR comments

---
 crates/re_build_tools/src/hashing.rs | 34 +++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/crates/re_build_tools/src/hashing.rs b/crates/re_build_tools/src/hashing.rs
index 1c9f8fd5aed3..f734651b8fa4 100644
--- a/crates/re_build_tools/src/hashing.rs
+++ b/crates/re_build_tools/src/hashing.rs
@@ -5,6 +5,8 @@ use std::{fs, io};
 use anyhow::Context as _;
 use sha2::{Digest, Sha256};
 
+use crate::{rerun_if_changed, rerun_if_changed_or_doesnt_exist};
+
 // ---
 
 fn encode_hex(bytes: &[u8]) -> String {
@@ -18,7 +20,7 @@ fn encode_hex(bytes: &[u8]) -> String {
 /// Walks the directory at `path` in filename order.
 ///
 /// If `extensions` is specified, only files with the right extensions will be iterated.
-/// Specified extensions should include the dot, e.g. `.fbs`.
+/// Specified extensions should _not_ include the leading dot, e.g. `fbs` rather than `.fbs`.
 pub fn iter_dir<'a>(
     path: impl AsRef<Path>,
     extensions: Option<&'a [&'a str]>,
@@ -28,9 +30,9 @@ pub fn iter_dir<'a>(
         let is_interesting = extensions.map_or(true, |extensions| {
             extensions.iter().any(|ext| {
                 entry
-                    .file_name()
-                    .to_str()
-                    .map_or(false, |s| s.ends_with(ext))
+                    .path()
+                    .extension()
+                    .map_or(false, |ext2| *ext == ext2.to_string_lossy())
             })
         });
         is_dir || is_interesting
@@ -48,6 +50,8 @@ pub fn iter_dir<'a>(
 /// Given a file path, computes the sha256 hash of its contents and returns an hexadecimal string
 /// for it.
 ///
+/// This will automatically emit a `rerun-if-changed` clause for the specified file.
+///
 /// Panics if the file doesn't exist.
 pub fn compute_file_hash(path: impl AsRef<Path>) -> String {
     let mut hasher = Sha256::new();
@@ -60,6 +64,8 @@ pub fn compute_file_hash(path: impl AsRef<Path>) -> String {
         .with_context(|| format!("couldn't copy from {path:?}"))
         .unwrap();
 
+    rerun_if_changed(path);
+
     encode_hex(hasher.finalize().as_slice())
 }
 
@@ -68,8 +74,10 @@ pub fn compute_file_hash(path: impl AsRef<Path>) -> String {
 ///
 /// This includes files in sub-directories (i.e. it's recursive).
 ///
-/// If `extensions` is specified, only files with the right extensions will be hashed.
-/// Specified extensions should include the dot, e.g. `.fbs`.
+/// This will automatically emit a `rerun-if-changed` clause for all the files that were hashed.
+///
+/// If `extensions` is specified, only files with the right extensions will be iterated.
+/// Specified extensions should _not_ include the leading dot, e.g. `fbs` rather than `.fbs`.
 pub fn compute_dir_hash<'a>(path: impl AsRef<Path>, extensions: Option<&'a [&'a str]>) -> String {
     let mut hasher = Sha256::new();
 
@@ -81,6 +89,8 @@ pub fn compute_dir_hash<'a>(path: impl AsRef<Path>, extensions: Option<&'a [&'a
         io::copy(&mut file, &mut hasher)
             .with_context(|| format!("couldn't copy from {filepath:?}"))
             .unwrap();
+
+        rerun_if_changed(path);
     }
 
     encode_hex(hasher.finalize().as_slice())
@@ -90,6 +100,8 @@ pub fn compute_dir_hash<'a>(path: impl AsRef<Path>, extensions: Option<&'a [&'a
 /// returns an hexadecimal string for it.
 ///
 /// This includes the source code of all its direct and indirect dependencies.
+///
+/// This will automatically emit a `rerun-if-changed` clause for all the files that were hashed.
 pub fn compute_crate_hash(pkg_name: impl AsRef<str>) -> String {
     use cargo_metadata::{CargoOpt, MetadataCommand};
     let metadata = MetadataCommand::new()
@@ -126,6 +138,9 @@ pub fn compute_strings_hash(strs: &[&str]) -> String {
 
 /// Writes the given `hash` at the specified `path`.
 ///
+/// `hash` should have been computed using of the methods in this module: [`compute_file_hash`],
+/// [`compute_dir_hash`], [`compute_crate_hash`].
+///
 /// Panics on I/O errors.
 ///
 /// Use [`read_versioning_hash`] to read it back.
@@ -148,9 +163,16 @@ pub fn write_versioning_hash(path: impl AsRef<Path>, hash: impl AsRef<str>) {
 
 /// Reads back a versioning hash that was written with [`write_versioning_hash`].
 ///
+/// This will automatically emit a `rerun-if-changed` clause for the specified filepath.
+///
 /// Returns `None` on error.
 pub fn read_versioning_hash(path: impl AsRef<Path>) -> Option<String> {
     let path = path.as_ref();
+
+    // NOTE: It's important we trigger if the file doesn't exist, as this means the user explicitly
+    // deleted the versioning file, i.e. they're trying to force a rebuild.
+    rerun_if_changed_or_doesnt_exist(path);
+
     std::fs::read_to_string(path).ok().and_then(|contents| {
         contents
             .lines()

From 0a7f4451dbccffb3166a0e3b22fe85d225e1d1b0 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Sun, 11 Jun 2023 17:44:22 +0200
Subject: [PATCH 04/18] introduce re_types_builder

---
 Cargo.lock                                    |  29 +-
 crates/re_types_builder/Cargo.toml            |   2 +-
 crates/re_types_builder/build.rs              |  20 +-
 .../definitions/reflection.fbs                |   3 -
 crates/re_types_builder/src/arrow_registry.rs |  14 +-
 crates/re_types_builder/src/codegen/common.rs |  19 --
 crates/re_types_builder/src/codegen/mod.rs    |   7 +-
 crates/re_types_builder/src/codegen/python.rs | 322 +++++++++---------
 crates/re_types_builder/src/codegen/rust.rs   | 157 +++++----
 crates/re_types_builder/src/lib.rs            | 104 +++---
 crates/re_types_builder/src/objects.rs        | 146 ++++----
 11 files changed, 411 insertions(+), 412 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 1558ece32be5..be455137ee2a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3729,7 +3729,7 @@ dependencies = [
  "pyo3-build-config",
  "pyo3-ffi",
  "pyo3-macros",
- "unindent",
+ "unindent 0.1.11",
 ]
 
 [[package]]
@@ -3938,7 +3938,7 @@ dependencies = [
  "glob",
  "sha2",
  "time",
- "unindent",
+ "unindent 0.1.11",
  "walkdir",
 ]
 
@@ -4227,7 +4227,7 @@ dependencies = [
  "thiserror",
  "tobj",
  "type-map",
- "unindent",
+ "unindent 0.2.1",
  "walkdir",
  "wasm-bindgen-futures",
  "web-sys",
@@ -4507,7 +4507,7 @@ dependencies = [
  "flatbuffers",
  "indent",
  "re_build_tools",
- "unindent",
+ "unindent 0.2.1",
  "xshell",
 ]
 
@@ -5801,6 +5801,12 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e1766d682d402817b5ac4490b3c3002d91dfa0d22812f341609f97b08757359c"
 
+[[package]]
+name = "unindent"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aa30f5ea51ff7edfc797c6d3f9ec8cbd8cfedef5371766b7181d33977f4814f"
+
 [[package]]
 name = "untrusted"
 version = "0.7.1"
@@ -6665,6 +6671,21 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1dbabb1cbd15a1d6d12d9ed6b35cc6777d4af87ab3ba155ea37215f20beab80c"
 
+[[package]]
+name = "xshell"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "962c039b3a7b16cf4e9a4248397c6585c07547412e7d6a6e035389a802dcfe90"
+dependencies = [
+ "xshell-macros",
+]
+
+[[package]]
+name = "xshell-macros"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1dbabb1cbd15a1d6d12d9ed6b35cc6777d4af87ab3ba155ea37215f20beab80c"
+
 [[package]]
 name = "xxhash-rust"
 version = "0.8.6"
diff --git a/crates/re_types_builder/Cargo.toml b/crates/re_types_builder/Cargo.toml
index ffdd334219bd..01b3cc8efc4a 100644
--- a/crates/re_types_builder/Cargo.toml
+++ b/crates/re_types_builder/Cargo.toml
@@ -25,7 +25,7 @@ arrow2.workspace = true
 convert_case = "0.6"
 flatbuffers = "23.0"
 indent = "0.1"
-unindent.workspace = true
+unindent = "0.2"
 xshell = "0.2"
 
 
diff --git a/crates/re_types_builder/build.rs b/crates/re_types_builder/build.rs
index bac5e2d4deb6..199ee8e2a8bb 100644
--- a/crates/re_types_builder/build.rs
+++ b/crates/re_types_builder/build.rs
@@ -3,7 +3,8 @@
 use xshell::{cmd, Shell};
 
 use re_build_tools::{
-    compute_file_hash, is_tracked_env_var_set, read_versioning_hash, write_versioning_hash,
+    compute_file_hash, is_tracked_env_var_set, read_versioning_hash, rerun_if_changed,
+    rerun_if_changed_or_doesnt_exist, write_versioning_hash,
 };
 
 // ---
@@ -32,14 +33,9 @@ fn main() {
         return;
     }
 
-    // We're building an actual build graph here, and Cargo has no idea about it.
-    //
-    // Worse: some nodes in our build graph actually output artifacts into the src/ directory,
-    // which Cargo always interprets as "need to rebuild everything ASAP", leading to an infinite
-    // feedback loop.
-    //
-    // For these reasons, we manually compute and track signature hashes for the graph nodes we
-    // depend on, and make sure to exit early if everything's already up to date.
+    rerun_if_changed_or_doesnt_exist(SOURCE_HASH_PATH);
+    rerun_if_changed(FBS_REFLECTION_DEFINITION_PATH);
+
     let cur_hash = read_versioning_hash(SOURCE_HASH_PATH);
     let new_hash = compute_file_hash(FBS_REFLECTION_DEFINITION_PATH);
 
@@ -54,8 +50,6 @@ fn main() {
         }
     }
 
-    // NOTE: This requires `flatc` to be in $PATH, but only for contributors, not end users.
-    // Even for contributors, `flatc` won't be needed unless they edit some of the .fbs files.
     let sh = Shell::new().unwrap();
     cmd!(
         sh,
@@ -66,8 +60,8 @@ fn main() {
 
     // NOTE: We're purposefully ignoring the error here.
     //
-    // In the very unlikely chance that the user doesn't have the `fmt` component installed,
-    // there's still no good reason to fail the build.
+    // In the very unlikely chance that the user doesn't have `rustfmt` in their $PATH, there's
+    // still no good reason to fail the build.
     //
     // The CI will catch the unformatted file at PR time and complain appropriately anyhow.
     cmd!(sh, "cargo fmt").run().ok();
diff --git a/crates/re_types_builder/definitions/reflection.fbs b/crates/re_types_builder/definitions/reflection.fbs
index cf6cb9e3c4e4..513311f1b9c3 100644
--- a/crates/re_types_builder/definitions/reflection.fbs
+++ b/crates/re_types_builder/definitions/reflection.fbs
@@ -1,6 +1,3 @@
-// Copied verbatim from the official flatbuffers source tree:
-// https://github.com/google/flatbuffers/blob/63b7b25289447313ab6e79191fa1733748dca0da/reflection/reflection.fbs
-
 // This schema defines objects that represent a parsed schema, like
 // the binary version of a .fbs file.
 // This could be used to operate on unknown FlatBuffers at runtime.
diff --git a/crates/re_types_builder/src/arrow_registry.rs b/crates/re_types_builder/src/arrow_registry.rs
index 505d0ccd253a..dd07e7fba4d1 100644
--- a/crates/re_types_builder/src/arrow_registry.rs
+++ b/crates/re_types_builder/src/arrow_registry.rs
@@ -4,7 +4,13 @@ use anyhow::Context as _;
 use arrow2::datatypes::{DataType, Field, UnionMode};
 use std::collections::{BTreeMap, HashMap};
 
-use crate::{ElementType, Object, Type, ARROW_ATTR_SPARSE_UNION, ARROW_ATTR_TRANSPARENT};
+use crate::{ElementType, Object, Type};
+
+// ---
+
+// TODO(cmc): find a way to extract attr name constants directly from the IDL definitions
+pub const ARROW_ATTR_TRANSPARENT: &str = "arrow.attr.transparent";
+pub const ARROW_ATTR_SPARSE_UNION: &str = "arrow.attr.sparse_union";
 
 // --- Registry ---
 
@@ -50,11 +56,12 @@ impl ArrowRegistry {
 
     fn arrow_datatype_from_object(&self, obj: &Object) -> LazyDatatype {
         let is_struct = obj.is_struct();
+
         let is_transparent = obj.try_get_attr::<String>(ARROW_ATTR_TRANSPARENT).is_some();
         let num_fields = obj.fields.len();
 
         assert!(
-            !is_transparent || (is_struct && num_fields == 1),
+            !(is_transparent && (!is_struct || num_fields != 1)),
             "cannot have a transparent arrow object with any number of fields but 1: {:?} has {num_fields}",
             obj.fqname,
         );
@@ -163,9 +170,6 @@ impl ArrowRegistry {
 // --- Field ---
 
 /// A yet-to-be-resolved [`arrow2::datatypes::Field`].
-///
-/// Type resolution is a two-pass process as we first need to register all existing types before we
-/// can denormalize their definitions into their parents.
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
 pub struct LazyField {
     /// Its name
diff --git a/crates/re_types_builder/src/codegen/common.rs b/crates/re_types_builder/src/codegen/common.rs
index d0bd52a5716c..4317b76c481c 100644
--- a/crates/re_types_builder/src/codegen/common.rs
+++ b/crates/re_types_builder/src/codegen/common.rs
@@ -39,22 +39,3 @@ pub fn quote_doc_from_docs(docs: &Docs, tags: &[&str]) -> Vec<String> {
 
     lines
 }
-
-pub trait StringExt {
-    fn push_text(&mut self, text: impl AsRef<str>, linefeeds: usize, indent: usize) -> &mut Self;
-    fn push_unindented_text(&mut self, text: impl AsRef<str>, linefeeds: usize) -> &mut Self;
-}
-
-impl StringExt for String {
-    fn push_text(&mut self, text: impl AsRef<str>, linefeeds: usize, indent: usize) -> &mut Self {
-        self.push_str(&indent::indent_all_by(indent, text.as_ref()));
-        self.push_str(&vec!["\n"; linefeeds].join(""));
-        self
-    }
-
-    fn push_unindented_text(&mut self, text: impl AsRef<str>, linefeeds: usize) -> &mut Self {
-        self.push_str(&unindent::unindent(text.as_ref()));
-        self.push_str(&vec!["\n"; linefeeds].join(""));
-        self
-    }
-}
diff --git a/crates/re_types_builder/src/codegen/mod.rs b/crates/re_types_builder/src/codegen/mod.rs
index 240fabd14e9a..49bdc9d9278f 100644
--- a/crates/re_types_builder/src/codegen/mod.rs
+++ b/crates/re_types_builder/src/codegen/mod.rs
@@ -15,10 +15,15 @@ pub trait CodeGenerator {
 pub const AUTOGEN_WARNING: &str =
     "NOTE: This file was autogenerated by re_types_builder; DO NOT EDIT.";
 
+// TODO(cmc): find a way to extract attr name constants directly from the IDL definitions
+pub const RERUN_ATTR_COMPONENT_REQUIRED: &str = "rerun.attr.component_required";
+pub const RERUN_ATTR_COMPONENT_RECOMMENDED: &str = "rerun.attr.component_recommended";
+pub const RERUN_ATTR_COMPONENT_OPTIONAL: &str = "rerun.attr.component_optional";
+
 // ---
 
 mod common;
-use self::common::{quote_doc_from_docs, StringExt};
+use self::common::quote_doc_from_docs;
 
 mod python;
 mod rust;
diff --git a/crates/re_types_builder/src/codegen/python.rs b/crates/re_types_builder/src/codegen/python.rs
index a695cbee5970..9b6f85970405 100644
--- a/crates/re_types_builder/src/codegen/python.rs
+++ b/crates/re_types_builder/src/codegen/python.rs
@@ -8,9 +8,8 @@ use std::{
 };
 
 use crate::{
-    codegen::{StringExt as _, AUTOGEN_WARNING},
-    ArrowRegistry, CodeGenerator, Docs, ElementType, Object, ObjectField, ObjectKind, Objects,
-    Type, PYTHON_ATTR_ALIASES, PYTHON_ATTR_ARRAY_ALIASES, PYTHON_ATTR_TRANSPARENT,
+    codegen::AUTOGEN_WARNING, ArrowRegistry, CodeGenerator, Docs, ElementType, Object, ObjectField,
+    ObjectKind, Objects, Type,
 };
 
 // ---
@@ -18,6 +17,11 @@ use crate::{
 // NOTE: `rerun2` while we figure out how to integrate back into the main SDK.
 const MODULE_NAME: &str = "rerun2";
 
+// TODO(cmc): find a way to extract attr name constants directly from the IDL definitions
+pub const ATTR_TRANSPARENT: &str = "python.attr.transparent";
+pub const ATTR_ALIASES: &str = "python.attr.aliases";
+pub const ATTR_ARRAY_ALIASES: &str = "python.attr.array_aliases";
+
 pub struct PythonCodeGenerator {
     pkg_path: PathBuf,
 }
@@ -90,20 +94,17 @@ fn quote_lib(out_path: impl AsRef<Path>, archetype_names: &[String]) -> PathBuf
         .unwrap();
 
     let path = out_path.join("__init__.py");
-    let manifest = quote_manifest(archetype_names);
     let archetype_names = archetype_names.join(", ");
 
     let mut code = String::new();
 
+    // NOTE: noqa F401 (unused import) because while unnecessary these listings are
+    // very useful to look at.
     code += &unindent::unindent(&format!(
         r#"
         # {AUTOGEN_WARNING}
 
-        from __future__ import annotations
-
-        __all__ = [{manifest}]
-
-        from .archetypes import {archetype_names}
+        from .archetypes import {archetype_names} # noqa: F401
         "#
     ));
 
@@ -135,9 +136,16 @@ fn quote_objects(
         } else {
             QuotedObject::from_union(arrow_registry, all_objects, obj)
         };
-
         let filepath = out_path.join(obj.filepath.file_name().unwrap());
-        files.entry(filepath.clone()).or_default().push(obj);
+
+        match files.entry(filepath.clone()) {
+            std::collections::hash_map::Entry::Occupied(mut entry) => {
+                entry.get_mut().push(obj);
+            }
+            std::collections::hash_map::Entry::Vacant(entry) => {
+                entry.insert(vec![obj]);
+            }
+        };
     }
 
     // (module_name, [object_name])
@@ -147,27 +155,25 @@ fn quote_objects(
     for (filepath, objs) in files {
         let names = objs
             .iter()
-            .flat_map(|obj| match obj.kind {
+            .map(|obj| match obj.kind {
                 ObjectKind::Datatype | ObjectKind::Component => {
                     let name = &obj.name;
-
-                    vec![
-                        format!("{name}"),
-                        format!("{name}Like"),
-                        format!("{name}Array"),
-                        format!("{name}ArrayLike"),
-                        format!("{name}Type"),
-                    ]
+                    format!("{name}, {name}Like, {name}Array, {name}ArrayLike, {name}Type")
                 }
-                ObjectKind::Archetype => vec![obj.name.clone()],
+                ObjectKind::Archetype => obj.name.clone(),
             })
             .collect::<Vec<_>>();
 
         // NOTE: Isolating the file stem only works because we're handling datatypes, components
         // and archetypes separately (and even then it's a bit shady, eh).
-        mods.entry(filepath.file_stem().unwrap().to_string_lossy().to_string())
-            .or_default()
-            .extend(names.iter().cloned());
+        match mods.entry(filepath.file_stem().unwrap().to_string_lossy().to_string()) {
+            std::collections::hash_map::Entry::Occupied(mut entry) => {
+                entry.get_mut().extend(names);
+            }
+            std::collections::hash_map::Entry::Vacant(entry) => {
+                entry.insert(names);
+            }
+        };
 
         filepaths.push(filepath.clone());
         let mut file = std::fs::File::create(&filepath)
@@ -175,23 +181,11 @@ fn quote_objects(
             .unwrap();
 
         let mut code = String::new();
-        code.push_text(&format!("# {AUTOGEN_WARNING}"), 2, 0);
-
-        let manifest = quote_manifest(names);
-        code.push_unindented_text(
-            format!(
-                "
-                from __future__ import annotations
-
-                __all__ = [{manifest}]
-
-                ",
-            ),
-            0,
-        );
+        code.push_str(&format!("# {AUTOGEN_WARNING}\n\n"));
 
         for obj in objs {
-            code.push_text(&obj.code, 1, 0);
+            code.push_str(&obj.code);
+            code.push('\n');
         }
         file.write_all(code.as_bytes())
             .with_context(|| format!("{filepath:?}"))
@@ -204,25 +198,20 @@ fn quote_objects(
 
         let mut code = String::new();
 
-        let manifest = quote_manifest(mods.iter().flat_map(|(_, names)| names.iter()));
-
-        code.push_text(&format!("# {AUTOGEN_WARNING}"), 2, 0);
-        code.push_unindented_text(
-            format!(
-                "
-                from __future__ import annotations
+        code.push_str(&format!("# {AUTOGEN_WARNING}\n\n"));
+        code.push_str(&unindent::unindent(
+            "
+            # NOTE:
+            # - we use fully qualified paths to prevent lazy circular imports
+            # - `noqa F401` (unused import) everywhere because, while not strictly necessary,
+            #   these imports are very nice for end users.
 
-                __all__ = [{manifest}]
-
-                # NOTE: we use fully qualified paths to prevent lazy circular imports.
-                ",
-            ),
-            0,
-        );
+            ",
+        ));
 
         for (module, names) in &mods {
             let names = names.join(", ");
-            code.push_text(&format!("from .{module} import {names}"), 1, 0);
+            code.push_str(&format!("from .{module} import {names} # noqa: F401\n"));
         }
 
         filepaths.push(path.clone());
@@ -262,28 +251,26 @@ impl QuotedObject {
 
         let mut code = String::new();
 
-        code.push_text(&quote_module_prelude(), 0, 0);
+        code.push_str(&quote_module_prelude());
 
         for clause in obj
             .fields
             .iter()
             .filter_map(quote_import_clauses_from_field)
         {
-            code.push_text(&clause, 1, 0);
+            code.push_str(&clause);
+            code.push('\n');
         }
 
-        code.push_unindented_text(
-            format!(
-                r#"
+        code.push_str(&unindent::unindent(&format!(
+            r#"
 
-                @dataclass
-                class {name}:
-                "#
-            ),
-            0,
-        );
+            @dataclass
+            class {name}:
+            "#
+        )));
 
-        code.push_text(quote_doc_from_docs(docs), 0, 4);
+        code.push_str(&indent::indent_all_by(4, quote_doc_from_docs(docs)));
 
         for field in fields {
             let ObjectField {
@@ -308,25 +295,42 @@ impl QuotedObject {
             let typ = if field.required {
                 typ
             } else {
-                format!("{typ} | None = None")
+                format!("Optional[{typ}] = None")
             };
 
-            code.push_text(format!("{name}: {typ}"), 1, 4);
+            code.push_str(&indent::indent_all_by(4, format!("{name}: {typ}\n")));
 
-            code.push_text(quote_doc_from_docs(docs), 0, 4);
+            code.push_str(&indent::indent_all_by(4, quote_doc_from_docs(docs)));
         }
 
-        code.push_text(quote_str_repr_from_obj(obj), 1, 4);
-        code.push_text(quote_array_method_from_obj(objects, obj), 1, 4);
-        code.push_text(quote_str_method_from_obj(objects, obj), 1, 4);
+        code.push_str(&indent::indent_all_by(4, quote_str_repr_from_obj(obj)));
+        code.push('\n');
+
+        code.push_str(&indent::indent_all_by(
+            4,
+            quote_array_method_from_obj(objects, obj),
+        ));
+        code.push('\n');
+
+        code.push_str(&indent::indent_all_by(
+            4,
+            quote_str_method_from_obj(objects, obj),
+        ));
+        code.push('\n');
 
         if obj.kind == ObjectKind::Archetype {
-            code.push_text(quote_builder_from_obj(objects, obj), 1, 4);
+            code.push_str(&indent::indent_all_by(
+                4,
+                quote_builder_from_obj(objects, obj),
+            ));
+            code.push('\n');
         } else {
-            code.push_text(quote_aliases_from_object(obj), 1, 4);
+            code.push_str(&quote_aliases_from_object(obj));
+            code.push('\n');
         }
 
-        code.push_text(quote_arrow_support_from_obj(arrow_registry, obj), 1, 4);
+        code.push_str(&quote_arrow_support_from_obj(arrow_registry, obj));
+        code.push('\n');
 
         let mut filepath = PathBuf::from(filepath);
         filepath.set_extension("py");
@@ -356,28 +360,26 @@ impl QuotedObject {
 
         let mut code = String::new();
 
-        code.push_text(&quote_module_prelude(), 0, 0);
+        code.push_str(&quote_module_prelude());
 
         for clause in obj
             .fields
             .iter()
             .filter_map(quote_import_clauses_from_field)
         {
-            code.push_text(&clause, 1, 0);
+            code.push_str(&clause);
+            code.push('\n');
         }
 
-        code.push_unindented_text(
-            format!(
-                r#"
+        code.push_str(&unindent::unindent(&format!(
+            r#"
 
-                @dataclass
-                class {name}:
-                "#
-            ),
-            0,
-        );
+            @dataclass
+            class {name}:
+            "#
+        )));
 
-        code.push_text(quote_doc_from_docs(docs), 0, 4);
+        code.push_str(&indent::indent_all_by(4, quote_doc_from_docs(docs)));
 
         for field in fields {
             let ObjectField {
@@ -394,16 +396,34 @@ impl QuotedObject {
 
             let (typ, _) = quote_field_type_from_field(objects, field, false);
             // NOTE: It's always optional since only one of the fields can be set at a time.
-            code.push_text(format!("{name}: {typ} | None = None"), 1, 4);
+            code.push_str(&indent::indent_all_by(
+                4,
+                format!("{name}: Optional[{typ}] = None\n"),
+            ));
 
-            code.push_text(quote_doc_from_docs(docs), 0, 4);
+            code.push_str(&indent::indent_all_by(4, quote_doc_from_docs(docs)));
         }
 
-        code.push_text(quote_str_repr_from_obj(obj), 1, 4);
-        code.push_text(quote_array_method_from_obj(objects, obj), 1, 4);
-        code.push_text(quote_str_method_from_obj(objects, obj), 1, 4);
-        code.push_text(quote_aliases_from_object(obj), 1, 4);
-        code.push_text(quote_arrow_support_from_obj(arrow_registry, obj), 1, 4);
+        code.push_str(&indent::indent_all_by(4, quote_str_repr_from_obj(obj)));
+        code.push('\n');
+
+        code.push_str(&indent::indent_all_by(
+            4,
+            quote_array_method_from_obj(objects, obj),
+        ));
+        code.push('\n');
+
+        code.push_str(&indent::indent_all_by(
+            4,
+            quote_str_method_from_obj(objects, obj),
+        ));
+        code.push('\n');
+
+        code.push_str(&quote_aliases_from_object(obj));
+        code.push('\n');
+
+        code.push_str(&quote_arrow_support_from_obj(arrow_registry, obj));
+        code.push('\n');
 
         let mut filepath = PathBuf::from(filepath);
         filepath.set_extension("py");
@@ -419,20 +439,12 @@ impl QuotedObject {
 
 // --- Code generators ---
 
-fn quote_manifest(names: impl IntoIterator<Item = impl AsRef<str>>) -> String {
-    let mut quoted_names: Vec<_> = names
-        .into_iter()
-        .map(|name| format!("{:?}", name.as_ref()))
-        .collect();
-    quoted_names.sort();
-
-    quoted_names.join(", ")
-}
-
 fn quote_module_prelude() -> String {
-    // NOTE: All the extraneous stuff will be cleaned up courtesy of `ruff`.
+    // NOTE: All the extraneous stull will be cleaned up courtesy of `ruff`.
     unindent::unindent(
         r#"
+        from __future__ import annotations
+
         import numpy as np
         import numpy.typing as npt
         import pyarrow as pa
@@ -544,43 +556,38 @@ fn quote_str_method_from_obj(objects: &Objects, obj: &Object) -> String {
 fn quote_aliases_from_object(obj: &Object) -> String {
     assert!(obj.kind != ObjectKind::Archetype);
 
-    let aliases = obj.try_get_attr::<String>(PYTHON_ATTR_ALIASES);
+    let aliases = obj.try_get_attr::<String>(ATTR_ALIASES);
     let array_aliases = obj
-        .try_get_attr::<String>(PYTHON_ATTR_ARRAY_ALIASES)
+        .try_get_attr::<String>(ATTR_ARRAY_ALIASES)
         .unwrap_or_default();
 
     let name = &obj.name;
 
     let mut code = String::new();
 
-    code.push_unindented_text(
-        &if let Some(aliases) = aliases {
-            format!(
-                r#"
-                {name}Like = Union[
-                    {name},
-                    {aliases}
-                ]
-                "#,
-            )
-        } else {
-            format!("{name}Like = {name}")
-        },
-        1,
-    );
-
-    code.push_unindented_text(
-        format!(
+    code.push_str(&if let Some(aliases) = aliases {
+        unindent::unindent(&format!(
             r#"
-            {name}ArrayLike = Union[
-                {name}Like,
-                Sequence[{name}Like],
-                {array_aliases}
+            {name}Like = Union[
+                {name},
+                {aliases}
             ]
+
             "#,
-        ),
-        0,
-    );
+        ))
+    } else {
+        format!("{name}Like = {name}\n")
+    });
+
+    code.push_str(&unindent::unindent(&format!(
+        r#"
+        {name}ArrayLike = Union[
+            {name}Like,
+            Sequence[{name}Like],
+            {array_aliases}
+        ]
+        "#,
+    )));
 
     code
 }
@@ -621,10 +628,6 @@ fn quote_import_clauses_from_field(field: &ObjectField) -> Option<String> {
 }
 
 /// Returns type name as string and whether it was force unwrapped.
-///
-/// Specifying `unwrap = true` will unwrap the final type before returning it, e.g. `Vec<String>`
-/// becomes just `String`.
-/// The returned boolean indicates whether there was anything to unwrap at all.
 fn quote_field_type_from_field(
     objects: &Objects,
     field: &ObjectField,
@@ -681,9 +684,7 @@ fn quote_field_type_from_field(
             // TODO(cmc): it is a bit weird to be doing the transparency logic (which is language
             // agnostic) in a python specific quoting function... a static helper at the very least
             // would be nice.
-            let is_transparent = field
-                .try_get_attr::<String>(PYTHON_ATTR_TRANSPARENT)
-                .is_some();
+            let is_transparent = field.try_get_attr::<String>(ATTR_TRANSPARENT).is_some();
             if is_transparent {
                 let target = objects.get(fqname);
                 assert!(
@@ -721,6 +722,7 @@ fn quote_type_from_element_type(typ: &ElementType) -> String {
         ElementType::Object(fqname) => {
             let (from, class) = fqname.rsplit_once('.').unwrap_or(("", fqname.as_str()));
             if from.starts_with("rerun.datatypes") {
+                // NOTE: Only need the class name, pre-generated import clause takes care of the rest.
                 format!("datatypes.{class}")
             } else if from.starts_with("rerun.components") {
                 format!("components.{class}")
@@ -794,11 +796,11 @@ fn quote_arrow_support_from_obj(arrow_registry: &ArrowRegistry, obj: &Object) ->
 
                 class {many}(pa.ExtensionArray, {many}Ext):  # type: ignore[misc]
                     @staticmethod
-                    def from_similar(data: {many_aliases} | None):
+                    def from_similar(data: Optional[{many_aliases}]):
                         if data is None:
                             return {arrow}().wrap_array(pa.array([], type={arrow}().storage_type))
                         else:
-                            return {many}Ext._from_similar(
+                            return {many}Ext.from_similar(
                                 data,
                                 mono={mono},
                                 mono_aliases={mono_aliases},
@@ -806,7 +808,7 @@ fn quote_arrow_support_from_obj(arrow_registry: &ArrowRegistry, obj: &Object) ->
                                 many_aliases={many_aliases},
                                 arrow={arrow},
                             )
-                "#
+            "#
             ))
         }
         ObjectKind::Archetype => String::new(),
@@ -849,42 +851,38 @@ fn quote_builder_from_obj(objects: &Objects, obj: &Object) -> String {
             let (typ, unwrapped) = quote_field_type_from_field(objects, field, true);
             if unwrapped {
                 // This was originally a vec/array!
-                format!("{}: {typ}ArrayLike | None = None", field.name)
+                format!("{}: Optional[{typ}ArrayLike] = None", field.name)
             } else {
-                format!("{}: {typ}Like | None = None", field.name)
+                format!("{}: Optional[{typ}Like] = None", field.name)
             }
         })
         .collect::<Vec<_>>()
         .join(", ");
 
-    code.push_text(
-        format!("def __init__(self, {required_args}, *, {optional_args}) -> None:"),
-        1,
-        0,
-    );
+    code.push_str(&format!(
+        "def __init__(self, {required_args}, *, {optional_args}) -> None:\n"
+    ));
 
-    code.push_text("# Required components", 1, 4);
+    code.push_str(&indent::indent_all_by(4, "# Required components\n"));
     for field in required {
         let name = &field.name;
         let (typ, _) = quote_field_type_from_field(objects, field, true);
-        code.push_text(
-            format!("self.{name} = {typ}Array.from_similar({name})"),
-            1,
+        code.push_str(&indent::indent_all_by(
             4,
-        );
+            format!("self.{name} = {typ}Array.from_similar({name})\n"),
+        ));
     }
 
     code.push('\n');
 
-    code.push_text("# Optional components\n", 1, 4);
+    code.push_str(&indent::indent_all_by(4, "# Optional components\n"));
     for field in optional {
         let name = &field.name;
         let (typ, _) = quote_field_type_from_field(objects, field, true);
-        code.push_text(
-            format!("self.{name} = {typ}Array.from_similar({name})"),
-            1,
+        code.push_str(&indent::indent_all_by(
             4,
-        );
+            format!("self.{name} = {typ}Array.from_similar({name})\n"),
+        ));
     }
 
     code
@@ -938,7 +936,11 @@ fn quote_arrow_datatype(datatype: &DataType) -> String {
                 .join(", ");
             format!("pa.struct([{fields}])")
         }
-        DataType::Extension(_, datatype, _) => quote_arrow_datatype(datatype),
+        DataType::Extension(_, datatype, _) => {
+            // TODO(cmc): not sure we need all that for the python backend since we already
+            // do the wrapping trick...?
+            quote_arrow_datatype(datatype)
+        }
         _ => unimplemented!("{datatype:#?}"), // NOLINT
     }
 }
diff --git a/crates/re_types_builder/src/codegen/rust.rs b/crates/re_types_builder/src/codegen/rust.rs
index ae87dedf9398..588c5ebc7663 100644
--- a/crates/re_types_builder/src/codegen/rust.rs
+++ b/crates/re_types_builder/src/codegen/rust.rs
@@ -8,14 +8,21 @@ use std::{
 };
 
 use crate::{
-    codegen::{StringExt as _, AUTOGEN_WARNING},
+    codegen::{
+        AUTOGEN_WARNING, RERUN_ATTR_COMPONENT_OPTIONAL, RERUN_ATTR_COMPONENT_RECOMMENDED,
+        RERUN_ATTR_COMPONENT_REQUIRED,
+    },
     ArrowRegistry, CodeGenerator, Docs, ElementType, Object, ObjectField, ObjectKind, Objects,
-    Type, RERUN_ATTR_COMPONENT_OPTIONAL, RERUN_ATTR_COMPONENT_RECOMMENDED,
-    RERUN_ATTR_COMPONENT_REQUIRED, RUST_ATTR_DERIVE, RUST_ATTR_REPR, RUST_ATTR_TUPLE_STRUCT,
+    Type,
 };
 
 // ---
 
+// TODO(cmc): find a way to extract attr name constants directly from the IDL definitions
+pub const ATTR_DERIVE: &str = "rust.attr.derive";
+pub const ATTR_REPR: &str = "rust.attr.repr";
+pub const ATTR_TUPLE_STRUCT: &str = "rust.attr.tuple_struct";
+
 pub struct RustCodeGenerator {
     crate_path: PathBuf,
 }
@@ -86,7 +93,15 @@ fn quote_objects(
         };
 
         let filepath = out_path.join(obj.filepath.file_name().unwrap());
-        files.entry(filepath.clone()).or_default().push(obj);
+
+        match files.entry(filepath.clone()) {
+            std::collections::hash_map::Entry::Occupied(mut entry) => {
+                entry.get_mut().push(obj);
+            }
+            std::collections::hash_map::Entry::Vacant(entry) => {
+                entry.insert(vec![obj]);
+            }
+        };
     }
 
     // (module_name, [object_name])
@@ -97,9 +112,14 @@ fn quote_objects(
         // NOTE: Isolating the file stem only works because we're handling datatypes, components
         // and archetypes separately (and even then it's a bit shady, eh).
         let names = objs.iter().map(|obj| obj.name.clone()).collect::<Vec<_>>();
-        mods.entry(filepath.file_stem().unwrap().to_string_lossy().to_string())
-            .or_default()
-            .extend(names);
+        match mods.entry(filepath.file_stem().unwrap().to_string_lossy().to_string()) {
+            std::collections::hash_map::Entry::Occupied(mut entry) => {
+                entry.get_mut().extend(names);
+            }
+            std::collections::hash_map::Entry::Vacant(entry) => {
+                entry.insert(names);
+            }
+        };
 
         filepaths.push(filepath.clone());
         let mut file = std::fs::File::create(&filepath)
@@ -107,10 +127,11 @@ fn quote_objects(
             .unwrap();
 
         let mut code = String::new();
-        code.push_text(format!("// {AUTOGEN_WARNING}"), 2, 0);
+        code.push_str(&format!("// {AUTOGEN_WARNING}\n\n"));
 
         for obj in objs {
-            code.push_text(&obj.code, 1, 0);
+            code.push_str(&obj.code);
+            code.push('\n');
         }
         file.write_all(code.as_bytes())
             .with_context(|| format!("{filepath:?}"))
@@ -123,17 +144,17 @@ fn quote_objects(
 
         let mut code = String::new();
 
-        code.push_text(format!("// {AUTOGEN_WARNING}"), 2, 0);
+        code.push_str(&format!("// {AUTOGEN_WARNING}\n\n"));
 
         for module in mods.keys() {
-            code.push_text(format!("mod {module};"), 1, 0);
+            code.push_str(&format!("mod {module};\n"));
 
-            // Detect if someone manually created an extension file, and automatically
+            // NOTE: detect if someone manually created an extension file, and automatically
             // import it if so.
             let mut ext_path = out_path.join(format!("{module}_ext"));
             ext_path.set_extension("rs");
             if ext_path.exists() {
-                code.push_text(format!("mod {module}_ext;"), 1, 0);
+                code.push_str(&format!("mod {module}_ext;\n"));
             }
         }
 
@@ -141,7 +162,7 @@ fn quote_objects(
 
         for (module, names) in &mods {
             let names = names.join(", ");
-            code.push_text(format!("pub use self::{module}::{{{names}}};"), 1, 0);
+            code.push_str(&format!("pub use self::{module}::{{{names}}};\n"));
         }
 
         filepaths.push(path.clone());
@@ -180,21 +201,23 @@ impl QuotedObject {
 
         let mut code = String::new();
 
-        code.push_text(&quote_doc_from_docs(docs), 0, 0);
+        code.push_str(&quote_doc_from_docs(docs));
 
         if let Some(clause) = quote_derive_clause_from_obj(obj) {
-            code.push_text(&clause, 1, 0);
+            code.push_str(&clause);
+            code.push('\n');
         }
         if let Some(clause) = quote_repr_clause_from_obj(obj) {
-            code.push_text(&clause, 1, 0);
+            code.push_str(&clause);
+            code.push('\n');
         }
 
         let is_tuple_struct = is_tuple_struct_from_obj(obj);
 
         if is_tuple_struct {
-            code.push_text(&format!("pub struct {name}("), 0, 0);
+            code.push_str(&format!("pub struct {name}("));
         } else {
-            code.push_text(&format!("pub struct {name} {{"), 1, 0);
+            code.push_str(&format!("pub struct {name} {{\n"));
         }
 
         for field in fields {
@@ -207,11 +230,11 @@ impl QuotedObject {
                 typ: _,
                 attrs: _,
                 required,
-                // TODO(#2366): support for deprecation notices
+                // TODO(cmc): support for deprecation notices
                 deprecated: _,
             } = field;
 
-            code.push_text(&quote_doc_from_docs(docs), 0, 0);
+            code.push_str(&quote_doc_from_docs(docs));
 
             let (typ, _) = quote_field_type_from_field(field, false);
             let typ = if *required {
@@ -221,9 +244,9 @@ impl QuotedObject {
             };
 
             if is_tuple_struct {
-                code.push_text(&format!("pub {typ}"), 0, 0);
+                code.push_str(&format!("pub {typ}"));
             } else {
-                code.push_text(&format!("pub {name}: {typ},"), 2, 0);
+                code.push_str(&format!("pub {name}: {typ},\n\n"));
             }
         }
 
@@ -233,10 +256,11 @@ impl QuotedObject {
             code += "}\n\n";
         }
 
-        code.push_text(&quote_trait_impls_from_obj(arrow_registry, obj), 1, 0);
+        code.push_str(&quote_trait_impls_from_obj(arrow_registry, obj));
+        code.push('\n');
 
         if kind == &ObjectKind::Archetype {
-            code.push_text(&quote_builder_from_obj(obj), 0, 0);
+            code.push_str(&quote_builder_from_obj(obj));
         }
 
         let mut filepath = PathBuf::from(filepath);
@@ -266,16 +290,18 @@ impl QuotedObject {
 
         let mut code = String::new();
 
-        code.push_text(&quote_doc_from_docs(docs), 0, 0);
+        code.push_str(&quote_doc_from_docs(docs));
 
         if let Some(clause) = quote_derive_clause_from_obj(obj) {
-            code.push_text(&clause, 1, 0);
+            code.push_str(&clause);
+            code.push('\n');
         }
         if let Some(clause) = quote_repr_clause_from_obj(obj) {
-            code.push_text(&clause, 1, 0);
+            code.push_str(&clause);
+            code.push('\n');
         }
 
-        code.push_text(&format!("pub enum {name} {{"), 1, 0);
+        code.push_str(&format!("pub enum {name} {{\n"));
 
         for field in fields {
             let ObjectField {
@@ -290,16 +316,17 @@ impl QuotedObject {
                 deprecated: _,
             } = field;
 
-            code.push_text(&quote_doc_from_docs(docs), 0, 0);
+            code.push_str(&quote_doc_from_docs(docs));
 
             let (typ, _) = quote_field_type_from_field(field, false);
 
-            code.push_text(&format!("{name}({typ}),"), 2, 0);
+            code.push_str(&format!("{name}({typ}),\n\n"));
         }
 
         code += "}\n\n";
 
-        code.push_text(&quote_trait_impls_from_obj(arrow_registry, obj), 1, 0);
+        code.push_str(&quote_trait_impls_from_obj(arrow_registry, obj));
+        code.push('\n');
 
         let mut filepath = PathBuf::from(filepath);
         filepath.set_extension("rs");
@@ -327,14 +354,9 @@ fn quote_doc_from_docs(docs: &Docs) -> String {
 }
 
 /// Returns type name as string and whether it was force unwrapped.
-///
-/// Specifying `unwrap = true` will unwrap the final type before returning it, e.g. `Vec<String>`
-/// becomes just `String`.
-/// The returned boolean indicates whether there was anything to unwrap at all.
 fn quote_field_type_from_field(field: &ObjectField, unwrap: bool) -> (String, bool) {
     let mut unwrapped = false;
-    let typ = &field.typ;
-    let typ = match typ {
+    let typ = match &field.typ {
         Type::UInt8 => "u8".to_owned(),
         Type::UInt16 => "u16".to_owned(),
         Type::UInt32 => "u32".to_owned(),
@@ -344,9 +366,10 @@ fn quote_field_type_from_field(field: &ObjectField, unwrap: bool) -> (String, bo
         Type::Int32 => "i32".to_owned(),
         Type::Int64 => "i64".to_owned(),
         Type::Bool => "bool".to_owned(),
-        Type::Float16 => unimplemented!("{typ:#?}"), // NOLINT
+        Type::Float16 => unimplemented!("ResolvedType::Float16"), // NOLINT
         Type::Float32 => "f32".to_owned(),
         Type::Float64 => "f64".to_owned(),
+        // TODO(cmc): ref for deserialization?
         Type::String => "String".to_owned(),
         Type::Array { elem_type, length } => {
             let typ = quote_type_from_element_type(elem_type);
@@ -383,28 +406,29 @@ fn quote_type_from_element_type(typ: &ElementType) -> String {
         ElementType::Int32 => "i32".to_owned(),
         ElementType::Int64 => "i64".to_owned(),
         ElementType::Bool => "bool".to_owned(),
-        ElementType::Float16 => unimplemented!("{typ:#?}"), // NOLINT
+        ElementType::Float16 => unimplemented!("ResolvedType::Float16"), // NOLINT
         ElementType::Float32 => "f32".to_owned(),
         ElementType::Float64 => "f64".to_owned(),
+        // TODO(cmc): ref for deserialization?
         ElementType::String => "String".to_owned(),
         ElementType::Object(fqname) => fqname.replace('.', "::").replace("rerun", "crate"),
     }
 }
 
 fn quote_derive_clause_from_obj(obj: &Object) -> Option<String> {
-    obj.try_get_attr::<String>(RUST_ATTR_DERIVE)
+    obj.try_get_attr::<String>(ATTR_DERIVE)
         .map(|what| format!("#[derive({what})]"))
 }
 
 fn quote_repr_clause_from_obj(obj: &Object) -> Option<String> {
-    obj.try_get_attr::<String>(RUST_ATTR_REPR)
+    obj.try_get_attr::<String>(ATTR_REPR)
         .map(|what| format!("#[repr({what})]"))
 }
 
 fn is_tuple_struct_from_obj(obj: &Object) -> bool {
     obj.is_struct()
         && obj.fields.len() == 1
-        && obj.try_get_attr::<String>(RUST_ATTR_TUPLE_STRUCT).is_some()
+        && obj.try_get_attr::<String>(ATTR_TUPLE_STRUCT).is_some()
 }
 
 fn quote_trait_impls_from_obj(arrow_registry: &ArrowRegistry, obj: &Object) -> String {
@@ -512,7 +536,6 @@ fn quote_trait_impls_from_obj(arrow_registry: &ArrowRegistry, obj: &Object) -> S
 
                     #[allow(clippy::unimplemented)]
                     fn to_arrow_datatypes() -> Vec<arrow2::datatypes::DataType> {{
-                        // TODO(#2368): dump the arrow registry into the generated code
                         unimplemented!("query the registry for all fqnames"); // NOLINT
                     }}
                 }}
@@ -549,7 +572,7 @@ fn quote_builder_from_obj(obj: &Object) -> String {
 
     let mut code = String::new();
 
-    code.push_text(&format!("impl {name} {{"), 1, 0);
+    code.push_str(&format!("impl {name} {{\n"));
     {
         // --- impl new() ---
 
@@ -569,7 +592,7 @@ fn quote_builder_from_obj(obj: &Object) -> String {
             })
             .collect::<Vec<_>>()
             .join(", ");
-        code.push_text(&format!("pub fn new({new_params}) -> Self {{"), 1, 0);
+        code.push_str(&format!("pub fn new({new_params}) -> Self {{\n"));
         {
             code += "Self {\n";
             {
@@ -577,20 +600,16 @@ fn quote_builder_from_obj(obj: &Object) -> String {
                     let (_, unwrapped) = quote_field_type_from_field(field, true);
                     if unwrapped {
                         // This was originally a vec/array!
-                        code.push_text(
-                            &format!(
-                                "{}: {}.into_iter().map(Into::into).collect(),",
-                                field.name, field.name
-                            ),
-                            1,
-                            0,
-                        );
+                        code.push_str(&format!(
+                            "{}: {}.into_iter().map(Into::into).collect(),\n",
+                            field.name, field.name
+                        ));
                     } else {
-                        code.push_text(&format!("{}: {}.into(),", field.name, field.name), 1, 0);
+                        code.push_str(&format!("{}: {}.into(),\n", field.name, field.name));
                     }
                 }
                 for field in &optional {
-                    code.push_text(&format!("{}: None,", field.name), 1, 0);
+                    code.push_str(&format!("{}: None,\n", field.name));
                 }
             }
             code += "}\n";
@@ -605,27 +624,21 @@ fn quote_builder_from_obj(obj: &Object) -> String {
 
             if unwrapped {
                 // This was originally a vec/array!
-                code.push_text(&format!(
-                    "pub fn with_{name}(mut self, {name}: impl IntoIterator<Item = impl Into<{typ}>>) -> Self {{",
-                ), 1, 0);
+                code.push_str(&format!(
+                    "pub fn with_{name}(mut self, {name}: impl IntoIterator<Item = impl Into<{typ}>>) -> Self {{\n",
+                ));
                 {
-                    code.push_text(
-                        &format!(
-                            "self.{name} = Some({name}.into_iter().map(Into::into).collect());"
-                        ),
-                        1,
-                        0,
-                    );
+                    code.push_str(&format!(
+                        "self.{name} = Some({name}.into_iter().map(Into::into).collect());\n"
+                    ));
                     code += "self\n";
                 }
             } else {
-                code.push_text(
-                    &format!("pub fn with_{name}(mut self, {name}: impl Into<{typ}>) -> Self {{",),
-                    1,
-                    0,
-                );
+                code.push_str(&format!(
+                    "pub fn with_{name}(mut self, {name}: impl Into<{typ}>) -> Self {{\n",
+                ));
                 {
-                    code.push_text(&format!("self.{name} = Some({name}.into());"), 1, 0);
+                    code.push_str(&format!("self.{name} = Some({name}.into());\n"));
                     code += "self\n";
                 }
             }
diff --git a/crates/re_types_builder/src/lib.rs b/crates/re_types_builder/src/lib.rs
index 71669189d7f6..b15e3704e1b0 100644
--- a/crates/re_types_builder/src/lib.rs
+++ b/crates/re_types_builder/src/lib.rs
@@ -18,7 +18,7 @@
 //! ####. 2. Run the semantic pass.
 //!
 //! The semantic pass transforms the low-level raw reflection data generated by the first phase
-//! into higher level objects that are much easier to inspect/manipulate and overall friendlier
+//! into higher level objects that are much easier to inspect/manipulate and overall friendler
 //! to work with.
 //!
 //! Look for `objects.rs`.
@@ -61,8 +61,6 @@
 //!
 //! Make sure to test the behavior of its output though: `re_types`!
 
-// TODO(#2365): support for external IDL definitions
-
 // ---
 
 // NOTE: Official generated code from flatbuffers; ignore _everything_.
@@ -99,31 +97,12 @@ pub use self::objects::{
     Attributes, Docs, ElementType, Object, ObjectField, ObjectKind, Objects, Type,
 };
 
-// --- Attributes ---
-
-pub const ARROW_ATTR_TRANSPARENT: &str = "arrow.attr.transparent";
-pub const ARROW_ATTR_SPARSE_UNION: &str = "arrow.attr.sparse_union";
-
-pub const RERUN_ATTR_COMPONENT_REQUIRED: &str = "rerun.attr.component_required";
-pub const RERUN_ATTR_COMPONENT_RECOMMENDED: &str = "rerun.attr.component_recommended";
-pub const RERUN_ATTR_COMPONENT_OPTIONAL: &str = "rerun.attr.component_optional";
-
-pub const PYTHON_ATTR_TRANSPARENT: &str = "python.attr.transparent";
-pub const PYTHON_ATTR_ALIASES: &str = "python.attr.aliases";
-pub const PYTHON_ATTR_ARRAY_ALIASES: &str = "python.attr.array_aliases";
-
-pub const RUST_ATTR_DERIVE: &str = "rust.attr.derive";
-pub const RUST_ATTR_REPR: &str = "rust.attr.repr";
-pub const RUST_ATTR_TUPLE_STRUCT: &str = "rust.attr.tuple_struct";
-
 // --- Entrypoints ---
 
 use std::path::{Path, PathBuf};
 
 /// Compiles binary reflection dumps from flatbuffers definitions.
 ///
-/// Requires `flatc` available in $PATH.
-///
 /// Panics on error.
 ///
 /// - `include_dir_path`: path to the root directory of the fbs definition tree.
@@ -160,14 +139,28 @@ pub fn compile_binary_schemas(
     .unwrap();
 }
 
-/// Handles the first 3 language-agnostic passes of the codegen pipeline:
-/// 1. Generate binary reflection dumps for our definitions.
-/// 2. Run the semantic pass
-/// 3. Compute the Arrow registry
-fn generate_lang_agnostic(
+/// Generates Rust code from a set of flatbuffers definitions.
+///
+/// Panics on error.
+///
+/// - `include_dir_path`: path to the root directory of the fbs definition tree.
+/// - `output_crate_path`: path to the root of the output crate.
+/// - `entrypoint_path`: path to the root file of the fbs definition tree.
+/// - `source_hash`: optional sha256 hash of the source definition files.
+///
+/// E.g.:
+/// ```no_run
+/// re_types_builder::generate_rust_code(
+///     "./definitions",
+///     ".",
+///     "./definitions/rerun/archetypes.fbs",
+/// );
+/// ```
+pub fn generate_rust_code(
     include_dir_path: impl AsRef<Path>,
+    output_crate_path: impl AsRef<Path>,
     entrypoint_path: impl AsRef<Path>,
-) -> (Objects, ArrowRegistry) {
+) {
     use xshell::Shell;
 
     let sh = Shell::new().unwrap();
@@ -195,33 +188,6 @@ fn generate_lang_agnostic(
         arrow_registry.register(obj);
     }
 
-    (objects, arrow_registry)
-}
-
-/// Generates Rust code from a set of flatbuffers definitions.
-///
-/// Panics on error.
-///
-/// - `include_dir_path`: path to the root directory of the fbs definition tree.
-/// - `output_crate_path`: path to the root of the output crate.
-/// - `entrypoint_path`: path to the root file of the fbs definition tree.
-///
-/// E.g.:
-/// ```no_run
-/// re_types_builder::generate_rust_code(
-///     "./definitions",
-///     ".",
-///     "./definitions/rerun/archetypes.fbs",
-/// );
-/// ```
-pub fn generate_rust_code(
-    include_dir_path: impl AsRef<Path>,
-    output_crate_path: impl AsRef<Path>,
-    entrypoint_path: impl AsRef<Path>,
-) {
-    // passes 1 through 3: bfbs, semantic, arrow registry
-    let (objects, arrow_registry) = generate_lang_agnostic(include_dir_path, entrypoint_path);
-
     // generate rust code
     let mut gen = RustCodeGenerator::new(output_crate_path.as_ref());
     let _filepaths = gen.quote(&objects, &arrow_registry);
@@ -248,8 +214,32 @@ pub fn generate_python_code(
     output_pkg_path: impl AsRef<Path>,
     entrypoint_path: impl AsRef<Path>,
 ) {
-    // passes 1 through 3: bfbs, semantic, arrow registry
-    let (objects, arrow_registry) = generate_lang_agnostic(include_dir_path, entrypoint_path);
+    use xshell::Shell;
+
+    let sh = Shell::new().unwrap();
+    let tmp = sh.create_temp_dir().unwrap();
+
+    let entrypoint_path = entrypoint_path.as_ref();
+    let entrypoint_filename = entrypoint_path.file_name().unwrap();
+
+    // generate bfbs definitions
+    compile_binary_schemas(include_dir_path, tmp.path(), entrypoint_path);
+
+    let mut binary_entrypoint_path = PathBuf::from(entrypoint_filename);
+    binary_entrypoint_path.set_extension("bfbs");
+
+    // semantic pass: high level objects from low-level reflection data
+    let objects = Objects::from_buf(
+        sh.read_binary_file(tmp.path().join(binary_entrypoint_path))
+            .unwrap()
+            .as_slice(),
+    );
+
+    // create and fill out arrow registry
+    let mut arrow_registry = ArrowRegistry::default();
+    for obj in objects.ordered_objects(None) {
+        arrow_registry.register(obj);
+    }
 
     // generate python code
     let mut gen = PythonCodeGenerator::new(output_pkg_path.as_ref());
diff --git a/crates/re_types_builder/src/objects.rs b/crates/re_types_builder/src/objects.rs
index 677779a7c7b3..4f6168c9667d 100644
--- a/crates/re_types_builder/src/objects.rs
+++ b/crates/re_types_builder/src/objects.rs
@@ -124,22 +124,6 @@ pub enum ObjectKind {
     Archetype,
 }
 
-impl ObjectKind {
-    // TODO(#2364): use an attr instead of the path
-    pub fn from_pkg_name(pkg_name: impl AsRef<str>) -> Self {
-        let pkg_name = pkg_name.as_ref();
-        if pkg_name.starts_with("rerun.datatypes") {
-            ObjectKind::Datatype
-        } else if pkg_name.starts_with("rerun.components") {
-            ObjectKind::Component
-        } else if pkg_name.starts_with("rerun.archetypes") {
-            ObjectKind::Archetype
-        } else {
-            panic!("unknown package {pkg_name:?}");
-        }
-    }
-}
-
 /// A high-level representation of a flatbuffers object's documentation.
 #[derive(Debug, Clone)]
 pub struct Docs {
@@ -272,7 +256,18 @@ impl Object {
             .unwrap();
 
         let docs = Docs::from_raw_docs(obj.documentation());
-        let kind = ObjectKind::from_pkg_name(&pkg_name);
+
+        let kind = if pkg_name.starts_with("rerun.datatypes") {
+            ObjectKind::Datatype
+        } else if pkg_name.starts_with("rerun.components") {
+            ObjectKind::Component
+        } else if pkg_name.starts_with("rerun.archetypes") {
+            ObjectKind::Archetype
+        } else {
+            // TODO(cmc): support IDL definitions from outside the repo
+            panic!("unknown package {pkg_name:?}");
+        };
+
         let attrs = Attributes::from_raw_attrs(obj.attributes());
 
         let fields = {
@@ -317,7 +312,17 @@ impl Object {
             .unwrap();
 
         let docs = Docs::from_raw_docs(enm.documentation());
-        let kind = ObjectKind::from_pkg_name(&pkg_name);
+
+        let kind = if pkg_name.starts_with("rerun.datatypes") {
+            ObjectKind::Datatype
+        } else if pkg_name.starts_with("rerun.components") {
+            ObjectKind::Component
+        } else if pkg_name.starts_with("rerun.archetypes") {
+            ObjectKind::Archetype
+        } else {
+            // TODO(cmc): support IDL definitions from outside the repo
+            panic!("unknown package {pkg_name:?}");
+        };
 
         let utype = {
             if enm.underlying_type().base_type() == FbsBaseType::UType {
@@ -443,13 +448,12 @@ pub struct ObjectField {
 
     /// Whether the field is required.
     ///
-    /// Always true for IDL definitions using flatbuffers' `struct` type (as opposed to `table`).
+    /// Always true for `struct` types.
     pub required: bool,
 
     /// Whether the field is deprecated.
     //
-    // TODO(#2366): do something with this
-    // TODO(#2367): implement custom attr to specify deprecation reason
+    // TODO(cmc): implement custom attr to specify deprecation reason
     pub deprecated: bool,
 }
 
@@ -566,7 +570,7 @@ impl ObjectField {
     }
 }
 
-/// The underlying type of an [`ObjectField`].
+/// The underlying type of a `ResolvedObjectField`.
 #[derive(Debug, Clone)]
 pub enum Type {
     UInt8,
@@ -592,35 +596,24 @@ pub enum Type {
     Object(String), // fqname
 }
 
-impl From<ElementType> for Type {
-    fn from(typ: ElementType) -> Self {
-        match typ {
-            ElementType::UInt8 => Self::UInt8,
-            ElementType::UInt16 => Self::UInt16,
-            ElementType::UInt32 => Self::UInt32,
-            ElementType::UInt64 => Self::UInt64,
-            ElementType::Int8 => Self::Int8,
-            ElementType::Int16 => Self::Int16,
-            ElementType::Int32 => Self::Int32,
-            ElementType::Int64 => Self::Int64,
-            ElementType::Bool => Self::Bool,
-            ElementType::Float16 => Self::Float16,
-            ElementType::Float32 => Self::Float32,
-            ElementType::Float64 => Self::Float64,
-            ElementType::String => Self::String,
-            ElementType::Object(fqname) => Self::Object(fqname),
-        }
-    }
-}
-
 impl Type {
     pub fn from_raw_type(
         enums: &[FbsEnum<'_>],
         objs: &[FbsObject<'_>],
         field_type: FbsType<'_>,
     ) -> Self {
-        let typ = field_type.base_type();
-        match typ {
+        fn flatten_scalar_wrappers(obj: &FbsObject<'_>) -> Type {
+            if obj.name().starts_with("fbs.scalars.") {
+                match obj.name() {
+                    "fbs.scalars.Float32" => Type::Float32,
+                    _ => unimplemented!(), // NOLINT
+                }
+            } else {
+                Type::Object(obj.name().to_owned())
+            }
+        }
+
+        match field_type.base_type() {
             FbsBaseType::Bool => Self::Bool,
             FbsBaseType::Byte => Self::Int8,
             FbsBaseType::UByte => Self::UInt8,
@@ -636,12 +629,14 @@ impl Type {
             FbsBaseType::String => Self::String,
             FbsBaseType::Obj => {
                 let obj = &objs[field_type.index() as usize];
-                flatten_scalar_wrappers(obj).into()
+                flatten_scalar_wrappers(obj)
             }
             FbsBaseType::Union => {
                 let union = &enums[field_type.index() as usize];
                 Self::Object(union.name().to_owned())
             }
+            // NOTE: flatbuffers doesn't support directly nesting multiple layers of arrays, they
+            // always have to be wrapped into intermediate layers of structs or tables.
             FbsBaseType::Array => Self::Array {
                 elem_type: ElementType::from_raw_base_type(
                     enums,
@@ -659,11 +654,10 @@ impl Type {
                     field_type.element(),
                 ),
             },
-            FbsBaseType::None | FbsBaseType::UType | FbsBaseType::Vector64 => {
-                unimplemented!("{typ:#?}") // NOLINT
-            } // NOLINT
-            // NOTE: `FbsBaseType` isn't actually an enum, it's just a bunch of constants...
-            _ => unreachable!("{typ:#?}"),
+            FbsBaseType::None => unimplemented!(),  // NOLINT
+            FbsBaseType::UType => unimplemented!(), // NOLINT
+            FbsBaseType::Vector64 => unimplemented!(), // NOLINT
+            _ => unreachable!(),
         }
     }
 }
@@ -697,7 +691,18 @@ impl ElementType {
         outer_type: FbsType<'_>,
         inner_type: FbsBaseType,
     ) -> Self {
-        #[allow(clippy::match_same_arms)]
+        /// Helper to turn wrapped scalars into actual scalars.
+        fn flatten_scalar_wrappers(obj: &FbsObject<'_>) -> ElementType {
+            if obj.name().starts_with("fbs.scalars.") {
+                match obj.name() {
+                    "fbs.scalars.Float32" => ElementType::Float32,
+                    _ => unimplemented!(), // NOLINT
+                }
+            } else {
+                ElementType::Object(obj.name().to_owned())
+            }
+        }
+
         match inner_type {
             FbsBaseType::Bool => Self::Bool,
             FbsBaseType::Byte => Self::Int8,
@@ -708,6 +713,7 @@ impl ElementType {
             FbsBaseType::UInt => Self::UInt32,
             FbsBaseType::Long => Self::Int64,
             FbsBaseType::ULong => Self::UInt64,
+            // TODO(cmc): half support
             FbsBaseType::Float => Self::Float32,
             FbsBaseType::Double => Self::Float64,
             FbsBaseType::String => Self::String,
@@ -715,14 +721,15 @@ impl ElementType {
                 let obj = &objs[outer_type.index() as usize];
                 flatten_scalar_wrappers(obj)
             }
-            FbsBaseType::Union => unimplemented!("{inner_type:#?}"), // NOLINT
-            FbsBaseType::None
-            | FbsBaseType::UType
-            | FbsBaseType::Array
-            | FbsBaseType::Vector
-            | FbsBaseType::Vector64 => unreachable!("{inner_type:#?}"),
-            // NOTE: `FbsType` isn't actually an enum, it's just a bunch of constants...
-            _ => unreachable!("{inner_type:#?}"),
+            FbsBaseType::Union => unimplemented!(), // NOLINT
+            // NOTE: flatbuffers doesn't support directly nesting multiple layers of arrays, they
+            // always have to be wrapped into intermediate layers of structs or tables.
+            FbsBaseType::Array => unimplemented!(),  // NOLINT
+            FbsBaseType::None => unimplemented!(),   // NOLINT
+            FbsBaseType::UType => unimplemented!(),  // NOLINT
+            FbsBaseType::Vector => unimplemented!(), // NOLINT
+            FbsBaseType::Vector64 => unimplemented!(), // NOLINT
+            _ => unreachable!(),
         }
     }
 }
@@ -770,10 +777,9 @@ impl Attributes {
         value_str
             .parse()
             .with_context(|| {
-                let type_of_t = std::any::type_name::<T>();
                 format!(
                     "invalid `{name}` attribute for `{owner_fqname}`: \
-                    expected {type_of_t}, got `{value_str}` instead"
+                    expected unsigned integer, got `{value_str}` instead"
                 )
             })
             .unwrap()
@@ -797,26 +803,12 @@ impl Attributes {
             value_str
                 .parse()
                 .with_context(|| {
-                    let type_of_t = std::any::type_name::<T>();
                     format!(
                         "invalid `{name}` attribute for `{owner_fqname}`: \
-                        expected {type_of_t}, got `{value_str}` instead"
+                        expected unsigned integer, got `{value_str}` instead"
                     )
                 })
                 .unwrap(),
         )
     }
 }
-
-/// Helper to turn wrapped scalars into actual scalars.
-fn flatten_scalar_wrappers(obj: &FbsObject<'_>) -> ElementType {
-    let name = obj.name();
-    if name.starts_with("fbs.scalars.") {
-        match name {
-            "fbs.scalars.Float32" => ElementType::Float32,
-            _ => unimplemented!("{name:#?}"), // NOLINT
-        }
-    } else {
-        ElementType::Object(name.to_owned())
-    }
-}

From bf37e5057327cf09a5f936cf9a9218ee6f19402a Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Sun, 11 Jun 2023 17:45:02 +0200
Subject: [PATCH 05/18] generate reflection code

---
 crates/re_types_builder/source_hash.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/re_types_builder/source_hash.txt b/crates/re_types_builder/source_hash.txt
index 2d51980aefb3..f1766f06bb26 100644
--- a/crates/re_types_builder/source_hash.txt
+++ b/crates/re_types_builder/source_hash.txt
@@ -1,4 +1,4 @@
 # This is a sha256 hash for all direct and indirect dependencies of this crate's build script.
 # It can be safely removed at anytime to force the build script to run again.
 # Check out build.rs to see how it's computed.
-674450e64722effea9b29a84c34fab81b9d57497136a8f161561b8e19f7441b2
\ No newline at end of file
+72d936d50287d6c16d0c1b91f86bd74120642c8fc08e885f08dd2b92bb52e8a4
\ No newline at end of file

From a4e8daa2698747e7c42de03022ca2782fabc7e26 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Sun, 11 Jun 2023 17:56:36 +0200
Subject: [PATCH 06/18] unindent 0.1 everywhere

---
 Cargo.lock                         | 14 ++++----------
 crates/re_types_builder/Cargo.toml |  2 +-
 2 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index be455137ee2a..b5c6926c1ca1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3729,7 +3729,7 @@ dependencies = [
  "pyo3-build-config",
  "pyo3-ffi",
  "pyo3-macros",
- "unindent 0.1.11",
+ "unindent",
 ]
 
 [[package]]
@@ -3938,7 +3938,7 @@ dependencies = [
  "glob",
  "sha2",
  "time",
- "unindent 0.1.11",
+ "unindent",
  "walkdir",
 ]
 
@@ -4227,7 +4227,7 @@ dependencies = [
  "thiserror",
  "tobj",
  "type-map",
- "unindent 0.2.1",
+ "unindent",
  "walkdir",
  "wasm-bindgen-futures",
  "web-sys",
@@ -4507,7 +4507,7 @@ dependencies = [
  "flatbuffers",
  "indent",
  "re_build_tools",
- "unindent 0.2.1",
+ "unindent",
  "xshell",
 ]
 
@@ -5801,12 +5801,6 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e1766d682d402817b5ac4490b3c3002d91dfa0d22812f341609f97b08757359c"
 
-[[package]]
-name = "unindent"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5aa30f5ea51ff7edfc797c6d3f9ec8cbd8cfedef5371766b7181d33977f4814f"
-
 [[package]]
 name = "untrusted"
 version = "0.7.1"
diff --git a/crates/re_types_builder/Cargo.toml b/crates/re_types_builder/Cargo.toml
index 01b3cc8efc4a..ffdd334219bd 100644
--- a/crates/re_types_builder/Cargo.toml
+++ b/crates/re_types_builder/Cargo.toml
@@ -25,7 +25,7 @@ arrow2.workspace = true
 convert_case = "0.6"
 flatbuffers = "23.0"
 indent = "0.1"
-unindent = "0.2"
+unindent.workspace = true
 xshell = "0.2"
 
 

From cf290a7eb258e5fdce12174f6321740e652d3a96 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Sun, 11 Jun 2023 20:55:20 +0200
Subject: [PATCH 07/18] self-review

---
 crates/re_types_builder/build.rs              |   6 +-
 crates/re_types_builder/src/arrow_registry.rs |   5 +-
 crates/re_types_builder/src/codegen/mod.rs    |   1 -
 crates/re_types_builder/src/codegen/python.rs |  12 +-
 crates/re_types_builder/src/codegen/rust.rs   |  15 +-
 crates/re_types_builder/src/lib.rs            |   3 +-
 crates/re_types_builder/src/objects.rs        | 140 ++++++++++--------
 7 files changed, 95 insertions(+), 87 deletions(-)

diff --git a/crates/re_types_builder/build.rs b/crates/re_types_builder/build.rs
index 199ee8e2a8bb..5c949bf4f298 100644
--- a/crates/re_types_builder/build.rs
+++ b/crates/re_types_builder/build.rs
@@ -50,6 +50,8 @@ fn main() {
         }
     }
 
+    // NOTE: This requires `flatc` to be in $PATH, but only for contributors, not end users.
+    // Even for contributors, `flatc` won't be needed unless they edit some of the .fbs files.
     let sh = Shell::new().unwrap();
     cmd!(
         sh,
@@ -60,8 +62,8 @@ fn main() {
 
     // NOTE: We're purposefully ignoring the error here.
     //
-    // In the very unlikely chance that the user doesn't have `rustfmt` in their $PATH, there's
-    // still no good reason to fail the build.
+    // In the very unlikely chance that the user doesn't have the `fmt` component installed,
+    // there's still no good reason to fail the build.
     //
     // The CI will catch the unformatted file at PR time and complain appropriately anyhow.
     cmd!(sh, "cargo fmt").run().ok();
diff --git a/crates/re_types_builder/src/arrow_registry.rs b/crates/re_types_builder/src/arrow_registry.rs
index dd07e7fba4d1..e0edc01cddf5 100644
--- a/crates/re_types_builder/src/arrow_registry.rs
+++ b/crates/re_types_builder/src/arrow_registry.rs
@@ -8,7 +8,6 @@ use crate::{ElementType, Object, Type};
 
 // ---
 
-// TODO(cmc): find a way to extract attr name constants directly from the IDL definitions
 pub const ARROW_ATTR_TRANSPARENT: &str = "arrow.attr.transparent";
 pub const ARROW_ATTR_SPARSE_UNION: &str = "arrow.attr.sparse_union";
 
@@ -56,7 +55,6 @@ impl ArrowRegistry {
 
     fn arrow_datatype_from_object(&self, obj: &Object) -> LazyDatatype {
         let is_struct = obj.is_struct();
-
         let is_transparent = obj.try_get_attr::<String>(ARROW_ATTR_TRANSPARENT).is_some();
         let num_fields = obj.fields.len();
 
@@ -170,6 +168,9 @@ impl ArrowRegistry {
 // --- Field ---
 
 /// A yet-to-be-resolved [`arrow2::datatypes::Field`].
+///
+/// Type resolution is a two-pass process as we first need to register all existing types before we
+/// can denormalize their definitions into their parents.
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
 pub struct LazyField {
     /// Its name
diff --git a/crates/re_types_builder/src/codegen/mod.rs b/crates/re_types_builder/src/codegen/mod.rs
index 49bdc9d9278f..eb2e4d553265 100644
--- a/crates/re_types_builder/src/codegen/mod.rs
+++ b/crates/re_types_builder/src/codegen/mod.rs
@@ -15,7 +15,6 @@ pub trait CodeGenerator {
 pub const AUTOGEN_WARNING: &str =
     "NOTE: This file was autogenerated by re_types_builder; DO NOT EDIT.";
 
-// TODO(cmc): find a way to extract attr name constants directly from the IDL definitions
 pub const RERUN_ATTR_COMPONENT_REQUIRED: &str = "rerun.attr.component_required";
 pub const RERUN_ATTR_COMPONENT_RECOMMENDED: &str = "rerun.attr.component_recommended";
 pub const RERUN_ATTR_COMPONENT_OPTIONAL: &str = "rerun.attr.component_optional";
diff --git a/crates/re_types_builder/src/codegen/python.rs b/crates/re_types_builder/src/codegen/python.rs
index 9b6f85970405..2cba90d0a457 100644
--- a/crates/re_types_builder/src/codegen/python.rs
+++ b/crates/re_types_builder/src/codegen/python.rs
@@ -17,7 +17,6 @@ use crate::{
 // NOTE: `rerun2` while we figure out how to integrate back into the main SDK.
 const MODULE_NAME: &str = "rerun2";
 
-// TODO(cmc): find a way to extract attr name constants directly from the IDL definitions
 pub const ATTR_TRANSPARENT: &str = "python.attr.transparent";
 pub const ATTR_ALIASES: &str = "python.attr.aliases";
 pub const ATTR_ARRAY_ALIASES: &str = "python.attr.array_aliases";
@@ -440,7 +439,7 @@ impl QuotedObject {
 // --- Code generators ---
 
 fn quote_module_prelude() -> String {
-    // NOTE: All the extraneous stull will be cleaned up courtesy of `ruff`.
+    // NOTE: All the extraneous stuff will be cleaned up courtesy of `ruff`.
     unindent::unindent(
         r#"
         from __future__ import annotations
@@ -722,7 +721,6 @@ fn quote_type_from_element_type(typ: &ElementType) -> String {
         ElementType::Object(fqname) => {
             let (from, class) = fqname.rsplit_once('.').unwrap_or(("", fqname.as_str()));
             if from.starts_with("rerun.datatypes") {
-                // NOTE: Only need the class name, pre-generated import clause takes care of the rest.
                 format!("datatypes.{class}")
             } else if from.starts_with("rerun.components") {
                 format!("components.{class}")
@@ -808,7 +806,7 @@ fn quote_arrow_support_from_obj(arrow_registry: &ArrowRegistry, obj: &Object) ->
                                 many_aliases={many_aliases},
                                 arrow={arrow},
                             )
-            "#
+                "#
             ))
         }
         ObjectKind::Archetype => String::new(),
@@ -936,11 +934,7 @@ fn quote_arrow_datatype(datatype: &DataType) -> String {
                 .join(", ");
             format!("pa.struct([{fields}])")
         }
-        DataType::Extension(_, datatype, _) => {
-            // TODO(cmc): not sure we need all that for the python backend since we already
-            // do the wrapping trick...?
-            quote_arrow_datatype(datatype)
-        }
+        DataType::Extension(_, datatype, _) => quote_arrow_datatype(datatype),
         _ => unimplemented!("{datatype:#?}"), // NOLINT
     }
 }
diff --git a/crates/re_types_builder/src/codegen/rust.rs b/crates/re_types_builder/src/codegen/rust.rs
index 588c5ebc7663..0a928185ae47 100644
--- a/crates/re_types_builder/src/codegen/rust.rs
+++ b/crates/re_types_builder/src/codegen/rust.rs
@@ -18,7 +18,6 @@ use crate::{
 
 // ---
 
-// TODO(cmc): find a way to extract attr name constants directly from the IDL definitions
 pub const ATTR_DERIVE: &str = "rust.attr.derive";
 pub const ATTR_REPR: &str = "rust.attr.repr";
 pub const ATTR_TUPLE_STRUCT: &str = "rust.attr.tuple_struct";
@@ -149,7 +148,7 @@ fn quote_objects(
         for module in mods.keys() {
             code.push_str(&format!("mod {module};\n"));
 
-            // NOTE: detect if someone manually created an extension file, and automatically
+            // Detect if someone manually created an extension file, and automatically
             // import it if so.
             let mut ext_path = out_path.join(format!("{module}_ext"));
             ext_path.set_extension("rs");
@@ -230,7 +229,7 @@ impl QuotedObject {
                 typ: _,
                 attrs: _,
                 required,
-                // TODO(cmc): support for deprecation notices
+                // TODO(#2366): support for deprecation notices
                 deprecated: _,
             } = field;
 
@@ -356,7 +355,8 @@ fn quote_doc_from_docs(docs: &Docs) -> String {
 /// Returns type name as string and whether it was force unwrapped.
 fn quote_field_type_from_field(field: &ObjectField, unwrap: bool) -> (String, bool) {
     let mut unwrapped = false;
-    let typ = match &field.typ {
+    let typ = &field.typ;
+    let typ = match typ {
         Type::UInt8 => "u8".to_owned(),
         Type::UInt16 => "u16".to_owned(),
         Type::UInt32 => "u32".to_owned(),
@@ -366,10 +366,9 @@ fn quote_field_type_from_field(field: &ObjectField, unwrap: bool) -> (String, bo
         Type::Int32 => "i32".to_owned(),
         Type::Int64 => "i64".to_owned(),
         Type::Bool => "bool".to_owned(),
-        Type::Float16 => unimplemented!("ResolvedType::Float16"), // NOLINT
+        Type::Float16 => unimplemented!("{typ:#?}"), // NOLINT
         Type::Float32 => "f32".to_owned(),
         Type::Float64 => "f64".to_owned(),
-        // TODO(cmc): ref for deserialization?
         Type::String => "String".to_owned(),
         Type::Array { elem_type, length } => {
             let typ = quote_type_from_element_type(elem_type);
@@ -406,10 +405,9 @@ fn quote_type_from_element_type(typ: &ElementType) -> String {
         ElementType::Int32 => "i32".to_owned(),
         ElementType::Int64 => "i64".to_owned(),
         ElementType::Bool => "bool".to_owned(),
-        ElementType::Float16 => unimplemented!("ResolvedType::Float16"), // NOLINT
+        ElementType::Float16 => unimplemented!("{typ:#?}"), // NOLINT
         ElementType::Float32 => "f32".to_owned(),
         ElementType::Float64 => "f64".to_owned(),
-        // TODO(cmc): ref for deserialization?
         ElementType::String => "String".to_owned(),
         ElementType::Object(fqname) => fqname.replace('.', "::").replace("rerun", "crate"),
     }
@@ -536,6 +534,7 @@ fn quote_trait_impls_from_obj(arrow_registry: &ArrowRegistry, obj: &Object) -> S
 
                     #[allow(clippy::unimplemented)]
                     fn to_arrow_datatypes() -> Vec<arrow2::datatypes::DataType> {{
+                        // TODO(#2368): dump the arrow registry into the generated code
                         unimplemented!("query the registry for all fqnames"); // NOLINT
                     }}
                 }}
diff --git a/crates/re_types_builder/src/lib.rs b/crates/re_types_builder/src/lib.rs
index b15e3704e1b0..23ee304525b7 100644
--- a/crates/re_types_builder/src/lib.rs
+++ b/crates/re_types_builder/src/lib.rs
@@ -61,6 +61,8 @@
 //!
 //! Make sure to test the behavior of its output though: `re_types`!
 
+// TODO(#2365): support for external IDL definitions
+
 // ---
 
 // NOTE: Official generated code from flatbuffers; ignore _everything_.
@@ -146,7 +148,6 @@ pub fn compile_binary_schemas(
 /// - `include_dir_path`: path to the root directory of the fbs definition tree.
 /// - `output_crate_path`: path to the root of the output crate.
 /// - `entrypoint_path`: path to the root file of the fbs definition tree.
-/// - `source_hash`: optional sha256 hash of the source definition files.
 ///
 /// E.g.:
 /// ```no_run
diff --git a/crates/re_types_builder/src/objects.rs b/crates/re_types_builder/src/objects.rs
index 4f6168c9667d..343e40583ed1 100644
--- a/crates/re_types_builder/src/objects.rs
+++ b/crates/re_types_builder/src/objects.rs
@@ -124,6 +124,22 @@ pub enum ObjectKind {
     Archetype,
 }
 
+impl ObjectKind {
+    // TODO(#2364): use an attr instead of the path
+    pub fn from_pkg_name(pkg_name: impl AsRef<str>) -> Self {
+        let pkg_name = pkg_name.as_ref();
+        if pkg_name.starts_with("rerun.datatypes") {
+            ObjectKind::Datatype
+        } else if pkg_name.starts_with("rerun.components") {
+            ObjectKind::Component
+        } else if pkg_name.starts_with("rerun.archetypes") {
+            ObjectKind::Archetype
+        } else {
+            panic!("unknown package {pkg_name:?}");
+        }
+    }
+}
+
 /// A high-level representation of a flatbuffers object's documentation.
 #[derive(Debug, Clone)]
 pub struct Docs {
@@ -256,18 +272,7 @@ impl Object {
             .unwrap();
 
         let docs = Docs::from_raw_docs(obj.documentation());
-
-        let kind = if pkg_name.starts_with("rerun.datatypes") {
-            ObjectKind::Datatype
-        } else if pkg_name.starts_with("rerun.components") {
-            ObjectKind::Component
-        } else if pkg_name.starts_with("rerun.archetypes") {
-            ObjectKind::Archetype
-        } else {
-            // TODO(cmc): support IDL definitions from outside the repo
-            panic!("unknown package {pkg_name:?}");
-        };
-
+        let kind = ObjectKind::from_pkg_name(&pkg_name);
         let attrs = Attributes::from_raw_attrs(obj.attributes());
 
         let fields = {
@@ -312,17 +317,7 @@ impl Object {
             .unwrap();
 
         let docs = Docs::from_raw_docs(enm.documentation());
-
-        let kind = if pkg_name.starts_with("rerun.datatypes") {
-            ObjectKind::Datatype
-        } else if pkg_name.starts_with("rerun.components") {
-            ObjectKind::Component
-        } else if pkg_name.starts_with("rerun.archetypes") {
-            ObjectKind::Archetype
-        } else {
-            // TODO(cmc): support IDL definitions from outside the repo
-            panic!("unknown package {pkg_name:?}");
-        };
+        let kind = ObjectKind::from_pkg_name(&pkg_name);
 
         let utype = {
             if enm.underlying_type().base_type() == FbsBaseType::UType {
@@ -453,7 +448,8 @@ pub struct ObjectField {
 
     /// Whether the field is deprecated.
     //
-    // TODO(cmc): implement custom attr to specify deprecation reason
+    // TODO(#2366): do something with this
+    // TODO(#2367): implement custom attr to specify deprecation reason
     pub deprecated: bool,
 }
 
@@ -570,7 +566,7 @@ impl ObjectField {
     }
 }
 
-/// The underlying type of a `ResolvedObjectField`.
+/// The underlying type of an [`ObjectField`].
 #[derive(Debug, Clone)]
 pub enum Type {
     UInt8,
@@ -596,24 +592,35 @@ pub enum Type {
     Object(String), // fqname
 }
 
+impl From<ElementType> for Type {
+    fn from(typ: ElementType) -> Self {
+        match typ {
+            ElementType::UInt8 => Self::UInt8,
+            ElementType::UInt16 => Self::UInt16,
+            ElementType::UInt32 => Self::UInt32,
+            ElementType::UInt64 => Self::UInt64,
+            ElementType::Int8 => Self::Int8,
+            ElementType::Int16 => Self::Int16,
+            ElementType::Int32 => Self::Int32,
+            ElementType::Int64 => Self::Int64,
+            ElementType::Bool => Self::Bool,
+            ElementType::Float16 => Self::Float16,
+            ElementType::Float32 => Self::Float32,
+            ElementType::Float64 => Self::Float64,
+            ElementType::String => Self::String,
+            ElementType::Object(fqname) => Self::Object(fqname),
+        }
+    }
+}
+
 impl Type {
     pub fn from_raw_type(
         enums: &[FbsEnum<'_>],
         objs: &[FbsObject<'_>],
         field_type: FbsType<'_>,
     ) -> Self {
-        fn flatten_scalar_wrappers(obj: &FbsObject<'_>) -> Type {
-            if obj.name().starts_with("fbs.scalars.") {
-                match obj.name() {
-                    "fbs.scalars.Float32" => Type::Float32,
-                    _ => unimplemented!(), // NOLINT
-                }
-            } else {
-                Type::Object(obj.name().to_owned())
-            }
-        }
-
-        match field_type.base_type() {
+        let typ = field_type.base_type();
+        match typ {
             FbsBaseType::Bool => Self::Bool,
             FbsBaseType::Byte => Self::Int8,
             FbsBaseType::UByte => Self::UInt8,
@@ -629,7 +636,7 @@ impl Type {
             FbsBaseType::String => Self::String,
             FbsBaseType::Obj => {
                 let obj = &objs[field_type.index() as usize];
-                flatten_scalar_wrappers(obj)
+                flatten_scalar_wrappers(obj).into()
             }
             FbsBaseType::Union => {
                 let union = &enums[field_type.index() as usize];
@@ -654,10 +661,11 @@ impl Type {
                     field_type.element(),
                 ),
             },
-            FbsBaseType::None => unimplemented!(),  // NOLINT
-            FbsBaseType::UType => unimplemented!(), // NOLINT
-            FbsBaseType::Vector64 => unimplemented!(), // NOLINT
-            _ => unreachable!(),
+            FbsBaseType::None | FbsBaseType::UType | FbsBaseType::Vector64 => {
+                unimplemented!("{typ:#?}") // NOLINT
+            } // NOLINT
+            // NOTE: `FbsBaseType` isn't actually an enum, it's just a bunch of constants...
+            _ => unreachable!("{typ:#?}"),
         }
     }
 }
@@ -691,18 +699,7 @@ impl ElementType {
         outer_type: FbsType<'_>,
         inner_type: FbsBaseType,
     ) -> Self {
-        /// Helper to turn wrapped scalars into actual scalars.
-        fn flatten_scalar_wrappers(obj: &FbsObject<'_>) -> ElementType {
-            if obj.name().starts_with("fbs.scalars.") {
-                match obj.name() {
-                    "fbs.scalars.Float32" => ElementType::Float32,
-                    _ => unimplemented!(), // NOLINT
-                }
-            } else {
-                ElementType::Object(obj.name().to_owned())
-            }
-        }
-
+        #[allow(clippy::match_same_arms)]
         match inner_type {
             FbsBaseType::Bool => Self::Bool,
             FbsBaseType::Byte => Self::Int8,
@@ -713,7 +710,6 @@ impl ElementType {
             FbsBaseType::UInt => Self::UInt32,
             FbsBaseType::Long => Self::Int64,
             FbsBaseType::ULong => Self::UInt64,
-            // TODO(cmc): half support
             FbsBaseType::Float => Self::Float32,
             FbsBaseType::Double => Self::Float64,
             FbsBaseType::String => Self::String,
@@ -721,15 +717,16 @@ impl ElementType {
                 let obj = &objs[outer_type.index() as usize];
                 flatten_scalar_wrappers(obj)
             }
-            FbsBaseType::Union => unimplemented!(), // NOLINT
+            FbsBaseType::Union => unimplemented!("{inner_type:#?}"), // NOLINT
             // NOTE: flatbuffers doesn't support directly nesting multiple layers of arrays, they
             // always have to be wrapped into intermediate layers of structs or tables.
-            FbsBaseType::Array => unimplemented!(),  // NOLINT
-            FbsBaseType::None => unimplemented!(),   // NOLINT
-            FbsBaseType::UType => unimplemented!(),  // NOLINT
-            FbsBaseType::Vector => unimplemented!(), // NOLINT
-            FbsBaseType::Vector64 => unimplemented!(), // NOLINT
-            _ => unreachable!(),
+            FbsBaseType::None
+            | FbsBaseType::UType
+            | FbsBaseType::Array
+            | FbsBaseType::Vector
+            | FbsBaseType::Vector64 => unreachable!("{inner_type:#?}"),
+            // NOTE: `FbsType` isn't actually an enum, it's just a bunch of constants...
+            _ => unreachable!("{inner_type:#?}"),
         }
     }
 }
@@ -777,9 +774,10 @@ impl Attributes {
         value_str
             .parse()
             .with_context(|| {
+                let type_of_t = std::any::type_name::<T>();
                 format!(
                     "invalid `{name}` attribute for `{owner_fqname}`: \
-                    expected unsigned integer, got `{value_str}` instead"
+                    expected {type_of_t}, got `{value_str}` instead"
                 )
             })
             .unwrap()
@@ -803,12 +801,26 @@ impl Attributes {
             value_str
                 .parse()
                 .with_context(|| {
+                    let type_of_t = std::any::type_name::<T>();
                     format!(
                         "invalid `{name}` attribute for `{owner_fqname}`: \
-                        expected unsigned integer, got `{value_str}` instead"
+                        expected {type_of_t}, got `{value_str}` instead"
                     )
                 })
                 .unwrap(),
         )
     }
 }
+
+/// Helper to turn wrapped scalars into actual scalars.
+fn flatten_scalar_wrappers(obj: &FbsObject<'_>) -> ElementType {
+    let name = obj.name();
+    if name.starts_with("fbs.scalars.") {
+        match name {
+            "fbs.scalars.Float32" => ElementType::Float32,
+            _ => unimplemented!("{name:#?}"), // NOLINT
+        }
+    } else {
+        ElementType::Object(name.to_owned())
+    }
+}

From fb1d9e6d93cc13de9aefc16023b78b4a5f59f181 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Mon, 12 Jun 2023 11:13:24 +0200
Subject: [PATCH 08/18] adhering to py38+ style guide

---
 crates/re_types_builder/src/codegen/python.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/crates/re_types_builder/src/codegen/python.rs b/crates/re_types_builder/src/codegen/python.rs
index 2cba90d0a457..4d06dcc60e86 100644
--- a/crates/re_types_builder/src/codegen/python.rs
+++ b/crates/re_types_builder/src/codegen/python.rs
@@ -294,7 +294,7 @@ impl QuotedObject {
             let typ = if field.required {
                 typ
             } else {
-                format!("Optional[{typ}] = None")
+                format!("{typ} | None = None")
             };
 
             code.push_str(&indent::indent_all_by(4, format!("{name}: {typ}\n")));
@@ -397,7 +397,7 @@ impl QuotedObject {
             // NOTE: It's always optional since only one of the fields can be set at a time.
             code.push_str(&indent::indent_all_by(
                 4,
-                format!("{name}: Optional[{typ}] = None\n"),
+                format!("{name}: {typ} | None = None\n"),
             ));
 
             code.push_str(&indent::indent_all_by(4, quote_doc_from_docs(docs)));
@@ -794,7 +794,7 @@ fn quote_arrow_support_from_obj(arrow_registry: &ArrowRegistry, obj: &Object) ->
 
                 class {many}(pa.ExtensionArray, {many}Ext):  # type: ignore[misc]
                     @staticmethod
-                    def from_similar(data: Optional[{many_aliases}]):
+                    def from_similar(data: {many_aliases} | None):
                         if data is None:
                             return {arrow}().wrap_array(pa.array([], type={arrow}().storage_type))
                         else:
@@ -849,9 +849,9 @@ fn quote_builder_from_obj(objects: &Objects, obj: &Object) -> String {
             let (typ, unwrapped) = quote_field_type_from_field(objects, field, true);
             if unwrapped {
                 // This was originally a vec/array!
-                format!("{}: Optional[{typ}ArrayLike] = None", field.name)
+                format!("{}: {typ}ArrayLike | None = None", field.name)
             } else {
-                format!("{}: Optional[{typ}Like] = None", field.name)
+                format!("{}: {typ}Like | None = None", field.name)
             }
         })
         .collect::<Vec<_>>()

From d8c094e1fc31813100d2c9affa8a860716c42e85 Mon Sep 17 00:00:00 2001
From: Andreas Reich <r_andreas2@web.de>
Date: Mon, 12 Jun 2023 17:25:01 +0200
Subject: [PATCH 09/18] vscode flatbuffer things. Fix comment typo

---
 crates/re_types_builder/src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/re_types_builder/src/lib.rs b/crates/re_types_builder/src/lib.rs
index 23ee304525b7..436126e7b885 100644
--- a/crates/re_types_builder/src/lib.rs
+++ b/crates/re_types_builder/src/lib.rs
@@ -18,7 +18,7 @@
 //! ####. 2. Run the semantic pass.
 //!
 //! The semantic pass transforms the low-level raw reflection data generated by the first phase
-//! into higher level objects that are much easier to inspect/manipulate and overall friendler
+//! into higher level objects that are much easier to inspect/manipulate and overall friendlier
 //! to work with.
 //!
 //! Look for `objects.rs`.

From 7ae14c3d5cb990c9a04b49ba962c4438211ba00e Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Tue, 13 Jun 2023 10:13:30 +0200
Subject: [PATCH 10/18] turn the inner from_similar into _from_similar to
 appease linters

---
 crates/re_types_builder/src/codegen/python.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/re_types_builder/src/codegen/python.rs b/crates/re_types_builder/src/codegen/python.rs
index 4d06dcc60e86..548c5ebfebd0 100644
--- a/crates/re_types_builder/src/codegen/python.rs
+++ b/crates/re_types_builder/src/codegen/python.rs
@@ -798,7 +798,7 @@ fn quote_arrow_support_from_obj(arrow_registry: &ArrowRegistry, obj: &Object) ->
                         if data is None:
                             return {arrow}().wrap_array(pa.array([], type={arrow}().storage_type))
                         else:
-                            return {many}Ext.from_similar(
+                            return {many}Ext._from_similar(
                                 data,
                                 mono={mono},
                                 mono_aliases={mono_aliases},

From 0bc204cba4d83d288056d30fb6b462d1d73130c4 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Tue, 13 Jun 2023 11:21:13 +0200
Subject: [PATCH 11/18] generate __all__ everywhere to make python tools behave

---
 crates/re_types_builder/src/codegen/python.rs | 66 ++++++++++++++-----
 1 file changed, 49 insertions(+), 17 deletions(-)

diff --git a/crates/re_types_builder/src/codegen/python.rs b/crates/re_types_builder/src/codegen/python.rs
index 548c5ebfebd0..9c4bb20f72d4 100644
--- a/crates/re_types_builder/src/codegen/python.rs
+++ b/crates/re_types_builder/src/codegen/python.rs
@@ -93,17 +93,24 @@ fn quote_lib(out_path: impl AsRef<Path>, archetype_names: &[String]) -> PathBuf
         .unwrap();
 
     let path = out_path.join("__init__.py");
+    let all_names = archetype_names
+        .iter()
+        .map(|name| format!("{name:?}"))
+        .collect::<Vec<_>>()
+        .join(", ");
     let archetype_names = archetype_names.join(", ");
 
     let mut code = String::new();
 
-    // NOTE: noqa F401 (unused import) because while unnecessary these listings are
-    // very useful to look at.
     code += &unindent::unindent(&format!(
         r#"
         # {AUTOGEN_WARNING}
 
-        from .archetypes import {archetype_names} # noqa: F401
+        from __future__ import annotations
+
+        __all__ = [{all_names}]
+
+        from .archetypes import {archetype_names}
         "#
     ));
 
@@ -154,12 +161,19 @@ fn quote_objects(
     for (filepath, objs) in files {
         let names = objs
             .iter()
-            .map(|obj| match obj.kind {
+            .flat_map(|obj| match obj.kind {
                 ObjectKind::Datatype | ObjectKind::Component => {
                     let name = &obj.name;
-                    format!("{name}, {name}Like, {name}Array, {name}ArrayLike, {name}Type")
+
+                    vec![
+                        format!("{name}"),
+                        format!("{name}Like"),
+                        format!("{name}Array"),
+                        format!("{name}ArrayLike"),
+                        format!("{name}Type"),
+                    ]
                 }
-                ObjectKind::Archetype => obj.name.clone(),
+                ObjectKind::Archetype => vec![obj.name.clone()],
             })
             .collect::<Vec<_>>();
 
@@ -167,10 +181,10 @@ fn quote_objects(
         // and archetypes separately (and even then it's a bit shady, eh).
         match mods.entry(filepath.file_stem().unwrap().to_string_lossy().to_string()) {
             std::collections::hash_map::Entry::Occupied(mut entry) => {
-                entry.get_mut().extend(names);
+                entry.get_mut().extend(names.iter().cloned());
             }
             std::collections::hash_map::Entry::Vacant(entry) => {
-                entry.insert(names);
+                entry.insert(names.clone());
             }
         };
 
@@ -182,6 +196,20 @@ fn quote_objects(
         let mut code = String::new();
         code.push_str(&format!("# {AUTOGEN_WARNING}\n\n"));
 
+        let names = names
+            .into_iter()
+            .map(|name| format!("{name:?}"))
+            .collect::<Vec<_>>()
+            .join(", ");
+        code.push_str(&unindent::unindent(&format!(
+            "
+            from __future__ import annotations
+
+            __all__ = [{names}]
+
+            ",
+        )));
+
         for obj in objs {
             code.push_str(&obj.code);
             code.push('\n');
@@ -197,20 +225,26 @@ fn quote_objects(
 
         let mut code = String::new();
 
+        let all_names = mods
+            .iter()
+            .flat_map(|(_, names)| names.iter().map(|name| format!("{name:?}")))
+            .collect::<Vec<_>>()
+            .join(", ");
+
         code.push_str(&format!("# {AUTOGEN_WARNING}\n\n"));
-        code.push_str(&unindent::unindent(
+        code.push_str(&unindent::unindent(&format!(
             "
-            # NOTE:
-            # - we use fully qualified paths to prevent lazy circular imports
-            # - `noqa F401` (unused import) everywhere because, while not strictly necessary,
-            #   these imports are very nice for end users.
+            from __future__ import annotations
 
+            __all__ = [{all_names}]
+
+            # NOTE: we use fully qualified paths to prevent lazy circular imports.
             ",
-        ));
+        )));
 
         for (module, names) in &mods {
             let names = names.join(", ");
-            code.push_str(&format!("from .{module} import {names} # noqa: F401\n"));
+            code.push_str(&format!("from .{module} import {names}\n"));
         }
 
         filepaths.push(path.clone());
@@ -442,8 +476,6 @@ fn quote_module_prelude() -> String {
     // NOTE: All the extraneous stuff will be cleaned up courtesy of `ruff`.
     unindent::unindent(
         r#"
-        from __future__ import annotations
-
         import numpy as np
         import numpy.typing as npt
         import pyarrow as pa

From 6db76c76be8da6180c1f2bc7516814359fb8cf64 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Tue, 13 Jun 2023 12:21:49 +0200
Subject: [PATCH 12/18] make sure __all__ manifests are lexically sorted

---
 crates/re_types_builder/src/codegen/python.rs | 34 +++++++++----------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/crates/re_types_builder/src/codegen/python.rs b/crates/re_types_builder/src/codegen/python.rs
index 9c4bb20f72d4..78f5c1e9cf93 100644
--- a/crates/re_types_builder/src/codegen/python.rs
+++ b/crates/re_types_builder/src/codegen/python.rs
@@ -93,11 +93,7 @@ fn quote_lib(out_path: impl AsRef<Path>, archetype_names: &[String]) -> PathBuf
         .unwrap();
 
     let path = out_path.join("__init__.py");
-    let all_names = archetype_names
-        .iter()
-        .map(|name| format!("{name:?}"))
-        .collect::<Vec<_>>()
-        .join(", ");
+    let manifest = quote_manifest(archetype_names);
     let archetype_names = archetype_names.join(", ");
 
     let mut code = String::new();
@@ -108,7 +104,7 @@ fn quote_lib(out_path: impl AsRef<Path>, archetype_names: &[String]) -> PathBuf
 
         from __future__ import annotations
 
-        __all__ = [{all_names}]
+        __all__ = [{manifest}]
 
         from .archetypes import {archetype_names}
         "#
@@ -196,16 +192,12 @@ fn quote_objects(
         let mut code = String::new();
         code.push_str(&format!("# {AUTOGEN_WARNING}\n\n"));
 
-        let names = names
-            .into_iter()
-            .map(|name| format!("{name:?}"))
-            .collect::<Vec<_>>()
-            .join(", ");
+        let manifest = quote_manifest(names);
         code.push_str(&unindent::unindent(&format!(
             "
             from __future__ import annotations
 
-            __all__ = [{names}]
+            __all__ = [{manifest}]
 
             ",
         )));
@@ -225,18 +217,14 @@ fn quote_objects(
 
         let mut code = String::new();
 
-        let all_names = mods
-            .iter()
-            .flat_map(|(_, names)| names.iter().map(|name| format!("{name:?}")))
-            .collect::<Vec<_>>()
-            .join(", ");
+        let manifest = quote_manifest(mods.iter().flat_map(|(_, names)| names.iter()));
 
         code.push_str(&format!("# {AUTOGEN_WARNING}\n\n"));
         code.push_str(&unindent::unindent(&format!(
             "
             from __future__ import annotations
 
-            __all__ = [{all_names}]
+            __all__ = [{manifest}]
 
             # NOTE: we use fully qualified paths to prevent lazy circular imports.
             ",
@@ -472,6 +460,16 @@ impl QuotedObject {
 
 // --- Code generators ---
 
+fn quote_manifest(names: impl IntoIterator<Item = impl AsRef<str>>) -> String {
+    let mut quoted_names: Vec<_> = names
+        .into_iter()
+        .map(|name| format!("{:?}", name.as_ref()))
+        .collect();
+    quoted_names.sort();
+
+    quoted_names.join(", ")
+}
+
 fn quote_module_prelude() -> String {
     // NOTE: All the extraneous stuff will be cleaned up courtesy of `ruff`.
     unindent::unindent(

From 8d69d7ebc42cbccc1aaee82854256bb9a1c0674f Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Wed, 14 Jun 2023 10:49:25 +0200
Subject: [PATCH 13/18] adressing PR comments

---
 crates/re_types_builder/build.rs              |  14 +-
 .../definitions/reflection.fbs                |   3 +
 crates/re_types_builder/source_hash.txt       |   2 +-
 crates/re_types_builder/src/arrow_registry.rs |   9 +-
 crates/re_types_builder/src/codegen/common.rs |  19 ++
 crates/re_types_builder/src/codegen/mod.rs    |   6 +-
 crates/re_types_builder/src/codegen/python.rs | 264 ++++++++----------
 crates/re_types_builder/src/codegen/rust.rs   | 142 +++++-----
 crates/re_types_builder/src/lib.rs            |  99 ++++---
 crates/re_types_builder/src/objects.rs        |   6 +-
 10 files changed, 274 insertions(+), 290 deletions(-)

diff --git a/crates/re_types_builder/build.rs b/crates/re_types_builder/build.rs
index 5c949bf4f298..bac5e2d4deb6 100644
--- a/crates/re_types_builder/build.rs
+++ b/crates/re_types_builder/build.rs
@@ -3,8 +3,7 @@
 use xshell::{cmd, Shell};
 
 use re_build_tools::{
-    compute_file_hash, is_tracked_env_var_set, read_versioning_hash, rerun_if_changed,
-    rerun_if_changed_or_doesnt_exist, write_versioning_hash,
+    compute_file_hash, is_tracked_env_var_set, read_versioning_hash, write_versioning_hash,
 };
 
 // ---
@@ -33,9 +32,14 @@ fn main() {
         return;
     }
 
-    rerun_if_changed_or_doesnt_exist(SOURCE_HASH_PATH);
-    rerun_if_changed(FBS_REFLECTION_DEFINITION_PATH);
-
+    // We're building an actual build graph here, and Cargo has no idea about it.
+    //
+    // Worse: some nodes in our build graph actually output artifacts into the src/ directory,
+    // which Cargo always interprets as "need to rebuild everything ASAP", leading to an infinite
+    // feedback loop.
+    //
+    // For these reasons, we manually compute and track signature hashes for the graph nodes we
+    // depend on, and make sure to exit early if everything's already up to date.
     let cur_hash = read_versioning_hash(SOURCE_HASH_PATH);
     let new_hash = compute_file_hash(FBS_REFLECTION_DEFINITION_PATH);
 
diff --git a/crates/re_types_builder/definitions/reflection.fbs b/crates/re_types_builder/definitions/reflection.fbs
index 513311f1b9c3..cf6cb9e3c4e4 100644
--- a/crates/re_types_builder/definitions/reflection.fbs
+++ b/crates/re_types_builder/definitions/reflection.fbs
@@ -1,3 +1,6 @@
+// Copied verbatim from the official flatbuffers source tree:
+// https://github.com/google/flatbuffers/blob/63b7b25289447313ab6e79191fa1733748dca0da/reflection/reflection.fbs
+
 // This schema defines objects that represent a parsed schema, like
 // the binary version of a .fbs file.
 // This could be used to operate on unknown FlatBuffers at runtime.
diff --git a/crates/re_types_builder/source_hash.txt b/crates/re_types_builder/source_hash.txt
index f1766f06bb26..2d51980aefb3 100644
--- a/crates/re_types_builder/source_hash.txt
+++ b/crates/re_types_builder/source_hash.txt
@@ -1,4 +1,4 @@
 # This is a sha256 hash for all direct and indirect dependencies of this crate's build script.
 # It can be safely removed at anytime to force the build script to run again.
 # Check out build.rs to see how it's computed.
-72d936d50287d6c16d0c1b91f86bd74120642c8fc08e885f08dd2b92bb52e8a4
\ No newline at end of file
+674450e64722effea9b29a84c34fab81b9d57497136a8f161561b8e19f7441b2
\ No newline at end of file
diff --git a/crates/re_types_builder/src/arrow_registry.rs b/crates/re_types_builder/src/arrow_registry.rs
index e0edc01cddf5..505d0ccd253a 100644
--- a/crates/re_types_builder/src/arrow_registry.rs
+++ b/crates/re_types_builder/src/arrow_registry.rs
@@ -4,12 +4,7 @@ use anyhow::Context as _;
 use arrow2::datatypes::{DataType, Field, UnionMode};
 use std::collections::{BTreeMap, HashMap};
 
-use crate::{ElementType, Object, Type};
-
-// ---
-
-pub const ARROW_ATTR_TRANSPARENT: &str = "arrow.attr.transparent";
-pub const ARROW_ATTR_SPARSE_UNION: &str = "arrow.attr.sparse_union";
+use crate::{ElementType, Object, Type, ARROW_ATTR_SPARSE_UNION, ARROW_ATTR_TRANSPARENT};
 
 // --- Registry ---
 
@@ -59,7 +54,7 @@ impl ArrowRegistry {
         let num_fields = obj.fields.len();
 
         assert!(
-            !(is_transparent && (!is_struct || num_fields != 1)),
+            !is_transparent || (is_struct && num_fields == 1),
             "cannot have a transparent arrow object with any number of fields but 1: {:?} has {num_fields}",
             obj.fqname,
         );
diff --git a/crates/re_types_builder/src/codegen/common.rs b/crates/re_types_builder/src/codegen/common.rs
index 4317b76c481c..d0bd52a5716c 100644
--- a/crates/re_types_builder/src/codegen/common.rs
+++ b/crates/re_types_builder/src/codegen/common.rs
@@ -39,3 +39,22 @@ pub fn quote_doc_from_docs(docs: &Docs, tags: &[&str]) -> Vec<String> {
 
     lines
 }
+
+pub trait StringExt {
+    fn push_text(&mut self, text: impl AsRef<str>, linefeeds: usize, indent: usize) -> &mut Self;
+    fn push_unindented_text(&mut self, text: impl AsRef<str>, linefeeds: usize) -> &mut Self;
+}
+
+impl StringExt for String {
+    fn push_text(&mut self, text: impl AsRef<str>, linefeeds: usize, indent: usize) -> &mut Self {
+        self.push_str(&indent::indent_all_by(indent, text.as_ref()));
+        self.push_str(&vec!["\n"; linefeeds].join(""));
+        self
+    }
+
+    fn push_unindented_text(&mut self, text: impl AsRef<str>, linefeeds: usize) -> &mut Self {
+        self.push_str(&unindent::unindent(text.as_ref()));
+        self.push_str(&vec!["\n"; linefeeds].join(""));
+        self
+    }
+}
diff --git a/crates/re_types_builder/src/codegen/mod.rs b/crates/re_types_builder/src/codegen/mod.rs
index eb2e4d553265..240fabd14e9a 100644
--- a/crates/re_types_builder/src/codegen/mod.rs
+++ b/crates/re_types_builder/src/codegen/mod.rs
@@ -15,14 +15,10 @@ pub trait CodeGenerator {
 pub const AUTOGEN_WARNING: &str =
     "NOTE: This file was autogenerated by re_types_builder; DO NOT EDIT.";
 
-pub const RERUN_ATTR_COMPONENT_REQUIRED: &str = "rerun.attr.component_required";
-pub const RERUN_ATTR_COMPONENT_RECOMMENDED: &str = "rerun.attr.component_recommended";
-pub const RERUN_ATTR_COMPONENT_OPTIONAL: &str = "rerun.attr.component_optional";
-
 // ---
 
 mod common;
-use self::common::quote_doc_from_docs;
+use self::common::{quote_doc_from_docs, StringExt};
 
 mod python;
 mod rust;
diff --git a/crates/re_types_builder/src/codegen/python.rs b/crates/re_types_builder/src/codegen/python.rs
index 78f5c1e9cf93..a695cbee5970 100644
--- a/crates/re_types_builder/src/codegen/python.rs
+++ b/crates/re_types_builder/src/codegen/python.rs
@@ -8,8 +8,9 @@ use std::{
 };
 
 use crate::{
-    codegen::AUTOGEN_WARNING, ArrowRegistry, CodeGenerator, Docs, ElementType, Object, ObjectField,
-    ObjectKind, Objects, Type,
+    codegen::{StringExt as _, AUTOGEN_WARNING},
+    ArrowRegistry, CodeGenerator, Docs, ElementType, Object, ObjectField, ObjectKind, Objects,
+    Type, PYTHON_ATTR_ALIASES, PYTHON_ATTR_ARRAY_ALIASES, PYTHON_ATTR_TRANSPARENT,
 };
 
 // ---
@@ -17,10 +18,6 @@ use crate::{
 // NOTE: `rerun2` while we figure out how to integrate back into the main SDK.
 const MODULE_NAME: &str = "rerun2";
 
-pub const ATTR_TRANSPARENT: &str = "python.attr.transparent";
-pub const ATTR_ALIASES: &str = "python.attr.aliases";
-pub const ATTR_ARRAY_ALIASES: &str = "python.attr.array_aliases";
-
 pub struct PythonCodeGenerator {
     pkg_path: PathBuf,
 }
@@ -138,16 +135,9 @@ fn quote_objects(
         } else {
             QuotedObject::from_union(arrow_registry, all_objects, obj)
         };
-        let filepath = out_path.join(obj.filepath.file_name().unwrap());
 
-        match files.entry(filepath.clone()) {
-            std::collections::hash_map::Entry::Occupied(mut entry) => {
-                entry.get_mut().push(obj);
-            }
-            std::collections::hash_map::Entry::Vacant(entry) => {
-                entry.insert(vec![obj]);
-            }
-        };
+        let filepath = out_path.join(obj.filepath.file_name().unwrap());
+        files.entry(filepath.clone()).or_default().push(obj);
     }
 
     // (module_name, [object_name])
@@ -175,14 +165,9 @@ fn quote_objects(
 
         // NOTE: Isolating the file stem only works because we're handling datatypes, components
         // and archetypes separately (and even then it's a bit shady, eh).
-        match mods.entry(filepath.file_stem().unwrap().to_string_lossy().to_string()) {
-            std::collections::hash_map::Entry::Occupied(mut entry) => {
-                entry.get_mut().extend(names.iter().cloned());
-            }
-            std::collections::hash_map::Entry::Vacant(entry) => {
-                entry.insert(names.clone());
-            }
-        };
+        mods.entry(filepath.file_stem().unwrap().to_string_lossy().to_string())
+            .or_default()
+            .extend(names.iter().cloned());
 
         filepaths.push(filepath.clone());
         let mut file = std::fs::File::create(&filepath)
@@ -190,21 +175,23 @@ fn quote_objects(
             .unwrap();
 
         let mut code = String::new();
-        code.push_str(&format!("# {AUTOGEN_WARNING}\n\n"));
+        code.push_text(&format!("# {AUTOGEN_WARNING}"), 2, 0);
 
         let manifest = quote_manifest(names);
-        code.push_str(&unindent::unindent(&format!(
-            "
-            from __future__ import annotations
+        code.push_unindented_text(
+            format!(
+                "
+                from __future__ import annotations
 
-            __all__ = [{manifest}]
+                __all__ = [{manifest}]
 
-            ",
-        )));
+                ",
+            ),
+            0,
+        );
 
         for obj in objs {
-            code.push_str(&obj.code);
-            code.push('\n');
+            code.push_text(&obj.code, 1, 0);
         }
         file.write_all(code.as_bytes())
             .with_context(|| format!("{filepath:?}"))
@@ -219,20 +206,23 @@ fn quote_objects(
 
         let manifest = quote_manifest(mods.iter().flat_map(|(_, names)| names.iter()));
 
-        code.push_str(&format!("# {AUTOGEN_WARNING}\n\n"));
-        code.push_str(&unindent::unindent(&format!(
-            "
-            from __future__ import annotations
+        code.push_text(&format!("# {AUTOGEN_WARNING}"), 2, 0);
+        code.push_unindented_text(
+            format!(
+                "
+                from __future__ import annotations
 
-            __all__ = [{manifest}]
+                __all__ = [{manifest}]
 
-            # NOTE: we use fully qualified paths to prevent lazy circular imports.
-            ",
-        )));
+                # NOTE: we use fully qualified paths to prevent lazy circular imports.
+                ",
+            ),
+            0,
+        );
 
         for (module, names) in &mods {
             let names = names.join(", ");
-            code.push_str(&format!("from .{module} import {names}\n"));
+            code.push_text(&format!("from .{module} import {names}"), 1, 0);
         }
 
         filepaths.push(path.clone());
@@ -272,26 +262,28 @@ impl QuotedObject {
 
         let mut code = String::new();
 
-        code.push_str(&quote_module_prelude());
+        code.push_text(&quote_module_prelude(), 0, 0);
 
         for clause in obj
             .fields
             .iter()
             .filter_map(quote_import_clauses_from_field)
         {
-            code.push_str(&clause);
-            code.push('\n');
+            code.push_text(&clause, 1, 0);
         }
 
-        code.push_str(&unindent::unindent(&format!(
-            r#"
+        code.push_unindented_text(
+            format!(
+                r#"
 
-            @dataclass
-            class {name}:
-            "#
-        )));
+                @dataclass
+                class {name}:
+                "#
+            ),
+            0,
+        );
 
-        code.push_str(&indent::indent_all_by(4, quote_doc_from_docs(docs)));
+        code.push_text(quote_doc_from_docs(docs), 0, 4);
 
         for field in fields {
             let ObjectField {
@@ -319,39 +311,22 @@ impl QuotedObject {
                 format!("{typ} | None = None")
             };
 
-            code.push_str(&indent::indent_all_by(4, format!("{name}: {typ}\n")));
+            code.push_text(format!("{name}: {typ}"), 1, 4);
 
-            code.push_str(&indent::indent_all_by(4, quote_doc_from_docs(docs)));
+            code.push_text(quote_doc_from_docs(docs), 0, 4);
         }
 
-        code.push_str(&indent::indent_all_by(4, quote_str_repr_from_obj(obj)));
-        code.push('\n');
-
-        code.push_str(&indent::indent_all_by(
-            4,
-            quote_array_method_from_obj(objects, obj),
-        ));
-        code.push('\n');
-
-        code.push_str(&indent::indent_all_by(
-            4,
-            quote_str_method_from_obj(objects, obj),
-        ));
-        code.push('\n');
+        code.push_text(quote_str_repr_from_obj(obj), 1, 4);
+        code.push_text(quote_array_method_from_obj(objects, obj), 1, 4);
+        code.push_text(quote_str_method_from_obj(objects, obj), 1, 4);
 
         if obj.kind == ObjectKind::Archetype {
-            code.push_str(&indent::indent_all_by(
-                4,
-                quote_builder_from_obj(objects, obj),
-            ));
-            code.push('\n');
+            code.push_text(quote_builder_from_obj(objects, obj), 1, 4);
         } else {
-            code.push_str(&quote_aliases_from_object(obj));
-            code.push('\n');
+            code.push_text(quote_aliases_from_object(obj), 1, 4);
         }
 
-        code.push_str(&quote_arrow_support_from_obj(arrow_registry, obj));
-        code.push('\n');
+        code.push_text(quote_arrow_support_from_obj(arrow_registry, obj), 1, 4);
 
         let mut filepath = PathBuf::from(filepath);
         filepath.set_extension("py");
@@ -381,26 +356,28 @@ impl QuotedObject {
 
         let mut code = String::new();
 
-        code.push_str(&quote_module_prelude());
+        code.push_text(&quote_module_prelude(), 0, 0);
 
         for clause in obj
             .fields
             .iter()
             .filter_map(quote_import_clauses_from_field)
         {
-            code.push_str(&clause);
-            code.push('\n');
+            code.push_text(&clause, 1, 0);
         }
 
-        code.push_str(&unindent::unindent(&format!(
-            r#"
+        code.push_unindented_text(
+            format!(
+                r#"
 
-            @dataclass
-            class {name}:
-            "#
-        )));
+                @dataclass
+                class {name}:
+                "#
+            ),
+            0,
+        );
 
-        code.push_str(&indent::indent_all_by(4, quote_doc_from_docs(docs)));
+        code.push_text(quote_doc_from_docs(docs), 0, 4);
 
         for field in fields {
             let ObjectField {
@@ -417,34 +394,16 @@ impl QuotedObject {
 
             let (typ, _) = quote_field_type_from_field(objects, field, false);
             // NOTE: It's always optional since only one of the fields can be set at a time.
-            code.push_str(&indent::indent_all_by(
-                4,
-                format!("{name}: {typ} | None = None\n"),
-            ));
+            code.push_text(format!("{name}: {typ} | None = None"), 1, 4);
 
-            code.push_str(&indent::indent_all_by(4, quote_doc_from_docs(docs)));
+            code.push_text(quote_doc_from_docs(docs), 0, 4);
         }
 
-        code.push_str(&indent::indent_all_by(4, quote_str_repr_from_obj(obj)));
-        code.push('\n');
-
-        code.push_str(&indent::indent_all_by(
-            4,
-            quote_array_method_from_obj(objects, obj),
-        ));
-        code.push('\n');
-
-        code.push_str(&indent::indent_all_by(
-            4,
-            quote_str_method_from_obj(objects, obj),
-        ));
-        code.push('\n');
-
-        code.push_str(&quote_aliases_from_object(obj));
-        code.push('\n');
-
-        code.push_str(&quote_arrow_support_from_obj(arrow_registry, obj));
-        code.push('\n');
+        code.push_text(quote_str_repr_from_obj(obj), 1, 4);
+        code.push_text(quote_array_method_from_obj(objects, obj), 1, 4);
+        code.push_text(quote_str_method_from_obj(objects, obj), 1, 4);
+        code.push_text(quote_aliases_from_object(obj), 1, 4);
+        code.push_text(quote_arrow_support_from_obj(arrow_registry, obj), 1, 4);
 
         let mut filepath = PathBuf::from(filepath);
         filepath.set_extension("py");
@@ -585,38 +544,43 @@ fn quote_str_method_from_obj(objects: &Objects, obj: &Object) -> String {
 fn quote_aliases_from_object(obj: &Object) -> String {
     assert!(obj.kind != ObjectKind::Archetype);
 
-    let aliases = obj.try_get_attr::<String>(ATTR_ALIASES);
+    let aliases = obj.try_get_attr::<String>(PYTHON_ATTR_ALIASES);
     let array_aliases = obj
-        .try_get_attr::<String>(ATTR_ARRAY_ALIASES)
+        .try_get_attr::<String>(PYTHON_ATTR_ARRAY_ALIASES)
         .unwrap_or_default();
 
     let name = &obj.name;
 
     let mut code = String::new();
 
-    code.push_str(&if let Some(aliases) = aliases {
-        unindent::unindent(&format!(
+    code.push_unindented_text(
+        &if let Some(aliases) = aliases {
+            format!(
+                r#"
+                {name}Like = Union[
+                    {name},
+                    {aliases}
+                ]
+                "#,
+            )
+        } else {
+            format!("{name}Like = {name}")
+        },
+        1,
+    );
+
+    code.push_unindented_text(
+        format!(
             r#"
-            {name}Like = Union[
-                {name},
-                {aliases}
+            {name}ArrayLike = Union[
+                {name}Like,
+                Sequence[{name}Like],
+                {array_aliases}
             ]
-
             "#,
-        ))
-    } else {
-        format!("{name}Like = {name}\n")
-    });
-
-    code.push_str(&unindent::unindent(&format!(
-        r#"
-        {name}ArrayLike = Union[
-            {name}Like,
-            Sequence[{name}Like],
-            {array_aliases}
-        ]
-        "#,
-    )));
+        ),
+        0,
+    );
 
     code
 }
@@ -657,6 +621,10 @@ fn quote_import_clauses_from_field(field: &ObjectField) -> Option<String> {
 }
 
 /// Returns type name as string and whether it was force unwrapped.
+///
+/// Specifying `unwrap = true` will unwrap the final type before returning it, e.g. `Vec<String>`
+/// becomes just `String`.
+/// The returned boolean indicates whether there was anything to unwrap at all.
 fn quote_field_type_from_field(
     objects: &Objects,
     field: &ObjectField,
@@ -713,7 +681,9 @@ fn quote_field_type_from_field(
             // TODO(cmc): it is a bit weird to be doing the transparency logic (which is language
             // agnostic) in a python specific quoting function... a static helper at the very least
             // would be nice.
-            let is_transparent = field.try_get_attr::<String>(ATTR_TRANSPARENT).is_some();
+            let is_transparent = field
+                .try_get_attr::<String>(PYTHON_ATTR_TRANSPARENT)
+                .is_some();
             if is_transparent {
                 let target = objects.get(fqname);
                 assert!(
@@ -887,30 +857,34 @@ fn quote_builder_from_obj(objects: &Objects, obj: &Object) -> String {
         .collect::<Vec<_>>()
         .join(", ");
 
-    code.push_str(&format!(
-        "def __init__(self, {required_args}, *, {optional_args}) -> None:\n"
-    ));
+    code.push_text(
+        format!("def __init__(self, {required_args}, *, {optional_args}) -> None:"),
+        1,
+        0,
+    );
 
-    code.push_str(&indent::indent_all_by(4, "# Required components\n"));
+    code.push_text("# Required components", 1, 4);
     for field in required {
         let name = &field.name;
         let (typ, _) = quote_field_type_from_field(objects, field, true);
-        code.push_str(&indent::indent_all_by(
+        code.push_text(
+            format!("self.{name} = {typ}Array.from_similar({name})"),
+            1,
             4,
-            format!("self.{name} = {typ}Array.from_similar({name})\n"),
-        ));
+        );
     }
 
     code.push('\n');
 
-    code.push_str(&indent::indent_all_by(4, "# Optional components\n"));
+    code.push_text("# Optional components\n", 1, 4);
     for field in optional {
         let name = &field.name;
         let (typ, _) = quote_field_type_from_field(objects, field, true);
-        code.push_str(&indent::indent_all_by(
+        code.push_text(
+            format!("self.{name} = {typ}Array.from_similar({name})"),
+            1,
             4,
-            format!("self.{name} = {typ}Array.from_similar({name})\n"),
-        ));
+        );
     }
 
     code
diff --git a/crates/re_types_builder/src/codegen/rust.rs b/crates/re_types_builder/src/codegen/rust.rs
index 0a928185ae47..ae87dedf9398 100644
--- a/crates/re_types_builder/src/codegen/rust.rs
+++ b/crates/re_types_builder/src/codegen/rust.rs
@@ -8,20 +8,14 @@ use std::{
 };
 
 use crate::{
-    codegen::{
-        AUTOGEN_WARNING, RERUN_ATTR_COMPONENT_OPTIONAL, RERUN_ATTR_COMPONENT_RECOMMENDED,
-        RERUN_ATTR_COMPONENT_REQUIRED,
-    },
+    codegen::{StringExt as _, AUTOGEN_WARNING},
     ArrowRegistry, CodeGenerator, Docs, ElementType, Object, ObjectField, ObjectKind, Objects,
-    Type,
+    Type, RERUN_ATTR_COMPONENT_OPTIONAL, RERUN_ATTR_COMPONENT_RECOMMENDED,
+    RERUN_ATTR_COMPONENT_REQUIRED, RUST_ATTR_DERIVE, RUST_ATTR_REPR, RUST_ATTR_TUPLE_STRUCT,
 };
 
 // ---
 
-pub const ATTR_DERIVE: &str = "rust.attr.derive";
-pub const ATTR_REPR: &str = "rust.attr.repr";
-pub const ATTR_TUPLE_STRUCT: &str = "rust.attr.tuple_struct";
-
 pub struct RustCodeGenerator {
     crate_path: PathBuf,
 }
@@ -92,15 +86,7 @@ fn quote_objects(
         };
 
         let filepath = out_path.join(obj.filepath.file_name().unwrap());
-
-        match files.entry(filepath.clone()) {
-            std::collections::hash_map::Entry::Occupied(mut entry) => {
-                entry.get_mut().push(obj);
-            }
-            std::collections::hash_map::Entry::Vacant(entry) => {
-                entry.insert(vec![obj]);
-            }
-        };
+        files.entry(filepath.clone()).or_default().push(obj);
     }
 
     // (module_name, [object_name])
@@ -111,14 +97,9 @@ fn quote_objects(
         // NOTE: Isolating the file stem only works because we're handling datatypes, components
         // and archetypes separately (and even then it's a bit shady, eh).
         let names = objs.iter().map(|obj| obj.name.clone()).collect::<Vec<_>>();
-        match mods.entry(filepath.file_stem().unwrap().to_string_lossy().to_string()) {
-            std::collections::hash_map::Entry::Occupied(mut entry) => {
-                entry.get_mut().extend(names);
-            }
-            std::collections::hash_map::Entry::Vacant(entry) => {
-                entry.insert(names);
-            }
-        };
+        mods.entry(filepath.file_stem().unwrap().to_string_lossy().to_string())
+            .or_default()
+            .extend(names);
 
         filepaths.push(filepath.clone());
         let mut file = std::fs::File::create(&filepath)
@@ -126,11 +107,10 @@ fn quote_objects(
             .unwrap();
 
         let mut code = String::new();
-        code.push_str(&format!("// {AUTOGEN_WARNING}\n\n"));
+        code.push_text(format!("// {AUTOGEN_WARNING}"), 2, 0);
 
         for obj in objs {
-            code.push_str(&obj.code);
-            code.push('\n');
+            code.push_text(&obj.code, 1, 0);
         }
         file.write_all(code.as_bytes())
             .with_context(|| format!("{filepath:?}"))
@@ -143,17 +123,17 @@ fn quote_objects(
 
         let mut code = String::new();
 
-        code.push_str(&format!("// {AUTOGEN_WARNING}\n\n"));
+        code.push_text(format!("// {AUTOGEN_WARNING}"), 2, 0);
 
         for module in mods.keys() {
-            code.push_str(&format!("mod {module};\n"));
+            code.push_text(format!("mod {module};"), 1, 0);
 
             // Detect if someone manually created an extension file, and automatically
             // import it if so.
             let mut ext_path = out_path.join(format!("{module}_ext"));
             ext_path.set_extension("rs");
             if ext_path.exists() {
-                code.push_str(&format!("mod {module}_ext;\n"));
+                code.push_text(format!("mod {module}_ext;"), 1, 0);
             }
         }
 
@@ -161,7 +141,7 @@ fn quote_objects(
 
         for (module, names) in &mods {
             let names = names.join(", ");
-            code.push_str(&format!("pub use self::{module}::{{{names}}};\n"));
+            code.push_text(format!("pub use self::{module}::{{{names}}};"), 1, 0);
         }
 
         filepaths.push(path.clone());
@@ -200,23 +180,21 @@ impl QuotedObject {
 
         let mut code = String::new();
 
-        code.push_str(&quote_doc_from_docs(docs));
+        code.push_text(&quote_doc_from_docs(docs), 0, 0);
 
         if let Some(clause) = quote_derive_clause_from_obj(obj) {
-            code.push_str(&clause);
-            code.push('\n');
+            code.push_text(&clause, 1, 0);
         }
         if let Some(clause) = quote_repr_clause_from_obj(obj) {
-            code.push_str(&clause);
-            code.push('\n');
+            code.push_text(&clause, 1, 0);
         }
 
         let is_tuple_struct = is_tuple_struct_from_obj(obj);
 
         if is_tuple_struct {
-            code.push_str(&format!("pub struct {name}("));
+            code.push_text(&format!("pub struct {name}("), 0, 0);
         } else {
-            code.push_str(&format!("pub struct {name} {{\n"));
+            code.push_text(&format!("pub struct {name} {{"), 1, 0);
         }
 
         for field in fields {
@@ -233,7 +211,7 @@ impl QuotedObject {
                 deprecated: _,
             } = field;
 
-            code.push_str(&quote_doc_from_docs(docs));
+            code.push_text(&quote_doc_from_docs(docs), 0, 0);
 
             let (typ, _) = quote_field_type_from_field(field, false);
             let typ = if *required {
@@ -243,9 +221,9 @@ impl QuotedObject {
             };
 
             if is_tuple_struct {
-                code.push_str(&format!("pub {typ}"));
+                code.push_text(&format!("pub {typ}"), 0, 0);
             } else {
-                code.push_str(&format!("pub {name}: {typ},\n\n"));
+                code.push_text(&format!("pub {name}: {typ},"), 2, 0);
             }
         }
 
@@ -255,11 +233,10 @@ impl QuotedObject {
             code += "}\n\n";
         }
 
-        code.push_str(&quote_trait_impls_from_obj(arrow_registry, obj));
-        code.push('\n');
+        code.push_text(&quote_trait_impls_from_obj(arrow_registry, obj), 1, 0);
 
         if kind == &ObjectKind::Archetype {
-            code.push_str(&quote_builder_from_obj(obj));
+            code.push_text(&quote_builder_from_obj(obj), 0, 0);
         }
 
         let mut filepath = PathBuf::from(filepath);
@@ -289,18 +266,16 @@ impl QuotedObject {
 
         let mut code = String::new();
 
-        code.push_str(&quote_doc_from_docs(docs));
+        code.push_text(&quote_doc_from_docs(docs), 0, 0);
 
         if let Some(clause) = quote_derive_clause_from_obj(obj) {
-            code.push_str(&clause);
-            code.push('\n');
+            code.push_text(&clause, 1, 0);
         }
         if let Some(clause) = quote_repr_clause_from_obj(obj) {
-            code.push_str(&clause);
-            code.push('\n');
+            code.push_text(&clause, 1, 0);
         }
 
-        code.push_str(&format!("pub enum {name} {{\n"));
+        code.push_text(&format!("pub enum {name} {{"), 1, 0);
 
         for field in fields {
             let ObjectField {
@@ -315,17 +290,16 @@ impl QuotedObject {
                 deprecated: _,
             } = field;
 
-            code.push_str(&quote_doc_from_docs(docs));
+            code.push_text(&quote_doc_from_docs(docs), 0, 0);
 
             let (typ, _) = quote_field_type_from_field(field, false);
 
-            code.push_str(&format!("{name}({typ}),\n\n"));
+            code.push_text(&format!("{name}({typ}),"), 2, 0);
         }
 
         code += "}\n\n";
 
-        code.push_str(&quote_trait_impls_from_obj(arrow_registry, obj));
-        code.push('\n');
+        code.push_text(&quote_trait_impls_from_obj(arrow_registry, obj), 1, 0);
 
         let mut filepath = PathBuf::from(filepath);
         filepath.set_extension("rs");
@@ -353,6 +327,10 @@ fn quote_doc_from_docs(docs: &Docs) -> String {
 }
 
 /// Returns type name as string and whether it was force unwrapped.
+///
+/// Specifying `unwrap = true` will unwrap the final type before returning it, e.g. `Vec<String>`
+/// becomes just `String`.
+/// The returned boolean indicates whether there was anything to unwrap at all.
 fn quote_field_type_from_field(field: &ObjectField, unwrap: bool) -> (String, bool) {
     let mut unwrapped = false;
     let typ = &field.typ;
@@ -414,19 +392,19 @@ fn quote_type_from_element_type(typ: &ElementType) -> String {
 }
 
 fn quote_derive_clause_from_obj(obj: &Object) -> Option<String> {
-    obj.try_get_attr::<String>(ATTR_DERIVE)
+    obj.try_get_attr::<String>(RUST_ATTR_DERIVE)
         .map(|what| format!("#[derive({what})]"))
 }
 
 fn quote_repr_clause_from_obj(obj: &Object) -> Option<String> {
-    obj.try_get_attr::<String>(ATTR_REPR)
+    obj.try_get_attr::<String>(RUST_ATTR_REPR)
         .map(|what| format!("#[repr({what})]"))
 }
 
 fn is_tuple_struct_from_obj(obj: &Object) -> bool {
     obj.is_struct()
         && obj.fields.len() == 1
-        && obj.try_get_attr::<String>(ATTR_TUPLE_STRUCT).is_some()
+        && obj.try_get_attr::<String>(RUST_ATTR_TUPLE_STRUCT).is_some()
 }
 
 fn quote_trait_impls_from_obj(arrow_registry: &ArrowRegistry, obj: &Object) -> String {
@@ -571,7 +549,7 @@ fn quote_builder_from_obj(obj: &Object) -> String {
 
     let mut code = String::new();
 
-    code.push_str(&format!("impl {name} {{\n"));
+    code.push_text(&format!("impl {name} {{"), 1, 0);
     {
         // --- impl new() ---
 
@@ -591,7 +569,7 @@ fn quote_builder_from_obj(obj: &Object) -> String {
             })
             .collect::<Vec<_>>()
             .join(", ");
-        code.push_str(&format!("pub fn new({new_params}) -> Self {{\n"));
+        code.push_text(&format!("pub fn new({new_params}) -> Self {{"), 1, 0);
         {
             code += "Self {\n";
             {
@@ -599,16 +577,20 @@ fn quote_builder_from_obj(obj: &Object) -> String {
                     let (_, unwrapped) = quote_field_type_from_field(field, true);
                     if unwrapped {
                         // This was originally a vec/array!
-                        code.push_str(&format!(
-                            "{}: {}.into_iter().map(Into::into).collect(),\n",
-                            field.name, field.name
-                        ));
+                        code.push_text(
+                            &format!(
+                                "{}: {}.into_iter().map(Into::into).collect(),",
+                                field.name, field.name
+                            ),
+                            1,
+                            0,
+                        );
                     } else {
-                        code.push_str(&format!("{}: {}.into(),\n", field.name, field.name));
+                        code.push_text(&format!("{}: {}.into(),", field.name, field.name), 1, 0);
                     }
                 }
                 for field in &optional {
-                    code.push_str(&format!("{}: None,\n", field.name));
+                    code.push_text(&format!("{}: None,", field.name), 1, 0);
                 }
             }
             code += "}\n";
@@ -623,21 +605,27 @@ fn quote_builder_from_obj(obj: &Object) -> String {
 
             if unwrapped {
                 // This was originally a vec/array!
-                code.push_str(&format!(
-                    "pub fn with_{name}(mut self, {name}: impl IntoIterator<Item = impl Into<{typ}>>) -> Self {{\n",
-                ));
+                code.push_text(&format!(
+                    "pub fn with_{name}(mut self, {name}: impl IntoIterator<Item = impl Into<{typ}>>) -> Self {{",
+                ), 1, 0);
                 {
-                    code.push_str(&format!(
-                        "self.{name} = Some({name}.into_iter().map(Into::into).collect());\n"
-                    ));
+                    code.push_text(
+                        &format!(
+                            "self.{name} = Some({name}.into_iter().map(Into::into).collect());"
+                        ),
+                        1,
+                        0,
+                    );
                     code += "self\n";
                 }
             } else {
-                code.push_str(&format!(
-                    "pub fn with_{name}(mut self, {name}: impl Into<{typ}>) -> Self {{\n",
-                ));
+                code.push_text(
+                    &format!("pub fn with_{name}(mut self, {name}: impl Into<{typ}>) -> Self {{",),
+                    1,
+                    0,
+                );
                 {
-                    code.push_str(&format!("self.{name} = Some({name}.into());\n"));
+                    code.push_text(&format!("self.{name} = Some({name}.into());"), 1, 0);
                     code += "self\n";
                 }
             }
diff --git a/crates/re_types_builder/src/lib.rs b/crates/re_types_builder/src/lib.rs
index 436126e7b885..71669189d7f6 100644
--- a/crates/re_types_builder/src/lib.rs
+++ b/crates/re_types_builder/src/lib.rs
@@ -99,12 +99,31 @@ pub use self::objects::{
     Attributes, Docs, ElementType, Object, ObjectField, ObjectKind, Objects, Type,
 };
 
+// --- Attributes ---
+
+pub const ARROW_ATTR_TRANSPARENT: &str = "arrow.attr.transparent";
+pub const ARROW_ATTR_SPARSE_UNION: &str = "arrow.attr.sparse_union";
+
+pub const RERUN_ATTR_COMPONENT_REQUIRED: &str = "rerun.attr.component_required";
+pub const RERUN_ATTR_COMPONENT_RECOMMENDED: &str = "rerun.attr.component_recommended";
+pub const RERUN_ATTR_COMPONENT_OPTIONAL: &str = "rerun.attr.component_optional";
+
+pub const PYTHON_ATTR_TRANSPARENT: &str = "python.attr.transparent";
+pub const PYTHON_ATTR_ALIASES: &str = "python.attr.aliases";
+pub const PYTHON_ATTR_ARRAY_ALIASES: &str = "python.attr.array_aliases";
+
+pub const RUST_ATTR_DERIVE: &str = "rust.attr.derive";
+pub const RUST_ATTR_REPR: &str = "rust.attr.repr";
+pub const RUST_ATTR_TUPLE_STRUCT: &str = "rust.attr.tuple_struct";
+
 // --- Entrypoints ---
 
 use std::path::{Path, PathBuf};
 
 /// Compiles binary reflection dumps from flatbuffers definitions.
 ///
+/// Requires `flatc` available in $PATH.
+///
 /// Panics on error.
 ///
 /// - `include_dir_path`: path to the root directory of the fbs definition tree.
@@ -141,27 +160,14 @@ pub fn compile_binary_schemas(
     .unwrap();
 }
 
-/// Generates Rust code from a set of flatbuffers definitions.
-///
-/// Panics on error.
-///
-/// - `include_dir_path`: path to the root directory of the fbs definition tree.
-/// - `output_crate_path`: path to the root of the output crate.
-/// - `entrypoint_path`: path to the root file of the fbs definition tree.
-///
-/// E.g.:
-/// ```no_run
-/// re_types_builder::generate_rust_code(
-///     "./definitions",
-///     ".",
-///     "./definitions/rerun/archetypes.fbs",
-/// );
-/// ```
-pub fn generate_rust_code(
+/// Handles the first 3 language-agnostic passes of the codegen pipeline:
+/// 1. Generate binary reflection dumps for our definitions.
+/// 2. Run the semantic pass
+/// 3. Compute the Arrow registry
+fn generate_lang_agnostic(
     include_dir_path: impl AsRef<Path>,
-    output_crate_path: impl AsRef<Path>,
     entrypoint_path: impl AsRef<Path>,
-) {
+) -> (Objects, ArrowRegistry) {
     use xshell::Shell;
 
     let sh = Shell::new().unwrap();
@@ -189,6 +195,33 @@ pub fn generate_rust_code(
         arrow_registry.register(obj);
     }
 
+    (objects, arrow_registry)
+}
+
+/// Generates Rust code from a set of flatbuffers definitions.
+///
+/// Panics on error.
+///
+/// - `include_dir_path`: path to the root directory of the fbs definition tree.
+/// - `output_crate_path`: path to the root of the output crate.
+/// - `entrypoint_path`: path to the root file of the fbs definition tree.
+///
+/// E.g.:
+/// ```no_run
+/// re_types_builder::generate_rust_code(
+///     "./definitions",
+///     ".",
+///     "./definitions/rerun/archetypes.fbs",
+/// );
+/// ```
+pub fn generate_rust_code(
+    include_dir_path: impl AsRef<Path>,
+    output_crate_path: impl AsRef<Path>,
+    entrypoint_path: impl AsRef<Path>,
+) {
+    // passes 1 through 3: bfbs, semantic, arrow registry
+    let (objects, arrow_registry) = generate_lang_agnostic(include_dir_path, entrypoint_path);
+
     // generate rust code
     let mut gen = RustCodeGenerator::new(output_crate_path.as_ref());
     let _filepaths = gen.quote(&objects, &arrow_registry);
@@ -215,32 +248,8 @@ pub fn generate_python_code(
     output_pkg_path: impl AsRef<Path>,
     entrypoint_path: impl AsRef<Path>,
 ) {
-    use xshell::Shell;
-
-    let sh = Shell::new().unwrap();
-    let tmp = sh.create_temp_dir().unwrap();
-
-    let entrypoint_path = entrypoint_path.as_ref();
-    let entrypoint_filename = entrypoint_path.file_name().unwrap();
-
-    // generate bfbs definitions
-    compile_binary_schemas(include_dir_path, tmp.path(), entrypoint_path);
-
-    let mut binary_entrypoint_path = PathBuf::from(entrypoint_filename);
-    binary_entrypoint_path.set_extension("bfbs");
-
-    // semantic pass: high level objects from low-level reflection data
-    let objects = Objects::from_buf(
-        sh.read_binary_file(tmp.path().join(binary_entrypoint_path))
-            .unwrap()
-            .as_slice(),
-    );
-
-    // create and fill out arrow registry
-    let mut arrow_registry = ArrowRegistry::default();
-    for obj in objects.ordered_objects(None) {
-        arrow_registry.register(obj);
-    }
+    // passes 1 through 3: bfbs, semantic, arrow registry
+    let (objects, arrow_registry) = generate_lang_agnostic(include_dir_path, entrypoint_path);
 
     // generate python code
     let mut gen = PythonCodeGenerator::new(output_pkg_path.as_ref());
diff --git a/crates/re_types_builder/src/objects.rs b/crates/re_types_builder/src/objects.rs
index 343e40583ed1..677779a7c7b3 100644
--- a/crates/re_types_builder/src/objects.rs
+++ b/crates/re_types_builder/src/objects.rs
@@ -443,7 +443,7 @@ pub struct ObjectField {
 
     /// Whether the field is required.
     ///
-    /// Always true for `struct` types.
+    /// Always true for IDL definitions using flatbuffers' `struct` type (as opposed to `table`).
     pub required: bool,
 
     /// Whether the field is deprecated.
@@ -642,8 +642,6 @@ impl Type {
                 let union = &enums[field_type.index() as usize];
                 Self::Object(union.name().to_owned())
             }
-            // NOTE: flatbuffers doesn't support directly nesting multiple layers of arrays, they
-            // always have to be wrapped into intermediate layers of structs or tables.
             FbsBaseType::Array => Self::Array {
                 elem_type: ElementType::from_raw_base_type(
                     enums,
@@ -718,8 +716,6 @@ impl ElementType {
                 flatten_scalar_wrappers(obj)
             }
             FbsBaseType::Union => unimplemented!("{inner_type:#?}"), // NOLINT
-            // NOTE: flatbuffers doesn't support directly nesting multiple layers of arrays, they
-            // always have to be wrapped into intermediate layers of structs or tables.
             FbsBaseType::None
             | FbsBaseType::UType
             | FbsBaseType::Array

From dabd85bf9b6e258b1e70be443fd310d1313719ae Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Sun, 11 Jun 2023 21:56:46 +0200
Subject: [PATCH 14/18] introduce re_types

---
 Cargo.lock                                    |  16 +++
 Cargo.toml                                    |   1 +
 crates/re_types/Cargo.toml                    |  61 ++++++++++
 crates/re_types/README.md                     |  12 ++
 crates/re_types/build.rs                      | 104 ++++++++++++++++++
 .../re_types/definitions/arrow/attributes.fbs |  12 ++
 .../re_types/definitions/fbs/attributes.fbs   |  16 +++
 crates/re_types/definitions/fbs/scalars.fbs   |  10 ++
 .../definitions/python/attributes.fbs         |  16 +++
 .../re_types/definitions/rerun/archetypes.fbs |   1 +
 .../re_types/definitions/rust/attributes.fbs  |  15 +++
 crates/re_types/source_hash.txt               |   4 +
 crates/re_types/src/archetypes/mod.rs         |   1 +
 crates/re_types/src/components/mod.rs         |   1 +
 crates/re_types/src/datatypes/mod.rs          |   1 +
 crates/re_types/src/lib.rs                    | 104 ++++++++++++++++++
 16 files changed, 375 insertions(+)
 create mode 100644 crates/re_types/Cargo.toml
 create mode 100644 crates/re_types/README.md
 create mode 100644 crates/re_types/build.rs
 create mode 100644 crates/re_types/definitions/arrow/attributes.fbs
 create mode 100644 crates/re_types/definitions/fbs/attributes.fbs
 create mode 100644 crates/re_types/definitions/fbs/scalars.fbs
 create mode 100644 crates/re_types/definitions/python/attributes.fbs
 create mode 100644 crates/re_types/definitions/rerun/archetypes.fbs
 create mode 100644 crates/re_types/definitions/rust/attributes.fbs
 create mode 100644 crates/re_types/source_hash.txt
 create mode 100644 crates/re_types/src/archetypes/mod.rs
 create mode 100644 crates/re_types/src/components/mod.rs
 create mode 100644 crates/re_types/src/datatypes/mod.rs
 create mode 100644 crates/re_types/src/lib.rs

diff --git a/Cargo.lock b/Cargo.lock
index b5c6926c1ca1..306ba7d675c4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4497,6 +4497,22 @@ dependencies = [
  "web-time",
 ]
 
+[[package]]
+name = "re_types"
+version = "0.7.0-alpha.0"
+dependencies = [
+ "arrow2",
+ "bytemuck",
+ "document-features",
+ "ecolor",
+ "glam",
+ "itertools",
+ "macaw",
+ "re_build_tools",
+ "re_types_builder",
+ "xshell",
+]
+
 [[package]]
 name = "re_types_builder"
 version = "0.7.0-alpha.0"
diff --git a/Cargo.toml b/Cargo.toml
index 13b1df640125..f0a47151f6b6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -56,6 +56,7 @@ re_tensor_ops = { path = "crates/re_tensor_ops", version = "0.7.0-alpha.0", defa
 re_time_panel = { path = "crates/re_time_panel", version = "=0.7.0-alpha.0", default-features = false }
 re_tracing = { path = "crates/re_tracing", version = "0.7.0-alpha.0", default-features = false }
 re_tuid = { path = "crates/re_tuid", version = "0.7.0-alpha.0", default-features = false }
+re_types = { path = "crates/re_types", version = "=0.7.0-alpha.0", default-features = false }
 re_types_builder = { path = "crates/re_types_builder", version = "=0.7.0-alpha.0", default-features = false }
 re_ui = { path = "crates/re_ui", version = "0.7.0-alpha.0", default-features = false }
 re_viewer = { path = "crates/re_viewer", version = "0.7.0-alpha.0", default-features = false }
diff --git a/crates/re_types/Cargo.toml b/crates/re_types/Cargo.toml
new file mode 100644
index 000000000000..e3b1b9dc1b2a
--- /dev/null
+++ b/crates/re_types/Cargo.toml
@@ -0,0 +1,61 @@
+[package]
+name = "re_types"
+authors.workspace = true
+description = "The standard Rerun data types, component types, and archetypes."
+edition.workspace = true
+homepage.workspace = true
+include.workspace = true
+license.workspace = true
+publish = true
+readme = "README.md"
+repository.workspace = true
+rust-version.workspace = true
+version.workspace = true
+
+
+[package.metadata.docs.rs]
+all-features = true
+
+
+[features]
+default = []
+
+## Enable color conversions.
+ecolor = ["dep:ecolor"]
+
+## Add support for some math operations using [`glam`](https://crates.io/crates/glam/).
+glam = ["dep:glam", "dep:macaw"]
+
+
+[dependencies]
+
+# External
+arrow2 = { workspace = true, features = [
+  "io_ipc",
+  "io_print",
+  "compute_concatenate",
+] }
+bytemuck = { version = "1.11", features = ["derive", "extern_crate_alloc"] }
+document-features = "0.2"
+
+# External (optional)
+ecolor = { workspace = true, optional = true }
+glam = { workspace = true, optional = true }
+macaw = { workspace = true, optional = true }
+
+
+[dev-dependencies]
+
+# External
+glam.workspace = true
+itertools.workspace = true
+
+
+[build-dependencies]
+
+# Rerun
+re_build_tools.workspace = true
+re_types_builder.workspace = true
+
+# External
+xshell = "0.2"
diff --git a/crates/re_types/README.md b/crates/re_types/README.md
new file mode 100644
index 000000000000..62c1ebddf06a
--- /dev/null
+++ b/crates/re_types/README.md
@@ -0,0 +1,12 @@
+# re_types
+
+Part of the [`rerun`](https://github.com/rerun-io/rerun) family of crates.
+
+[![Latest version](https://img.shields.io/crates/v/re_types.svg)](https://crates.io/crates/re_types)
+[![Documentation](https://docs.rs/re_types/badge.svg)](https://docs.rs/re_types)
+![MIT](https://img.shields.io/badge/license-MIT-blue.svg)
+![Apache](https://img.shields.io/badge/license-Apache-blue.svg)
+
+The standard Rerun data types, component types, and archetypes.
+
+This crate includes both the language-agnostic definitions (flatbuffers IDL) as well as the generated code.
diff --git a/crates/re_types/build.rs b/crates/re_types/build.rs
new file mode 100644
index 000000000000..34b976a07ea2
--- /dev/null
+++ b/crates/re_types/build.rs
@@ -0,0 +1,104 @@
+//! Generates Rust & Python code from flatbuffers definitions.
+
+use xshell::{cmd, Shell};
+
+use re_build_tools::{
+    compute_crate_hash, compute_dir_hash, compute_strings_hash, is_tracked_env_var_set, iter_dir,
+    read_versioning_hash, rerun_if_changed, rerun_if_changed_or_doesnt_exist,
+    write_versioning_hash,
+};
+
+// NOTE: Don't need to add extra context to xshell invocations, it does so on its own.
+
+// ---
+
+const SOURCE_HASH_PATH: &str = "./source_hash.txt";
+const DEFINITIONS_DIR_PATH: &str = "./definitions";
+const RUST_OUTPUT_DIR_PATH: &str = ".";
+const PYTHON_OUTPUT_DIR_PATH: &str = "../../rerun_py/rerun2";
+
+fn main() {
+    if std::env::var("CI").is_ok() {
+        // Don't run on CI!
+        //
+        // The code we're generating here is actual source code that gets committed into the
+        // repository.
+        return;
+    }
+
+    if !is_tracked_env_var_set("IS_IN_RERUN_WORKSPACE") {
+        // Only run if we are in the rerun workspace, not on users machines.
+        return;
+    }
+    if is_tracked_env_var_set("RERUN_IS_PUBLISHING") {
+        // We don't need to rebuild - we should have done so beforehand!
+        // See `RELEASES.md`
+        return;
+    }
+
+    rerun_if_changed_or_doesnt_exist(SOURCE_HASH_PATH);
+    for path in iter_dir(DEFINITIONS_DIR_PATH, Some(&[".fbs"])) {
+        rerun_if_changed(&path);
+    }
+
+    // NOTE: We need to hash both the flatbuffers definitions as well as the source code of the
+    // code generator itself!
+    let re_types_builder_hash = compute_crate_hash("re_types_builder");
+    let cur_hash = read_versioning_hash(SOURCE_HASH_PATH);
+    let new_hash = compute_dir_hash(DEFINITIONS_DIR_PATH, Some(&[".fbs"]));
+    let new_hash_final = compute_strings_hash(&[&re_types_builder_hash, &new_hash]);
+
+    // Leave these be please, very useful when debugging.
+    eprintln!("re_types_builder_hash: {re_types_builder_hash:?}");
+    eprintln!("cur_hash: {cur_hash:?}");
+    eprintln!("new_hash: {new_hash:?}");
+    eprintln!("new_hash_final: {new_hash_final:?}");
+
+    if let Some(cur_hash) = cur_hash {
+        if cur_hash == new_hash_final {
+            // Neither the source of the code generator nor the IDL definitions have changed, no need
+            // to do anything at this point.
+            return;
+        }
+    }
+
+    let sh = Shell::new().unwrap();
+
+    re_types_builder::generate_rust_code(
+        DEFINITIONS_DIR_PATH,
+        RUST_OUTPUT_DIR_PATH,
+        "./definitions/rerun/archetypes.fbs",
+    );
+
+    // NOTE: We're purposefully ignoring the error here.
+    //
+    // In the very unlikely chance that the user doesn't have `cargo` in their $PATH, there's
+    // still no good reason to fail the build.
+    //
+    // The CI will catch the unformatted files at PR time and complain appropriately anyhow.
+    cmd!(sh, "cargo fmt").run().ok();
+
+    re_types_builder::generate_python_code(
+        DEFINITIONS_DIR_PATH,
+        PYTHON_OUTPUT_DIR_PATH,
+        "./definitions/rerun/archetypes.fbs",
+    );
+
+    // NOTE: We're purposefully ignoring the error here.
+    //
+    // If the user doesn't have `black` in their $PATH, there's still no good reason to fail
+    // the build.
+    //
+    // The CI will catch the unformatted files at PR time and complain appropriately anyhow.
+    cmd!(sh, "black {PYTHON_OUTPUT_DIR_PATH}").run().ok();
+
+    // NOTE: We're purposefully ignoring the error here.
+    //
+    // If the user doesn't have `ruff` in their $PATH, there's still no good reason to fail
+    // the build.
+    //
+    // The CI will catch the unformatted files at PR time and complain appropriately anyhow.
+    cmd!(sh, "ruff --fix {PYTHON_OUTPUT_DIR_PATH}").run().ok();
+
+    write_versioning_hash(SOURCE_HASH_PATH, new_hash_final);
+}
diff --git a/crates/re_types/definitions/arrow/attributes.fbs b/crates/re_types/definitions/arrow/attributes.fbs
new file mode 100644
index 000000000000..54374cc07643
--- /dev/null
+++ b/crates/re_types/definitions/arrow/attributes.fbs
@@ -0,0 +1,12 @@
+namespace arrow;
+
+/// Marks a union as sparse from Arrow's standpoint, affecting its Arrow datatype.
+///
+/// Only applies to unions.
+attribute "arrow.attr.sparse_union";
+
+/// Marks a single-field object as transparent from Arrow's standpoint, affecting its Arrow
+/// datatype.
+///
+/// This is generally most useful for getting rid of extraneous `struct` layers.
+attribute "arrow.attr.transparent";
diff --git a/crates/re_types/definitions/fbs/attributes.fbs b/crates/re_types/definitions/fbs/attributes.fbs
new file mode 100644
index 000000000000..9487163b54fb
--- /dev/null
+++ b/crates/re_types/definitions/fbs/attributes.fbs
@@ -0,0 +1,16 @@
+namespace fbs.attributes;
+
+/// Mandatory attribute that applies to all kinds of objects: structs, enums, unions and even the
+/// fields within.
+///
+/// This defines a stable order between objects of the same kind, e.g. the order in which fields of a
+/// struct should be laid out when generating code.
+/// This is always required since flatbuffers works entirely with unordered maps internally, which
+/// would results in flaky code generation.
+///
+/// In unions, this effectively defines the arrow type of each variant, since that depends on the
+/// fields's order!
+///
+/// NOTE: We do not use flatbuffers' builtin `id` attribute as it only works on `table`s, whereas we
+/// need a stable order for all kinds of things.
+attribute "order";
diff --git a/crates/re_types/definitions/fbs/scalars.fbs b/crates/re_types/definitions/fbs/scalars.fbs
new file mode 100644
index 000000000000..bb6fcd75063b
--- /dev/null
+++ b/crates/re_types/definitions/fbs/scalars.fbs
@@ -0,0 +1,10 @@
+/// Unions cannot directly refer to scalar types, they need to be wrapped in a struct or table
+/// first.
+/// This package provides pre-wrapped scalars that will be automatically flattened down to their
+/// inner type by our parsers.
+namespace fbs.scalars;
+
+/// Flattens down to a 32-bit float.
+struct Float32 {
+  v: float;
+}
diff --git a/crates/re_types/definitions/python/attributes.fbs b/crates/re_types/definitions/python/attributes.fbs
new file mode 100644
index 000000000000..99b357f72abf
--- /dev/null
+++ b/crates/re_types/definitions/python/attributes.fbs
@@ -0,0 +1,16 @@
+namespace python.attributes;
+
+/// Marks a field as transparent, meaning its type will be replaced by the underlying type.
+///
+/// Only applies to field whose types have a single-field.
+attribute "python.attr.transparent";
+
+/// Defines the type aliases for a component, e.g. the types that make up `ComponentLike`.
+///
+/// Only applies to structs/unions that are components.
+attribute "python.attr.aliases";
+
+/// Defines the array type aliases for a component, e.g. the types that make up `ComponentArrayLike`.
+///
+/// Only applies to structs/unions that are components.
+attribute "python.attr.array_aliases";
diff --git a/crates/re_types/definitions/rerun/archetypes.fbs b/crates/re_types/definitions/rerun/archetypes.fbs
new file mode 100644
index 000000000000..e8f07787a567
--- /dev/null
+++ b/crates/re_types/definitions/rerun/archetypes.fbs
@@ -0,0 +1 @@
+namespace rerun.archetypes;
diff --git a/crates/re_types/definitions/rust/attributes.fbs b/crates/re_types/definitions/rust/attributes.fbs
new file mode 100644
index 000000000000..58a8fac6b070
--- /dev/null
+++ b/crates/re_types/definitions/rust/attributes.fbs
@@ -0,0 +1,15 @@
+namespace rust.attributes;
+
+/// Apply to a struct or table object to generate a tuple struct.
+///
+/// The type definition of the target object must have exactly a single field.
+attribute "rust.attr.tuple_struct";
+
+/// Apply to any object to generate a #derive clause.
+///
+/// The value of the attribute will be trimmed out but otherwise left as-is.
+/// E.g. "rust.attr.derive": "Debug, Clone, Copy"`.
+attribute "rust.attr.derive";
+
+/// Apply to any object to generate a #repr clause with the specified value.
+attribute "rust.attr.repr";
diff --git a/crates/re_types/source_hash.txt b/crates/re_types/source_hash.txt
new file mode 100644
index 000000000000..6be879f6278b
--- /dev/null
+++ b/crates/re_types/source_hash.txt
@@ -0,0 +1,4 @@
+# This is a sha256 hash for all direct and indirect dependencies of this crate's build script.
+# It can be safely removed at anytime to force the build script to run again.
+# Check out build.rs to see how it's computed.
+e4b94e84d8869a38e732e777b6ab8e7d4ae7780e04cc3c89512e444cdda5ee50
\ No newline at end of file
diff --git a/crates/re_types/src/archetypes/mod.rs b/crates/re_types/src/archetypes/mod.rs
new file mode 100644
index 000000000000..cf43c16c6a0e
--- /dev/null
+++ b/crates/re_types/src/archetypes/mod.rs
@@ -0,0 +1 @@
+// NOTE: This file was autogenerated by re_types_builder; DO NOT EDIT.
diff --git a/crates/re_types/src/components/mod.rs b/crates/re_types/src/components/mod.rs
new file mode 100644
index 000000000000..cf43c16c6a0e
--- /dev/null
+++ b/crates/re_types/src/components/mod.rs
@@ -0,0 +1 @@
+// NOTE: This file was autogenerated by re_types_builder; DO NOT EDIT.
diff --git a/crates/re_types/src/datatypes/mod.rs b/crates/re_types/src/datatypes/mod.rs
new file mode 100644
index 000000000000..cf43c16c6a0e
--- /dev/null
+++ b/crates/re_types/src/datatypes/mod.rs
@@ -0,0 +1 @@
+// NOTE: This file was autogenerated by re_types_builder; DO NOT EDIT.
diff --git a/crates/re_types/src/lib.rs b/crates/re_types/src/lib.rs
new file mode 100644
index 000000000000..e6ddbfc3f92f
--- /dev/null
+++ b/crates/re_types/src/lib.rs
@@ -0,0 +1,104 @@
+//! The standard Rerun data types, component types, and archetypes.
+//!
+//! This crate contains both the IDL definitions for Rerun types (flatbuffers) as well as the code
+//! generated from those using `re_types_builder`.
+//!
+//!
+//! ### Organization
+//!
+//! - `definitions/` contains IDL definitions for all Rerun types (data, components, archetypes).
+//! - `src/` contains the code generated for Rust.
+//! - `rerun_py/rerun2/` (at the root of this workspace) contains the code generated for Python.
+//!
+//! While most of the code in this crate is auto-generated, some manual extensions are littered
+//! throughout: look for files ending in `_ext.rs` or `_ext.py` (also see the "Extensions" section
+//! of this document).
+//!
+//!
+//! ### Build cache
+//!
+//! Updating either the source code of the code generator itself (`re_types_builder`) or any of the
+//! .fbs files should re-trigger the code generation process the next time `re_types` is built.
+//! Manual extension files will be left untouched.
+//!
+//! Caching is controlled by a versioning hash that is stored in `store_hash.txt`.
+//! If you suspect something is wrong with the caching mechanism and that your changes aren't taken
+//! into account when they should, try and remove `source_hash.txt`.
+//! If that fixes the issue, you've found a bug.
+//!
+//!
+//! ### How-to: add a new datatype/component/archetype
+//!
+//! Create the appropriate .fbs file in the appropriate place, and make sure it gets included in
+//! some way (most likely indirectly) by `archetypes.fbs`, which is the main entrypoint for
+//! codegen.
+//! Generally, the easiest thing to do is to add your new type to one of the centralized manifests,
+//! e.g. for a new component, include it into `components.fbs`.
+//!
+//! Your file should get picked up automatically by the code generator.
+//! Once the code for your new component has been generated, implement whatever extensions you need
+//! and make sure to tests any custom constructors you add.
+//!
+//!
+//! ### How-to: remove an existing datatype/component/archetype
+//!
+//! Simply get rid of the type in question and rebuild `re_types` to trigger codegen.
+//!
+//! Beware though: if you remove a whole definition file re-running codegen will not remove the
+//! associated generated files, you'll have to do that yourself.
+//!
+//!
+//! ### Extensions
+//!
+//!
+//! #### Rust
+//!
+//! Generated Rust code can be manually extended by adding sibling files with the `_ext.rs`
+//! prefix. E.g. to extend `vec2d.rs`, create a `vec2d_ext.rs`.
+//!
+//! Trigger the codegen (e.g. by removing `source_hash.txt`) to generate the right `mod` clauses
+//! automatically.
+//!
+//! The simplest way to get started is to look at any of the existing examples.
+//!
+//!
+//! #### Python
+//!
+//! Generated Python code can be manually extended by adding a sibling file with the `_ext.py`
+//! prefix. E.g. to extend `vec2d.py`, create a `vec2d_ext.py`.
+//!
+//! This sibling file needs to implement an extension class that is mixed in with the
+//! auto-generated class.
+//! The simplest way to get started is to look at any of the existing examples.
+
+use std::borrow::Cow;
+
+/// A [`Datatype`] describes plain old data.
+pub trait Datatype {
+    fn name() -> Cow<'static, str>;
+
+    fn to_arrow_datatype() -> arrow2::datatypes::DataType;
+}
+
+pub trait Component {
+    fn name() -> Cow<'static, str>;
+
+    fn to_arrow_datatype() -> arrow2::datatypes::DataType;
+}
+
+pub trait Archetype {
+    fn name() -> Cow<'static, str>;
+
+    fn required_components() -> Vec<Cow<'static, str>>;
+    fn recommended_components() -> Vec<Cow<'static, str>>;
+    fn optional_components() -> Vec<Cow<'static, str>>;
+
+    fn to_arrow_datatypes() -> Vec<arrow2::datatypes::DataType>;
+}
+
+/// Number of decimals shown for all vector display methods.
+pub const DISPLAY_PRECISION: usize = 3;
+
+pub mod archetypes;
+pub mod components;
+pub mod datatypes;

From b5fd082ef90703203bd9afe4af91c563aaf83c89 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Sun, 11 Jun 2023 22:35:07 +0200
Subject: [PATCH 15/18] self-review

---
 crates/re_types/build.rs                      | 24 ++++++++++++-------
 .../re_types/definitions/arrow/attributes.fbs |  9 ++++---
 .../re_types/definitions/fbs/attributes.fbs   |  4 ++--
 .../definitions/python/attributes.fbs         |  2 +-
 crates/re_types/source_hash.txt               |  2 +-
 5 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/crates/re_types/build.rs b/crates/re_types/build.rs
index 34b976a07ea2..687d7507d590 100644
--- a/crates/re_types/build.rs
+++ b/crates/re_types/build.rs
@@ -43,19 +43,19 @@ fn main() {
 
     // NOTE: We need to hash both the flatbuffers definitions as well as the source code of the
     // code generator itself!
-    let re_types_builder_hash = compute_crate_hash("re_types_builder");
     let cur_hash = read_versioning_hash(SOURCE_HASH_PATH);
-    let new_hash = compute_dir_hash(DEFINITIONS_DIR_PATH, Some(&[".fbs"]));
-    let new_hash_final = compute_strings_hash(&[&re_types_builder_hash, &new_hash]);
+    let re_types_builder_hash = compute_crate_hash("re_types_builder");
+    let definitions_hash = compute_dir_hash(DEFINITIONS_DIR_PATH, Some(&[".fbs"]));
+    let new_hash = compute_strings_hash(&[&re_types_builder_hash, &definitions_hash]);
 
     // Leave these be please, very useful when debugging.
     eprintln!("re_types_builder_hash: {re_types_builder_hash:?}");
     eprintln!("cur_hash: {cur_hash:?}");
+    eprintln!("definitions_hash: {definitions_hash:?}");
     eprintln!("new_hash: {new_hash:?}");
-    eprintln!("new_hash_final: {new_hash_final:?}");
 
     if let Some(cur_hash) = cur_hash {
-        if cur_hash == new_hash_final {
+        if cur_hash == new_hash {
             // Neither the source of the code generator nor the IDL definitions have changed, no need
             // to do anything at this point.
             return;
@@ -72,10 +72,10 @@ fn main() {
 
     // NOTE: We're purposefully ignoring the error here.
     //
-    // In the very unlikely chance that the user doesn't have `cargo` in their $PATH, there's
-    // still no good reason to fail the build.
+    // In the very unlikely chance that the user doesn't have the `fmt` component installed,
+    // there's still no good reason to fail the build.
     //
-    // The CI will catch the unformatted files at PR time and complain appropriately anyhow.
+    // The CI will catch the unformatted file at PR time and complain appropriately anyhow.
     cmd!(sh, "cargo fmt").run().ok();
 
     re_types_builder::generate_python_code(
@@ -84,6 +84,12 @@ fn main() {
         "./definitions/rerun/archetypes.fbs",
     );
 
+    // NOTE: This requires both `black` and `ruff` to be in $PATH, but only for contributors,
+    // not end users.
+    // Even for contributors, `black` and `ruff` won't be needed unless they edit some of the
+    // .fbs files... and even then, this won't crash if they are missing, it will just fail to pass
+    // the CI!
+
     // NOTE: We're purposefully ignoring the error here.
     //
     // If the user doesn't have `black` in their $PATH, there's still no good reason to fail
@@ -100,5 +106,5 @@ fn main() {
     // The CI will catch the unformatted files at PR time and complain appropriately anyhow.
     cmd!(sh, "ruff --fix {PYTHON_OUTPUT_DIR_PATH}").run().ok();
 
-    write_versioning_hash(SOURCE_HASH_PATH, new_hash_final);
+    write_versioning_hash(SOURCE_HASH_PATH, new_hash);
 }
diff --git a/crates/re_types/definitions/arrow/attributes.fbs b/crates/re_types/definitions/arrow/attributes.fbs
index 54374cc07643..33c81c7dfb59 100644
--- a/crates/re_types/definitions/arrow/attributes.fbs
+++ b/crates/re_types/definitions/arrow/attributes.fbs
@@ -1,12 +1,15 @@
 namespace arrow;
 
-/// Marks a union as sparse from Arrow's standpoint, affecting its Arrow datatype.
+/// Marks a union as sparse, affecting its Arrow datatype.
+///
+/// This does _not_ affect the object generated in Python or Rust, this is a pure Arrow concern!
 ///
 /// Only applies to unions.
 attribute "arrow.attr.sparse_union";
 
-/// Marks a single-field object as transparent from Arrow's standpoint, affecting its Arrow
-/// datatype.
+/// Marks a single-field object as transparent, affecting its Arrow datatype.
+///
+/// This does _not_ affect the object generated in Python or Rust, this is a pure Arrow concern!
 ///
 /// This is generally most useful for getting rid of extraneous `struct` layers.
 attribute "arrow.attr.transparent";
diff --git a/crates/re_types/definitions/fbs/attributes.fbs b/crates/re_types/definitions/fbs/attributes.fbs
index 9487163b54fb..cdf311181ef6 100644
--- a/crates/re_types/definitions/fbs/attributes.fbs
+++ b/crates/re_types/definitions/fbs/attributes.fbs
@@ -8,8 +8,8 @@ namespace fbs.attributes;
 /// This is always required since flatbuffers works entirely with unordered maps internally, which
 /// would results in flaky code generation.
 ///
-/// In unions, this effectively defines the arrow type of each variant, since that depends on the
-/// fields's order!
+/// In unions, this effectively defines the arrow tag of each variant, since the tag depends on the
+/// fields's order in the datatype!
 ///
 /// NOTE: We do not use flatbuffers' builtin `id` attribute as it only works on `table`s, whereas we
 /// need a stable order for all kinds of things.
diff --git a/crates/re_types/definitions/python/attributes.fbs b/crates/re_types/definitions/python/attributes.fbs
index 99b357f72abf..4160bdc0c429 100644
--- a/crates/re_types/definitions/python/attributes.fbs
+++ b/crates/re_types/definitions/python/attributes.fbs
@@ -2,7 +2,7 @@ namespace python.attributes;
 
 /// Marks a field as transparent, meaning its type will be replaced by the underlying type.
 ///
-/// Only applies to field whose types have a single-field.
+/// Only applies to fields whose type is an object with a single-field.
 attribute "python.attr.transparent";
 
 /// Defines the type aliases for a component, e.g. the types that make up `ComponentLike`.
diff --git a/crates/re_types/source_hash.txt b/crates/re_types/source_hash.txt
index 6be879f6278b..45db6bc3ce6b 100644
--- a/crates/re_types/source_hash.txt
+++ b/crates/re_types/source_hash.txt
@@ -1,4 +1,4 @@
 # This is a sha256 hash for all direct and indirect dependencies of this crate's build script.
 # It can be safely removed at anytime to force the build script to run again.
 # Check out build.rs to see how it's computed.
-e4b94e84d8869a38e732e777b6ab8e7d4ae7780e04cc3c89512e444cdda5ee50
\ No newline at end of file
+5a4275f71245bf3f59421a959cf6b2f57e7d28c7dbec9a61e7416747c2d79b96
\ No newline at end of file

From f630ea332358a9968a944bb5ed203364f58b781d Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Mon, 12 Jun 2023 11:53:30 +0200
Subject: [PATCH 16/18] python shall output to rerun_py/rerun_sdk/rerun2

---
 crates/re_types/build.rs        | 2 +-
 crates/re_types/source_hash.txt | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/crates/re_types/build.rs b/crates/re_types/build.rs
index 687d7507d590..82c328e0aa4b 100644
--- a/crates/re_types/build.rs
+++ b/crates/re_types/build.rs
@@ -15,7 +15,7 @@ use re_build_tools::{
 const SOURCE_HASH_PATH: &str = "./source_hash.txt";
 const DEFINITIONS_DIR_PATH: &str = "./definitions";
 const RUST_OUTPUT_DIR_PATH: &str = ".";
-const PYTHON_OUTPUT_DIR_PATH: &str = "../../rerun_py/rerun2";
+const PYTHON_OUTPUT_DIR_PATH: &str = "../../rerun_py/rerun_sdk/rerun2";
 
 fn main() {
     if std::env::var("CI").is_ok() {
diff --git a/crates/re_types/source_hash.txt b/crates/re_types/source_hash.txt
index 45db6bc3ce6b..1096244fad32 100644
--- a/crates/re_types/source_hash.txt
+++ b/crates/re_types/source_hash.txt
@@ -1,4 +1,4 @@
 # This is a sha256 hash for all direct and indirect dependencies of this crate's build script.
 # It can be safely removed at anytime to force the build script to run again.
 # Check out build.rs to see how it's computed.
-5a4275f71245bf3f59421a959cf6b2f57e7d28c7dbec9a61e7416747c2d79b96
\ No newline at end of file
+e264658cf8184bcb9dbd1302910072b755ea7901e6337b3b5394094ca67e0ef7
\ No newline at end of file

From fb864663039ce0bd6798ff95c848626988ca9245 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Wed, 14 Jun 2023 11:04:32 +0200
Subject: [PATCH 17/18] addressing PR comments

---
 crates/re_types/Cargo.toml                       | 2 +-
 crates/re_types/definitions/arrow/attributes.fbs | 6 ++++--
 crates/re_types/definitions/fbs/attributes.fbs   | 2 +-
 crates/re_types/definitions/fbs/scalars.fbs      | 3 +++
 crates/re_types/source_hash.txt                  | 2 +-
 5 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/crates/re_types/Cargo.toml b/crates/re_types/Cargo.toml
index e3b1b9dc1b2a..4da294c84c50 100644
--- a/crates/re_types/Cargo.toml
+++ b/crates/re_types/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "re_types"
 authors.workspace = true
-description = "The standard Rerun data types, component types, and archetypes."
+description = "The built-in Rerun data types, component types, and archetypes."
 edition.workspace = true
 homepage.workspace = true
 include.workspace = true
diff --git a/crates/re_types/definitions/arrow/attributes.fbs b/crates/re_types/definitions/arrow/attributes.fbs
index 33c81c7dfb59..f8e96e4d8bad 100644
--- a/crates/re_types/definitions/arrow/attributes.fbs
+++ b/crates/re_types/definitions/arrow/attributes.fbs
@@ -2,14 +2,16 @@ namespace arrow;
 
 /// Marks a union as sparse, affecting its Arrow datatype.
 ///
-/// This does _not_ affect the object generated in Python or Rust, this is a pure Arrow concern!
+/// This does _not_ affect the generated object structure in and of itself, it is a pure Arrow
+/// matter that only impacts (de)serialization.
 ///
 /// Only applies to unions.
 attribute "arrow.attr.sparse_union";
 
 /// Marks a single-field object as transparent, affecting its Arrow datatype.
 ///
-/// This does _not_ affect the object generated in Python or Rust, this is a pure Arrow concern!
+/// This does _not_ affect the generated object structure in and of itself, it is a pure Arrow
+/// matter that only impacts (de)serialization.
 ///
 /// This is generally most useful for getting rid of extraneous `struct` layers.
 attribute "arrow.attr.transparent";
diff --git a/crates/re_types/definitions/fbs/attributes.fbs b/crates/re_types/definitions/fbs/attributes.fbs
index cdf311181ef6..d431691e8d96 100644
--- a/crates/re_types/definitions/fbs/attributes.fbs
+++ b/crates/re_types/definitions/fbs/attributes.fbs
@@ -6,7 +6,7 @@ namespace fbs.attributes;
 /// This defines a stable order between objects of the same kind, e.g. the order in which fields of a
 /// struct should be laid out when generating code.
 /// This is always required since flatbuffers works entirely with unordered maps internally, which
-/// would results in flaky code generation.
+/// would result in flaky code generation.
 ///
 /// In unions, this effectively defines the arrow tag of each variant, since the tag depends on the
 /// fields's order in the datatype!
diff --git a/crates/re_types/definitions/fbs/scalars.fbs b/crates/re_types/definitions/fbs/scalars.fbs
index bb6fcd75063b..085df42e26db 100644
--- a/crates/re_types/definitions/fbs/scalars.fbs
+++ b/crates/re_types/definitions/fbs/scalars.fbs
@@ -2,6 +2,9 @@
 /// first.
 /// This package provides pre-wrapped scalars that will be automatically flattened down to their
 /// inner type by our parsers.
+///
+/// Look e.g. for `fbs.scalars.Float32` in `objects.rs` to see this flatenning in action.
+
 namespace fbs.scalars;
 
 /// Flattens down to a 32-bit float.
diff --git a/crates/re_types/source_hash.txt b/crates/re_types/source_hash.txt
index 1096244fad32..a5681461859d 100644
--- a/crates/re_types/source_hash.txt
+++ b/crates/re_types/source_hash.txt
@@ -1,4 +1,4 @@
 # This is a sha256 hash for all direct and indirect dependencies of this crate's build script.
 # It can be safely removed at anytime to force the build script to run again.
 # Check out build.rs to see how it's computed.
-e264658cf8184bcb9dbd1302910072b755ea7901e6337b3b5394094ca67e0ef7
\ No newline at end of file
+dae77f291d1698807cd865265cbb77731bd1aedf07c0968a6b0ac67c18f94590
\ No newline at end of file

From 8c78c010f5b6c3eafa203f02f570131641a1d4d9 Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Wed, 14 Jun 2023 16:33:20 +0200
Subject: [PATCH 18/18] git lost it

---
 Cargo.lock | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 306ba7d675c4..f6211650f901 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6681,21 +6681,6 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1dbabb1cbd15a1d6d12d9ed6b35cc6777d4af87ab3ba155ea37215f20beab80c"
 
-[[package]]
-name = "xshell"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "962c039b3a7b16cf4e9a4248397c6585c07547412e7d6a6e035389a802dcfe90"
-dependencies = [
- "xshell-macros",
-]
-
-[[package]]
-name = "xshell-macros"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1dbabb1cbd15a1d6d12d9ed6b35cc6777d4af87ab3ba155ea37215f20beab80c"
-
 [[package]]
 name = "xxhash-rust"
 version = "0.8.6"