feat: add parser registry and custom format support

crates/vectorless-compiler/src/config.rs

@@ -18,14 +18,16 @@ use vectorless_utils::fingerprint::{Fingerprint, Fingerprinter};
 use std::path::PathBuf;
 
 /// Index mode for document processing.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum SourceFormat {
     /// Auto-detect format from file extension.
     Auto,
     /// Force Markdown format.
     Markdown,
     /// Force PDF format.
     Pdf,
+    /// Custom format resolved via [`ParserRegistry`](crate::parse::ParserRegistry).
+    Custom(String),
 }
 
 impl Default for SourceFormat {

crates/vectorless-compiler/src/lib.rs

@@ -67,6 +67,9 @@ pub mod summary;
 // Re-export main types from pipeline
 pub use pipeline::{CompileMetrics, CompileResult, CompilerInput, PipelineExecutor};
 
+// Re-export parser plugin types
+pub use parse::{Parser, ParserRegistry};
+
 // Re-export config types
 pub use config::{PipelineOptions, SourceFormat, ThinningConfig};
 pub use vectorless_document::ReasoningIndexConfig;

crates/vectorless-compiler/src/parse/markdown/mod.rs

@@ -26,3 +26,46 @@ mod frontmatter;
 mod parser;
 
 pub use parser::MarkdownParser;
+
+use crate::parse::{ParseResult, Parser};
+use std::path::Path;
+use vectorless_error::Result;
+
+/// [`Parser`] trait adapter for [`MarkdownParser`].
+pub struct MarkdownParserAdapter {
+    inner: MarkdownParser,
+}
+
+impl MarkdownParserAdapter {
+    /// Create a new Markdown parser adapter.
+    pub fn new() -> Self {
+        Self {
+            inner: MarkdownParser::new(),
+        }
+    }
+}
+
+#[async_trait::async_trait]
+impl Parser for MarkdownParserAdapter {
+    fn name(&self) -> &str {
+        "markdown"
+    }
+
+    fn extensions(&self) -> &[&str] {
+        &["md", "markdown"]
+    }
+
+    async fn parse_content(&self, content: &str) -> Result<ParseResult> {
+        self.inner.parse(content).await
+    }
+
+    async fn parse_file(&self, path: &Path) -> Result<ParseResult> {
+        self.inner.parse_file(path).await
+    }
+
+    async fn parse_bytes(&self, data: &[u8]) -> Result<ParseResult> {
+        let content = std::str::from_utf8(data)
+            .map_err(|e| vectorless_error::Error::Parse(format!("Invalid UTF-8: {}", e)))?;
+        self.inner.parse(content).await
+    }
+}

crates/vectorless-compiler/src/parse/mod.rs

@@ -3,8 +3,26 @@
 
 //! Document parsing for the compile pipeline.
 //!
-//! Supports Markdown and PDF formats. Parsing is dispatched directly
-//! via `match` — no trait objects or registry needed.
+//! Supports Markdown and PDF formats out of the box. Custom parsers can be
+//! added via the [`Parser`] trait and [`ParserRegistry`].
+//!
+//! # Adding a custom parser
+//!
+//! ```rust,ignore
+//! use vectorless_compiler::parse::{Parser, ParseResult, ParserRegistry};
+//!
+//! struct MyParser;
+//!
+//! #[async_trait]
+//! impl Parser for MyParser {
+//!     fn name(&self) -> &str { "my-format" }
+//!     fn extensions(&self) -> &[&str] { &["foo", "bar"] }
+//!     async fn parse_content(&self, content: &str) -> Result<ParseResult> { ... }
+//!     async fn parse_file(&self, path: &Path) -> Result<ParseResult> { ... }
+//! }
+//!
+//! let registry = ParserRegistry::default_parsers(None).with(MyParser);
+//! ```
 
 pub mod markdown;
 pub mod pdf;
@@ -14,12 +32,134 @@ pub mod types;
 // Re-export core types at module level
 pub use types::{DocumentFormat, DocumentMeta, ParseResult, RawNode};
 
+use std::collections::HashMap;
 use std::path::Path;
 
 use crate::parse::markdown::MarkdownParser;
 use vectorless_error::Result;
 use vectorless_llm::LlmClient;
 
+// ---------------------------------------------------------------------------
+// Parser trait
+// ---------------------------------------------------------------------------
+
+/// Trait for document format parsers.
+///
+/// Implement this to add support for a new document format.
+/// Register via [`ParserRegistry::register`] or [`ParserRegistry::with`].
+#[async_trait::async_trait]
+pub trait Parser: Send + Sync {
+    /// Parser name (e.g., "markdown", "pdf", "code").
+    fn name(&self) -> &str;
+
+    /// File extensions this parser handles, without dot (e.g., `["py", "rs"]`).
+    fn extensions(&self) -> &[&str] {
+        &[]
+    }
+
+    /// Parse string content into raw nodes.
+    async fn parse_content(&self, content: &str) -> Result<ParseResult>;
+
+    /// Parse a file into raw nodes.
+    async fn parse_file(&self, path: &Path) -> Result<ParseResult>;
+
+    /// Parse binary data into raw nodes.
+    async fn parse_bytes(&self, data: &[u8]) -> Result<ParseResult> {
+        let _ = data;
+        Err(vectorless_error::Error::Parse(
+            "Binary parsing not supported by this parser".into(),
+        ))
+    }
+}
+
+// ---------------------------------------------------------------------------
+// ParserRegistry
+// ---------------------------------------------------------------------------
+
+/// Registry of document format parsers.
+///
+/// Maps parser names and file extensions to [`Parser`] implementations.
+/// Built-in parsers for Markdown and PDF are provided by [`ParserRegistry::default_parsers`].
+pub struct ParserRegistry {
+    parsers: HashMap<String, Box<dyn Parser>>,
+    extension_map: HashMap<String, String>,
+}
+
+impl ParserRegistry {
+    /// Create an empty registry.
+    pub fn new() -> Self {
+        Self {
+            parsers: HashMap::new(),
+            extension_map: HashMap::new(),
+        }
+    }
+
+    /// Register a parser. Extensions declared by the parser are auto-indexed.
+    pub fn register(&mut self, parser: impl Parser + 'static) {
+        let name = parser.name().to_string();
+        for ext in parser.extensions() {
+            self.extension_map.insert(ext.to_lowercase(), name.clone());
+        }
+        self.parsers.insert(name, Box::new(parser));
+    }
+
+    /// Builder-style registration.
+    pub fn with(mut self, parser: impl Parser + 'static) -> Self {
+        self.register(parser);
+        self
+    }
+
+    /// Get a parser by name.
+    pub fn get(&self, name: &str) -> Option<&dyn Parser> {
+        self.parsers.get(name).map(|p| p.as_ref())
+    }
+
+    /// Get a parser by file extension (lowercase).
+    pub fn get_by_extension(&self, ext: &str) -> Option<&dyn Parser> {
+        self.extension_map
+            .get(&ext.to_lowercase())
+            .and_then(|name| self.parsers.get(name))
+            .map(|p| p.as_ref())
+    }
+
+    /// Default registry with built-in Markdown + PDF parsers.
+    pub fn default_parsers(llm_client: Option<LlmClient>) -> Self {
+        let mut registry = Self::new();
+        registry.register(markdown::MarkdownParserAdapter::new());
+        registry.register(pdf::PdfParserAdapter::new(llm_client));
+        registry
+    }
+
+    /// List all registered parser names.
+    pub fn parser_names(&self) -> Vec<&str> {
+        self.parsers.keys().map(|s| s.as_str()).collect()
+    }
+
+    /// List all supported file extensions (lowercase, no dot).
+    pub fn supported_extensions(&self) -> Vec<&str> {
+        self.extension_map.keys().map(|s| s.as_str()).collect()
+    }
+}
+
+impl Default for ParserRegistry {
+    fn default() -> Self {
+        Self::default_parsers(None)
+    }
+}
+
+impl std::fmt::Debug for ParserRegistry {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ParserRegistry")
+            .field("parsers", &self.parsers.keys().collect::<Vec<_>>())
+            .field("extensions", &self.extension_map)
+            .finish()
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Legacy free functions (backward compat — delegate to default registry)
+// ---------------------------------------------------------------------------
+
 /// Parse a string content document.
 pub async fn parse_content(
     content: &str,
@@ -34,6 +174,10 @@ pub async fn parse_content(
         DocumentFormat::Pdf => Err(vectorless_error::Error::Parse(
             "PDF requires bytes, not string content".to_string(),
         )),
+        _ => Err(vectorless_error::Error::Parse(format!(
+            "Unsupported format for content parsing: {:?}",
+            format
+        ))),
     }
 }
 
@@ -55,6 +199,10 @@ pub async fn parse_file(
             };
             parser.parse_file(path).await
         }
+        _ => Err(vectorless_error::Error::Parse(format!(
+            "Unsupported format for file parsing: {:?}",
+            format
+        ))),
     }
 }
 
@@ -79,6 +227,10 @@ pub async fn parse_bytes(
             };
             parser.parse_bytes_async(bytes, None).await
         }
+        _ => Err(vectorless_error::Error::Parse(format!(
+            "Unsupported format for bytes parsing: {:?}",
+            format
+        ))),
     }
 }
 

crates/vectorless-compiler/src/parse/pdf/mod.rs

@@ -27,3 +27,49 @@ mod types;
 
 pub use parser::PdfParser;
 pub use types::PdfPage;
+
+use crate::parse::{ParseResult, Parser};
+use std::path::Path;
+use vectorless_error::Result;
+use vectorless_llm::LlmClient;
+
+/// [`Parser`] trait adapter for [`PdfParser`].
+pub struct PdfParserAdapter {
+    inner: PdfParser,
+}
+
+impl PdfParserAdapter {
+    /// Create a PDF parser adapter, optionally with LLM support.
+    pub fn new(llm_client: Option<LlmClient>) -> Self {
+        let inner = match llm_client {
+            Some(client) => PdfParser::with_llm_client(client),
+            None => PdfParser::new(),
+        };
+        Self { inner }
+    }
+}
+
+#[async_trait::async_trait]
+impl Parser for PdfParserAdapter {
+    fn name(&self) -> &str {
+        "pdf"
+    }
+
+    fn extensions(&self) -> &[&str] {
+        &["pdf"]
+    }
+
+    async fn parse_content(&self, _content: &str) -> Result<ParseResult> {
+        Err(vectorless_error::Error::Parse(
+            "PDF requires bytes, not string content".into(),
+        ))
+    }
+
+    async fn parse_file(&self, path: &Path) -> Result<ParseResult> {
+        self.inner.parse_file(path).await
+    }
+
+    async fn parse_bytes(&self, data: &[u8]) -> Result<ParseResult> {
+        self.inner.parse_bytes_async(data, None).await
+    }
+}