Add a mutable visitor (#782)

* Add a mutable visitor

This adds the ability to mutate parsed sql queries.
Previously, only visitors taking an immutable reference to the visited structures were allowed.

* add utility functions for mutable visits

* bump version numbers

Cargo.toml

@@ -33,7 +33,7 @@ serde = { version = "1.0", features = ["derive"], optional = true }
 # of dev-dependencies because of
 # https://github.com/rust-lang/cargo/issues/1596
 serde_json = { version = "1.0", optional = true }
-sqlparser_derive = { version = "0.1", path = "derive", optional = true }
+sqlparser_derive = { version = "0.1.1", path = "derive", optional = true }
 
 [dev-dependencies]
 simple_logger = "4.0"

derive/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "sqlparser_derive"
 description = "proc macro for sqlparser"
-version = "0.1.0"
+version = "0.1.1"
 authors = ["sqlparser-rs authors"]
 homepage = "https://github.com/sqlparser-rs/sqlparser-rs"
 documentation = "https://docs.rs/sqlparser_derive/"

derive/README.md

@@ -6,13 +6,13 @@ This crate contains a procedural macro that can automatically derive
 implementations of the `Visit` trait in the [sqlparser](https://crates.io/crates/sqlparser) crate
 
 ```rust
-#[derive(Visit)]
+#[derive(Visit, VisitMut)]
 struct Foo {
     boolean: bool,
     bar: Bar,
 }
 
-#[derive(Visit)]
+#[derive(Visit, VisitMut)]
 enum Bar {
     A(),
     B(String, bool),
@@ -51,7 +51,7 @@ impl Visit for Bar {
 Additionally certain types may wish to call a corresponding method on visitor before recursing
 
 ```rust
-#[derive(Visit)]
+#[derive(Visit, VisitMut)]
 #[visit(with = "visit_expr")]
 enum Expr {
     A(),

derive/src/lib.rs

@@ -6,25 +6,58 @@ use syn::{
     Ident, Index, Lit, Meta, MetaNameValue, NestedMeta,
 };
 
+
+/// Implementation of `[#derive(Visit)]`
+#[proc_macro_derive(VisitMut, attributes(visit))]
+pub fn derive_visit_mut(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    derive_visit(input, &VisitType {
+        visit_trait: quote!(VisitMut),
+        visitor_trait: quote!(VisitorMut),
+        modifier: Some(quote!(mut)),
+    })
+}
+
 /// Implementation of `[#derive(Visit)]`
 #[proc_macro_derive(Visit, attributes(visit))]
-pub fn derive_visit(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+pub fn derive_visit_immutable(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    derive_visit(input, &VisitType {
+        visit_trait: quote!(Visit),
+        visitor_trait: quote!(Visitor),
+        modifier: None,
+    })
+}
+
+struct VisitType {
+    visit_trait: TokenStream,
+    visitor_trait: TokenStream,
+    modifier: Option<TokenStream>,
+}
+
+fn derive_visit(
+    input: proc_macro::TokenStream,
+    visit_type: &VisitType,
+) -> proc_macro::TokenStream {
     // Parse the input tokens into a syntax tree.
     let input = parse_macro_input!(input as DeriveInput);
     let name = input.ident;
 
+    let VisitType { visit_trait, visitor_trait, modifier } = visit_type;
+
     let attributes = Attributes::parse(&input.attrs);
-    // Add a bound `T: HeapSize` to every type parameter T.
-    let generics = add_trait_bounds(input.generics);
+    // Add a bound `T: Visit` to every type parameter T.
+    let generics = add_trait_bounds(input.generics, visit_type);
     let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
 
     let (pre_visit, post_visit) = attributes.visit(quote!(self));
-    let children = visit_children(&input.data);
+    let children = visit_children(&input.data, visit_type);
 
     let expanded = quote! {
         // The generated impl.
-        impl #impl_generics sqlparser::ast::Visit for #name #ty_generics #where_clause {
-            fn visit<V: sqlparser::ast::Visitor>(&self, visitor: &mut V) -> ::std::ops::ControlFlow<V::Break> {
+        impl #impl_generics sqlparser::ast::#visit_trait for #name #ty_generics #where_clause {
+            fn visit<V: sqlparser::ast::#visitor_trait>(
+                &#modifier self,
+                visitor: &mut V
+            ) -> ::std::ops::ControlFlow<V::Break> {
                 #pre_visit
                 #children
                 #post_visit
@@ -92,25 +125,25 @@ impl Attributes {
 }
 
 // Add a bound `T: Visit` to every type parameter T.
-fn add_trait_bounds(mut generics: Generics) -> Generics {
+fn add_trait_bounds(mut generics: Generics, VisitType{visit_trait, ..}: &VisitType) -> Generics {
     for param in &mut generics.params {
         if let GenericParam::Type(ref mut type_param) = *param {
-            type_param.bounds.push(parse_quote!(sqlparser::ast::Visit));
+            type_param.bounds.push(parse_quote!(sqlparser::ast::#visit_trait));
         }
     }
     generics
 }
 
 // Generate the body of the visit implementation for the given type
-fn visit_children(data: &Data) -> TokenStream {
+fn visit_children(data: &Data, VisitType{visit_trait, modifier, ..}: &VisitType) -> TokenStream {
     match data {
         Data::Struct(data) => match &data.fields {
             Fields::Named(fields) => {
                 let recurse = fields.named.iter().map(|f| {
                     let name = &f.ident;
                     let attributes = Attributes::parse(&f.attrs);
-                    let (pre_visit, post_visit) = attributes.visit(quote!(&self.#name));
-                    quote_spanned!(f.span() => #pre_visit sqlparser::ast::Visit::visit(&self.#name, visitor)?; #post_visit)
+                    let (pre_visit, post_visit) = attributes.visit(quote!(&#modifier self.#name));
+                    quote_spanned!(f.span() => #pre_visit sqlparser::ast::#visit_trait::visit(&#modifier self.#name, visitor)?; #post_visit)
                 });
                 quote! {
                     #(#recurse)*
@@ -121,7 +154,7 @@ fn visit_children(data: &Data) -> TokenStream {
                     let index = Index::from(i);
                     let attributes = Attributes::parse(&f.attrs);
                     let (pre_visit, post_visit) = attributes.visit(quote!(&self.#index));
-                    quote_spanned!(f.span() => #pre_visit sqlparser::ast::Visit::visit(&self.#index, visitor)?; #post_visit)
+                    quote_spanned!(f.span() => #pre_visit sqlparser::ast::#visit_trait::visit(&#modifier self.#index, visitor)?; #post_visit)
                 });
                 quote! {
                     #(#recurse)*
@@ -140,8 +173,8 @@ fn visit_children(data: &Data) -> TokenStream {
                         let visit = fields.named.iter().map(|f| {
                             let name = &f.ident;
                             let attributes = Attributes::parse(&f.attrs);
-                            let (pre_visit, post_visit) = attributes.visit(quote!(&#name));
-                            quote_spanned!(f.span() => #pre_visit sqlparser::ast::Visit::visit(#name, visitor)?; #post_visit)
+                            let (pre_visit, post_visit) = attributes.visit(name.to_token_stream());
+                            quote_spanned!(f.span() => #pre_visit sqlparser::ast::#visit_trait::visit(#name, visitor)?; #post_visit)
                         });
 
                         quote!(
@@ -155,8 +188,8 @@ fn visit_children(data: &Data) -> TokenStream {
                         let visit = fields.unnamed.iter().enumerate().map(|(i, f)| {
                             let name = format_ident!("_{}", i);
                             let attributes = Attributes::parse(&f.attrs);
-                            let (pre_visit, post_visit) = attributes.visit(quote!(&#name));
-                            quote_spanned!(f.span() => #pre_visit sqlparser::ast::Visit::visit(#name, visitor)?; #post_visit)
+                            let (pre_visit, post_visit) = attributes.visit(name.to_token_stream());
+                            quote_spanned!(f.span() => #pre_visit sqlparser::ast::#visit_trait::visit(#name, visitor)?; #post_visit)
                         });
 
                         quote! {

src/ast/data_type.rs

@@ -18,7 +18,7 @@ use core::fmt;
 use serde::{Deserialize, Serialize};
 
 #[cfg(feature = "visitor")]
-use sqlparser_derive::Visit;
+use sqlparser_derive::{Visit, VisitMut};
 
 use crate::ast::ObjectName;
 
@@ -27,7 +27,7 @@ use super::value::escape_single_quote_string;
 /// SQL data types
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum DataType {
     /// Fixed-length character type e.g. CHARACTER(10)
     Character(Option<CharacterLength>),
@@ -341,7 +341,7 @@ fn format_datetime_precision_and_tz(
 /// guarantee compatibility with the input query we must maintain its exact information.
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum TimezoneInfo {
     /// No information about time zone. E.g., TIMESTAMP
     None,
@@ -389,7 +389,7 @@ impl fmt::Display for TimezoneInfo {
 /// [standard]: https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html#exact-numeric-type
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum ExactNumberInfo {
     /// No additional information e.g. `DECIMAL`
     None,
@@ -420,7 +420,7 @@ impl fmt::Display for ExactNumberInfo {
 /// [1]: https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html#character-length
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub struct CharacterLength {
     /// Default (if VARYING) or maximum (if not VARYING) length
     pub length: u64,
@@ -443,7 +443,7 @@ impl fmt::Display for CharacterLength {
 /// [1]: https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html#char-length-units
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum CharLengthUnits {
     /// CHARACTERS unit
     Characters,

src/ast/ddl.rs

@@ -21,7 +21,7 @@ use core::fmt;
 use serde::{Deserialize, Serialize};
 
 #[cfg(feature = "visitor")]
-use sqlparser_derive::Visit;
+use sqlparser_derive::{Visit, VisitMut};
 
 use crate::ast::value::escape_single_quote_string;
 use crate::ast::{display_comma_separated, display_separated, DataType, Expr, Ident, ObjectName};
@@ -30,7 +30,7 @@ use crate::tokenizer::Token;
 /// An `ALTER TABLE` (`Statement::AlterTable`) operation
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum AlterTableOperation {
     /// `ADD <table_constraint>`
     AddConstraint(TableConstraint),
@@ -100,7 +100,7 @@ pub enum AlterTableOperation {
 
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum AlterIndexOperation {
     RenameIndex { index_name: ObjectName },
 }
@@ -224,7 +224,7 @@ impl fmt::Display for AlterIndexOperation {
 /// An `ALTER COLUMN` (`Statement::AlterTable`) operation
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum AlterColumnOperation {
     /// `SET NOT NULL`
     SetNotNull,
@@ -268,7 +268,7 @@ impl fmt::Display for AlterColumnOperation {
 /// `ALTER TABLE ADD <constraint>` statement.
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum TableConstraint {
     /// `[ CONSTRAINT <name> ] { PRIMARY KEY | UNIQUE } (<columns>)`
     Unique {
@@ -433,7 +433,7 @@ impl fmt::Display for TableConstraint {
 /// [1]: https://dev.mysql.com/doc/refman/8.0/en/create-table.html
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum KeyOrIndexDisplay {
     /// Nothing to display
     None,
@@ -469,7 +469,7 @@ impl fmt::Display for KeyOrIndexDisplay {
 /// [3]: https://www.postgresql.org/docs/14/sql-createindex.html
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum IndexType {
     BTree,
     Hash,
@@ -488,7 +488,7 @@ impl fmt::Display for IndexType {
 /// SQL column definition
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub struct ColumnDef {
     pub name: Ident,
     pub data_type: DataType,
@@ -524,7 +524,7 @@ impl fmt::Display for ColumnDef {
 /// "column options," and we allow any column option to be named.
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub struct ColumnOptionDef {
     pub name: Option<Ident>,
     pub option: ColumnOption,
@@ -540,7 +540,7 @@ impl fmt::Display for ColumnOptionDef {
 /// TABLE` statement.
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum ColumnOption {
     /// `NULL`
     Null,
@@ -630,7 +630,7 @@ fn display_constraint_name(name: &'_ Option<Ident>) -> impl fmt::Display + '_ {
 /// Used in foreign key constraints in `ON UPDATE` and `ON DELETE` options.
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum ReferentialAction {
     Restrict,
     Cascade,

src/ast/helpers/stmt_create_table.rs

@@ -5,7 +5,7 @@ use alloc::{boxed::Box, format, string::String, vec, vec::Vec};
 use serde::{Deserialize, Serialize};
 
 #[cfg(feature = "visitor")]
-use sqlparser_derive::Visit;
+use sqlparser_derive::{Visit, VisitMut};
 
 use crate::ast::{
     ColumnDef, FileFormat, HiveDistributionStyle, HiveFormat, ObjectName, OnCommit, Query,
@@ -43,7 +43,7 @@ use crate::parser::ParserError;
 /// [1]: crate::ast::Statement::CreateTable
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[cfg_attr(feature = "visitor", derive(Visit))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub struct CreateTableBuilder {
     pub or_replace: bool,
     pub temporary: bool,