feat(syntax_operations): add crate oxc_syntax_operations (#6202)

I intend to add constant folding and eval logic to this crate. There are downstream tools that require these functionalities alone.

It's also reasonable to move these traits out of the `ast` crate.

Cargo.toml

@@ -95,6 +95,7 @@ oxc_semantic = { version = "0.30.5", path = "crates/oxc_semantic" }
 oxc_sourcemap = { version = "0.30.5", path = "crates/oxc_sourcemap" }
 oxc_span = { version = "0.30.5", path = "crates/oxc_span" }
 oxc_syntax = { version = "0.30.5", path = "crates/oxc_syntax" }
+oxc_syntax_operations = { version = "0.30.5", path = "crates/oxc_syntax_operations" }
 oxc_transform_napi = { version = "0.30.5", path = "napi/transform" }
 oxc_transformer = { version = "0.30.5", path = "crates/oxc_transformer" }
 oxc_traverse = { version = "0.30.5", path = "crates/oxc_traverse" }

crates/oxc_ast/src/ast_impl/js.rs

@@ -382,14 +382,6 @@ impl<'a> ArrayExpressionElement<'a> {
     }
 }
 
-impl<'a> ObjectExpression<'a> {
-    /// Returns `true` if this object has a property named `__proto__`
-    pub fn has_proto(&self) -> bool {
-        use crate::syntax_directed_operations::PropName;
-        self.properties.iter().any(|p| p.prop_name().is_some_and(|name| name.0 == "__proto__"))
-    }
-}
-
 impl<'a> PropertyKey<'a> {
     pub fn static_name(&self) -> Option<Cow<'a, str>> {
         match self {

crates/oxc_ast/src/lib.rs

@@ -33,7 +33,6 @@ mod ast_builder_impl;
 mod ast_impl;
 mod ast_kind_impl;
 pub mod precedence;
-pub mod syntax_directed_operations;
 mod trivia;
 
 mod generated {

crates/oxc_isolated_declarations/Cargo.toml

@@ -29,6 +29,7 @@ oxc_ast = { workspace = true }
 oxc_diagnostics = { workspace = true }
 oxc_span = { workspace = true }
 oxc_syntax = { workspace = true, features = ["to_js_string"] }
+oxc_syntax_operations = { workspace = true }
 
 bitflags = { workspace = true }
 rustc-hash = { workspace = true }

crates/oxc_isolated_declarations/src/declaration.rs

@@ -6,9 +6,10 @@ use oxc_allocator::Vec;
 #[allow(clippy::wildcard_imports)]
 use oxc_ast::ast::*;
 use oxc_ast::visit::walk_mut::walk_ts_signatures;
-use oxc_ast::{syntax_directed_operations::BoundNames, Visit, VisitMut};
+use oxc_ast::{Visit, VisitMut};
 use oxc_span::{GetSpan, SPAN};
 use oxc_syntax::scope::ScopeFlags;
+use oxc_syntax_operations::BoundNames;
 
 use crate::diagnostics::accessor_must_have_explicit_return_type;
 use crate::{

crates/oxc_minifier/Cargo.toml

@@ -29,6 +29,7 @@ oxc_parser = { workspace = true }
 oxc_semantic = { workspace = true }
 oxc_span = { workspace = true }
 oxc_syntax = { workspace = true }
+oxc_syntax_operations = { workspace = true }
 oxc_traverse = { workspace = true }
 
 cow-utils = { workspace = true }

crates/oxc_minifier/src/keep_var.rs

@@ -1,5 +1,6 @@
-use oxc_ast::{ast::*, syntax_directed_operations::BoundNames, AstBuilder, Visit, NONE};
+use oxc_ast::{ast::*, AstBuilder, Visit, NONE};
 use oxc_span::{Atom, Span, SPAN};
+use oxc_syntax_operations::BoundNames;
 
 pub struct KeepVar<'a> {
     ast: AstBuilder<'a>,

crates/oxc_module_lexer/Cargo.toml

@@ -23,6 +23,7 @@ doctest = false
 [dependencies]
 oxc_ast = { workspace = true }
 oxc_span = { workspace = true }
+oxc_syntax_operations = { workspace = true }
 
 [dev-dependencies]
 oxc_allocator = { workspace = true }

crates/oxc_module_lexer/src/lib.rs

@@ -7,8 +7,9 @@ use oxc_ast::visit::walk::{
     walk_import_expression, walk_meta_property, walk_module_declaration, walk_statement,
 };
 #[allow(clippy::wildcard_imports)]
-use oxc_ast::{ast::*, syntax_directed_operations::BoundNames, Visit};
+use oxc_ast::{ast::*, Visit};
 use oxc_span::{Atom, GetSpan};
+use oxc_syntax_operations::BoundNames;
 
 #[derive(Debug, Clone)]
 pub struct ImportSpecifier<'a> {

crates/oxc_parser/Cargo.toml

@@ -25,6 +25,7 @@ oxc_diagnostics = { workspace = true }
 oxc_regular_expression = { workspace = true }
 oxc_span = { workspace = true }
 oxc_syntax = { workspace = true }
+oxc_syntax_operations = { workspace = true }
 
 assert-unchecked = { workspace = true }
 bitflags = { workspace = true }

crates/oxc_parser/src/js/class.rs

@@ -1,7 +1,8 @@
 use oxc_allocator::{Box, Vec};
-use oxc_ast::{ast::*, syntax_directed_operations::PropName};
+use oxc_ast::ast::*;
 use oxc_diagnostics::Result;
 use oxc_span::{GetSpan, Span};
+use oxc_syntax_operations::PropName;
 
 use crate::{
     diagnostics,

crates/oxc_semantic/Cargo.toml

@@ -26,6 +26,7 @@ oxc_diagnostics = { workspace = true }
 oxc_index = { workspace = true }
 oxc_span = { workspace = true }
 oxc_syntax = { workspace = true }
+oxc_syntax_operations = { workspace = true }
 
 assert-unchecked = { workspace = true }
 indexmap = { workspace = true }

crates/oxc_semantic/src/binder.rs

@@ -3,12 +3,9 @@
 use std::{borrow::Cow, ptr};
 
 #[allow(clippy::wildcard_imports)]
-use oxc_ast::{
-    ast::*,
-    syntax_directed_operations::{BoundNames, IsSimpleParameterList},
-    AstKind,
-};
+use oxc_ast::{ast::*, AstKind};
 use oxc_span::{GetSpan, SourceType};
+use oxc_syntax_operations::{BoundNames, IsSimpleParameterList};
 
 use crate::{
     scope::{ScopeFlags, ScopeId},

crates/oxc_semantic/src/checker/javascript.rs

@@ -2,18 +2,15 @@ use phf::{phf_set, Set};
 use rustc_hash::FxHashMap;
 
 #[allow(clippy::wildcard_imports)]
-use oxc_ast::{
-    ast::*,
-    syntax_directed_operations::{IsSimpleParameterList, PropName},
-    AstKind,
-};
+use oxc_ast::{ast::*, AstKind};
 use oxc_diagnostics::{LabeledSpan, OxcDiagnostic};
 use oxc_span::{GetSpan, ModuleKind, Span};
 use oxc_syntax::{
     module_record::ExportLocalName,
     number::NumberBase,
     operator::{AssignmentOperator, BinaryOperator, LogicalOperator, UnaryOperator},
 };
+use oxc_syntax_operations::{IsSimpleParameterList, PropName};
 
 use crate::{builder::SemanticBuilder, diagnostics::redeclaration, scope::ScopeFlags, AstNode};
 

crates/oxc_semantic/src/checker/typescript.rs

@@ -3,13 +3,10 @@ use std::borrow::Cow;
 use rustc_hash::FxHashMap;
 
 #[allow(clippy::wildcard_imports)]
-use oxc_ast::{
-    ast::*,
-    syntax_directed_operations::{BoundNames, PropName},
-    AstKind,
-};
+use oxc_ast::{ast::*, AstKind};
 use oxc_diagnostics::OxcDiagnostic;
 use oxc_span::{Atom, GetSpan, Span};
+use oxc_syntax_operations::{BoundNames, PropName};
 
 use crate::{builder::SemanticBuilder, diagnostics::redeclaration};
 

crates/oxc_semantic/src/module_record/builder.rs

@@ -1,10 +1,11 @@
 use std::path::PathBuf;
 
 #[allow(clippy::wildcard_imports)]
-use oxc_ast::{ast::*, syntax_directed_operations::BoundNames};
+use oxc_ast::ast::*;
 use oxc_span::{CompactStr, GetSpan, Span};
 #[allow(clippy::wildcard_imports)]
 use oxc_syntax::module_record::*;
+use oxc_syntax_operations::BoundNames;
 
 #[derive(Default)]
 pub struct ModuleRecordBuilder {

crates/oxc_syntax_operations/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "oxc_syntax_operations"
+version = "0.30.5"
+authors.workspace = true
+categories.workspace = true
+edition.workspace = true
+homepage.workspace = true
+include = ["/src"]
+keywords.workspace = true
+license.workspace = true
+publish = true
+repository.workspace = true
+rust-version.workspace = true
+description.workspace = true
+
+[lints]
+workspace = true
+
+[lib]
+test = false
+doctest = false
+
+[dependencies]
+oxc_ast = { workspace = true }
+oxc_span = { workspace = true }

crates/oxc_ast/src/syntax_directed_operations/bound_names.rs → crates/oxc_syntax_operations/src/bound_names.rs

@@ -1,4 +1,9 @@
-use crate::ast::*;
+use oxc_ast::ast::{
+    ArrayPattern, AssignmentPattern, BindingIdentifier, BindingPattern, BindingPatternKind,
+    BindingRestElement, Class, Declaration, ExportNamedDeclaration, FormalParameter,
+    FormalParameters, Function, ImportDeclaration, ImportDeclarationSpecifier, ModuleDeclaration,
+    ObjectPattern, VariableDeclaration,
+};
 
 /// [`BoundName`](https://tc39.es/ecma262/#sec-static-semantics-boundnames)
 pub trait BoundName<'a> {

crates/oxc_syntax_operations/src/has_proto.rs

@@ -0,0 +1,14 @@
+use oxc_ast::ast::ObjectExpression;
+
+use crate::PropName;
+
+pub trait HasProto {
+    /// Returns `true` if this object has a property named `__proto__`
+    fn has_proto(&self) -> bool;
+}
+
+impl<'a> HasProto for ObjectExpression<'a> {
+    fn has_proto(&self) -> bool {
+        self.properties.iter().any(|p| p.prop_name().is_some_and(|name| name.0 == "__proto__"))
+    }
+}

crates/oxc_ast/src/syntax_directed_operations/is_simple_parameter_list.rs → crates/oxc_syntax_operations/src/is_simple_parameter_list.rs

@@ -1,4 +1,4 @@
-use crate::ast::*;
+use oxc_ast::ast::FormalParameters;
 
 /// [`IsSimpleParameterList`](https://tc39.es/ecma262/#sec-static-semantics-issimpleparameterlist)
 pub trait IsSimpleParameterList {

crates/oxc_syntax_operations/src/lib.rs

@@ -0,0 +1,20 @@
+//! Traits for JavaScript syntax operations
+//!
+//! * BoundNames
+//! * IsSimpleParameterList
+//! * PrivateBoundIdentifiers
+//! * PropName
+//! * Constant Folding
+//!
+//! See [ECMA262 Syntax-Directed Operations](https://tc39.es/ecma262/#sec-syntax-directed-operations)
+
+mod bound_names;
+mod has_proto;
+mod is_simple_parameter_list;
+mod private_bound_identifiers;
+mod prop_name;
+
+pub use self::{
+    bound_names::BoundNames, has_proto::HasProto, is_simple_parameter_list::IsSimpleParameterList,
+    private_bound_identifiers::PrivateBoundIdentifiers, prop_name::PropName,
+};

crates/oxc_ast/src/syntax_directed_operations/private_bound_identifiers.rs → crates/oxc_syntax_operations/src/private_bound_identifiers.rs

@@ -1,4 +1,7 @@
-use crate::ast::*;
+use oxc_ast::ast::{
+    AccessorProperty, ClassElement, MethodDefinition, PrivateIdentifier, PropertyDefinition,
+    PropertyKey,
+};
 
 /// [`PrivateBoundIdentifiers`](https://tc39.es/ecma262/#sec-static-semantics-privateboundidentifiers)
 pub trait PrivateBoundIdentifiers {

crates/oxc_ast/src/syntax_directed_operations/prop_name.rs → crates/oxc_syntax_operations/src/prop_name.rs

@@ -1,7 +1,9 @@
+use oxc_ast::ast::{
+    ClassElement, MethodDefinition, ObjectProperty, ObjectPropertyKind, PropertyDefinition,
+    PropertyKey, PropertyKind,
+};
 use oxc_span::Span;
 
-use crate::ast::*;
-
 /// [`PropName`](https://tc39.es/ecma262/#sec-static-semantics-propname)
 pub trait PropName {
     fn prop_name(&self) -> Option<(&str, Span)>;

crates/oxc_transformer/Cargo.toml

@@ -35,6 +35,7 @@ oxc_regular_expression = { workspace = true }
 oxc_semantic = { workspace = true }
 oxc_span = { workspace = true }
 oxc_syntax = { workspace = true, features = ["to_js_string"] }
+oxc_syntax_operations = { workspace = true }
 oxc_traverse = { workspace = true }
 ropey = { workspace = true }
 rustc-hash = { workspace = true }

crates/oxc_transformer/src/react/jsx.rs

@@ -97,6 +97,7 @@ use oxc_syntax::{
     symbol::SymbolFlags,
     xml_entities::XML_ENTITIES,
 };
+use oxc_syntax_operations::HasProto;
 use oxc_traverse::{BoundIdentifier, Traverse, TraverseCtx};
 
 use crate::{common::module_imports::NamedImport, TransformCtx};

crates/oxc_transformer/src/typescript/namespace.rs

@@ -1,12 +1,14 @@
 use oxc_allocator::{Box, Vec};
-use oxc_ast::{ast::*, syntax_directed_operations::BoundNames, NONE};
+use oxc_ast::{ast::*, NONE};
 use oxc_span::{Atom, CompactStr, SPAN};
 use oxc_syntax::{
     operator::{AssignmentOperator, LogicalOperator},
     scope::{ScopeFlags, ScopeId},
     symbol::SymbolFlags,
 };
+use oxc_syntax_operations::BoundNames;
 use oxc_traverse::{Traverse, TraverseCtx};
+
 use rustc_hash::FxHashSet;
 
 use super::{

crates/oxc_traverse/Cargo.toml

@@ -29,6 +29,7 @@ oxc_data_structures = { workspace = true }
 oxc_semantic = { workspace = true }
 oxc_span = { workspace = true }
 oxc_syntax = { workspace = true }
+oxc_syntax_operations = { workspace = true }
 
 compact_str = { workspace = true }
 itoa = { workspace = true }