Tree query language and engine

.changeset/curvy-donkeys-shout.md

@@ -0,0 +1,5 @@
+---
+"@nomicfoundation/slang": patch
+---
+
+Add tree query implementation as `Query::parse` and `Cursor::query`

Cargo.toml

@@ -80,6 +80,7 @@ napi = { version = "2.14.2", features = ["compat-mode", "napi8", "serde-json"] }
 napi-build = { version = "2.1.0" }
 napi-derive = { version = "2.14.6" }
 once_cell = { version = "1.19.0" }
+nom = { version = "7.1.3" }
 owo-colors = { version = "3.5.0", features = ["supports-colors"] }
 proc-macro2 = { version = "1.0.53" }
 quote = { version = "1.0.26" }
@@ -92,8 +93,9 @@ serde = { version = "1.0.158", features = ["derive", "rc"] }
 serde_json = { version = "1.0.94", features = ["preserve_order"] }
 serde_yaml = { version = "0.9.19" }
 similar-asserts = { version = "1.4.2" }
-strum = { version = "0.24.0" }
-strum_macros = { version = "0.24.0" }
+stack-graphs = { version = "0.12.0" }
+strum = { version = "0.25.0", features = ["phf"] }
+strum_macros = { version = "0.25.3" }
 syn = { version = "2.0.29", features = [
     "fold",
     "full",

crates/codegen/parser/generator/src/rust_generator.rs

@@ -131,6 +131,9 @@ impl RustGenerator {
             "lexer.rs",
             "parse_error.rs",
             "parse_output.rs",
+            "query_engine.rs",
+            "query_model.rs",
+            "query_parser.rs",
             "text_index.rs",
             "napi/napi_cst.rs",
             "napi/napi_cursor.rs",

crates/codegen/parser/runtime/Cargo.toml

@@ -15,6 +15,7 @@ napi-build = { workspace = true, optional = true }
 ariadne = { workspace = true }
 napi = { workspace = true, optional = true }
 napi-derive = { workspace = true, optional = true }
+nom = { workspace = true }
 serde = { workspace = true }
 strum = { workspace = true }
 strum_macros = { workspace = true }

crates/codegen/parser/runtime/src/cursor.rs

@@ -8,10 +8,10 @@ use crate::text_index::{TextIndex, TextRange};
 
 /// A [`PathNode`] that points to a [`RuleNode`].
 #[derive(Clone, Debug, PartialEq, Eq)]
-struct PathRuleNode {
-    rule_node: Rc<RuleNode>,
-    child_number: usize,
-    text_offset: TextIndex,
+pub(crate) struct PathRuleNode {
+    pub(super) rule_node: Rc<RuleNode>,
+    pub(super) child_number: usize,
+    pub(super) text_offset: TextIndex,
 }
 
 impl PathRuleNode {
@@ -26,14 +26,14 @@ impl PathRuleNode {
 
 /// A pointer to a [`Node`] in a CST, used by the [`Cursor`] to implement the traversal.
 #[derive(Clone, Debug, PartialEq, Eq)]
-struct PathNode {
+pub(crate) struct PathNode {
     /// The node the cursor is currently pointing to.
-    node: Node,
+    pub(super) node: Node,
     /// The index of the current child node in the parent's children.
     // Required to go to the next/previous sibling.
-    child_number: usize,
+    pub(super) child_number: usize,
     /// Text offset that corresponds to the beginning of the currently pointed to node.
-    text_offset: TextIndex,
+    pub(super) text_offset: TextIndex,
 }
 
 impl PathNode {
@@ -62,12 +62,12 @@ impl PathNode {
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Cursor {
     /// The list of ancestor rule nodes that the `current` node is a part of.
-    path: Vec<PathRuleNode>,
+    pub(super) path: Vec<PathRuleNode>,
     /// The node the cursor is currently pointing to.
-    current: PathNode,
+    pub(super) current: PathNode,
     /// Whether the cursor is completed, i.e. at the root node as a result of traversal (or when `complete`d).
     /// If `true`, the cursor cannot be moved.
-    is_completed: bool,
+    pub(super) is_completed: bool,
 }
 
 impl Iterator for Cursor {

crates/codegen/parser/runtime/src/kinds.rs

@@ -13,11 +13,17 @@ use napi_derive::napi;
     strum_macros::Display,
     strum_macros::EnumString,
 )]
+#[strum(use_phf)]
 #[cfg_attr( feature = "slang_napi_interfaces", /* derives `Clone` and `Copy` */ napi(string_enum, namespace = "kinds") )]
 #[cfg_attr(not(feature = "slang_napi_interfaces"), derive(Clone, Copy))]
 pub enum TokenKind {
     SKIPPED,
+    Identifier,
     // Expanded by the template engine
+    // Used for testing
+    X,
+    Y,
+    Z,
 }
 
 #[derive(
@@ -32,12 +38,18 @@ pub enum TokenKind {
     strum_macros::Display,
     strum_macros::EnumString,
 )]
+#[strum(use_phf)]
 #[cfg_attr( feature = "slang_napi_interfaces", /* derives `Clone` and `Copy` */ napi(string_enum, namespace = "kinds") )]
 #[cfg_attr(not(feature = "slang_napi_interfaces"), derive(Clone, Copy))]
 pub enum RuleKind {
     LeadingTrivia,
     TrailingTrivia,
     // Expanded by the template engine
+    // Used for testing
+    A,
+    B,
+    C,
+    D,
 }
 
 impl RuleKind {
@@ -58,6 +70,7 @@ impl RuleKind {
     strum_macros::Display,
     strum_macros::EnumString,
 )]
+#[strum(use_phf)]
 #[cfg_attr(feature = "slang_napi_interfaces", /* derives `Clone` and `Copy` */ napi(string_enum, namespace = "kinds"))]
 #[cfg_attr(not(feature = "slang_napi_interfaces"), derive(Clone, Copy))]
 pub enum FieldName {

crates/codegen/parser/runtime/src/lib.rs

@@ -9,7 +9,16 @@ pub mod kinds;
 pub(crate) mod lexer;
 pub mod parse_error;
 pub mod parse_output;
+pub mod query_engine;
+pub mod query_model;
+pub(crate) mod query_parser;
 pub mod text_index;
 
 #[cfg(feature = "slang_napi_interfaces")]
 pub mod napi;
+
+#[cfg(test)]
+pub mod query_engine_tests;
+
+#[cfg(test)]
+pub mod query_parser_tests;