refactor(es/parser): Detach swc_ecma_parser from swc_ecma_lexer

.changeset/funny-dragons-promise.md

@@ -0,0 +1,7 @@
+---
+swc_common: patch
+swc_ecma_lexer: major
+swc_ecma_parser: major
+---
+
+refactor(es/parser): detach `swc_ecma_parser` from `swc_emca_lexer`

bindings/binding_es_ast_viewer/src/lib.rs

@@ -6,10 +6,7 @@ use swc_core::{
     common::{errors::ColorConfig, FileName, Globals, Mark, SourceMap, GLOBALS},
     ecma::{
         ast::*,
-        parser::{
-            unstable::{Buffer, Capturing, ParserTrait},
-            EsSyntax, Lexer, Parser, StringInput, Syntax, TsSyntax,
-        },
+        parser::{unstable::Capturing, EsSyntax, Lexer, Parser, StringInput, Syntax, TsSyntax},
         transforms::base::resolver,
         visit::VisitMutWith,
     },

crates/swc_common/src/input.rs

@@ -44,6 +44,35 @@ impl<'a> StringInput<'a> {
         self.iter.as_str()
     }
 
+    #[inline(always)]
+    /// Compared to [StringInput::slice], this function doesn't set
+    /// `self.last_pos = end` because in most cases this property has been
+    /// satisfied but the compiler cannot optimize it.
+    ///
+    /// Caution: This function should only be used internally and will be
+    /// changed in the future.
+    ///
+    /// # Safety
+    /// - start should be less than or equal to end.
+    /// - start and end should be in the valid range of input.
+    pub unsafe fn slice_to_cur(&mut self, start: BytePos) -> &'a str {
+        let end = self.last_pos;
+
+        debug_assert!(start <= end, "Cannot slice {start:?}..{end:?}");
+        let s = self.orig;
+
+        let start_idx = (start - self.orig_start).0 as usize;
+        let end_idx = (end - self.orig_start).0 as usize;
+
+        debug_assert!(end_idx <= s.len());
+
+        let ret = unsafe { s.get_unchecked(start_idx..end_idx) };
+
+        self.iter = unsafe { s.get_unchecked(end_idx..) }.chars();
+
+        ret
+    }
+
     #[inline]
     pub fn bump_bytes(&mut self, n: usize) {
         unsafe {

crates/swc_ecma_lexer/Cargo.toml

@@ -31,35 +31,29 @@ verify        = ["swc_ecma_visit"]
 bitflags    = { workspace = true }
 either      = { workspace = true }
 num-bigint  = { workspace = true }
-phf         = { workspace = true, features = ["macros"] }
 rustc-hash  = { workspace = true }
 seq-macro   = { workspace = true }
 serde       = { workspace = true, features = ["derive"] }
 smallvec    = { workspace = true }
 smartstring = { workspace = true }
 tracing     = { workspace = true }
 
-swc_atoms      = { version = "7.0.0", path = "../swc_atoms" }
-swc_common     = { version = "15.0.0", path = "../swc_common" }
-swc_ecma_ast   = { version = "16.0.0", path = "../swc_ecma_ast" }
-swc_ecma_visit = { version = "16.0.0", path = "../swc_ecma_visit", optional = true }
+swc_atoms       = { version = "7.0.0", path = "../swc_atoms" }
+swc_common      = { version = "15.0.0", path = "../swc_common" }
+swc_ecma_ast    = { version = "16.0.0", path = "../swc_ecma_ast" }
+swc_ecma_parser = { version = "25.0.0", path = "../swc_ecma_parser" }
+swc_ecma_visit  = { version = "16.0.0", path = "../swc_ecma_visit", optional = true }
 
 [target.'cfg(not(any(target_arch = "wasm32", target_arch = "arm")))'.dependencies]
 stacker = { version = "0.1.15", optional = true }
 
 [dev-dependencies]
 
-codspeed-criterion-compat = { workspace = true }
 swc_ecma_ast = { version = "16.0.0", path = "../swc_ecma_ast", features = [
   "serde-impl",
 ] }
 swc_ecma_visit = { version = "16.0.0", path = "../swc_ecma_visit" }
-swc_malloc = { version = "1.2.4", path = "../swc_malloc" }
 testing = { version = "16.0.0", path = "../testing" }
 
 [[example]]
 name = "lexer"
-
-[[bench]]
-harness = false
-name    = "lexer"

crates/swc_ecma_lexer/README.md

@@ -0,0 +1,5 @@
+# swc_ecma_lexer
+
+This crate is no longer maintained and kept just for compatibility. Please use [swc_ecma_parser](https://github.com/swc-project/swc/tree/main/crates/swc_ecma_parser) instead, which provides higher performance.
+
+See more details in https://github.com/swc-project/swc/pull/11148.

crates/swc_ecma_lexer/src/common/lexer/mod.rs

@@ -99,7 +99,7 @@ impl From<UnicodeEscape> for CodePoint {
     }
 }
 
-pub type LexResult<T> = Result<T, crate::error::Error>;
+pub type LexResult<T> = swc_ecma_parser::lexer::LexResult<T>;
 
 fn remove_underscore(s: &str, has_underscore: bool) -> Cow<'_, str> {
     if has_underscore {