Add full-lexer feature (#36)

parser/Cargo.toml

@@ -13,6 +13,7 @@ default = ["location"]
 location = ["rustpython-ast/location", "rustpython-parser-core/location"]
 serde = ["dep:serde", "rustpython-parser-core/serde"]
 all-nodes-with-ranges = ["rustpython-ast/all-nodes-with-ranges"]
+full-lexer = []
 
 [build-dependencies]
 anyhow = { workspace = true }

parser/src/lexer.rs

@@ -450,6 +450,7 @@ where
     }
 
     /// Lex a single comment.
+    #[cfg(feature = "full-lexer")]
     fn lex_comment(&mut self) -> LexResult {
         let start_pos = self.get_pos();
         let mut value = String::new();
@@ -465,6 +466,20 @@ where
         }
     }
 
+    /// Discard comment if full-lexer is not enabled.
+    #[cfg(not(feature = "full-lexer"))]
+    fn lex_comment(&mut self) {
+        loop {
+            match self.window[0] {
+                Some('\n' | '\r') | None => {
+                    return;
+                }
+                Some(_) => {}
+            }
+            self.next_char().unwrap();
+        }
+    }
+
     /// Lex a string literal.
     fn lex_string(&mut self, kind: StringKind) -> LexResult {
         let start_pos = self.get_pos();
@@ -611,8 +626,9 @@ where
                     tabs += 1;
                 }
                 Some('#') => {
-                    let comment = self.lex_comment()?;
-                    self.emit(comment);
+                    let _comment = self.lex_comment();
+                    #[cfg(feature = "full-lexer")]
+                    self.emit(_comment?);
                     spaces = 0;
                     tabs = 0;
                 }
@@ -753,8 +769,9 @@ where
                 self.emit(number);
             }
             '#' => {
-                let comment = self.lex_comment()?;
-                self.emit(comment);
+                let _comment = self.lex_comment();
+                #[cfg(feature = "full-lexer")]
+                self.emit(_comment?);
             }
             '"' | '\'' => {
                 let string = self.lex_string(StringKind::String)?;
@@ -1101,6 +1118,7 @@ where
                     self.at_begin_of_line = true;
                     self.emit((Tok::Newline, TextRange::new(tok_start, tok_end)));
                 } else {
+                    #[cfg(feature = "full-lexer")]
                     self.emit((Tok::NonLogicalNewline, TextRange::new(tok_start, tok_end)));
                 }
             }
@@ -1408,6 +1426,7 @@ mod tests {
         ($($name:ident: $eol:expr,)*) => {
             $(
             #[test]
+            #[cfg(feature = "full-lexer")]
             fn $name() {
                 let source = format!(r"99232  # {}", $eol);
                 let tokens = lex_source(&source);
@@ -1428,6 +1447,7 @@ mod tests {
         ($($name:ident: $eol:expr,)*) => {
             $(
             #[test]
+            #[cfg(feature = "full-lexer")]
             fn $name() {
                 let source = format!("123  # Foo{}456", $eol);
                 let tokens = lex_source(&source);
@@ -1607,6 +1627,7 @@ mod tests {
         ($($name:ident: $eol:expr,)*) => {
         $(
             #[test]
+            #[cfg(feature = "full-lexer")]
             fn $name() {
                 let source = r"x = [
 
@@ -1669,6 +1690,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg(feature = "full-lexer")]
     fn test_non_logical_newline_in_string_continuation() {
         let source = r"(
     'a'
@@ -1698,6 +1720,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg(feature = "full-lexer")]
     fn test_logical_newline_line_comment() {
         let source = "#Hello\n#World";
         let tokens = lex_source(source);

parser/src/parser.rs

@@ -190,9 +190,10 @@ pub fn parse_tokens(
     source_path: &str,
 ) -> Result<ast::Mod, ParseError> {
     let marker_token = (Tok::start_marker(mode), Default::default());
-    let lexer = iter::once(Ok(marker_token))
-        .chain(lxr)
-        .filter_ok(|(tok, _)| !matches!(tok, Tok::Comment { .. } | Tok::NonLogicalNewline));
+    let lexer = iter::once(Ok(marker_token)).chain(lxr);
+    #[cfg(feature = "full-lexer")]
+    let lexer =
+        lexer.filter_ok(|(tok, _)| !matches!(tok, Tok::Comment { .. } | Tok::NonLogicalNewline));
     python::TopParser::new()
         .parse(
             lexer

parser/src/python.lalrpop

@@ -1743,6 +1743,6 @@ extern {
         name => token::Tok::Name { name: <String> },
         "\n" => token::Tok::Newline,
         ";" => token::Tok::Semi,
-        "#" => token::Tok::Comment(_),
+        // "#" => token::Tok::Comment(_),
     }
 }

parser/src/soft_keywords.rs

@@ -86,18 +86,19 @@ where
 
         self.start_of_line = next.as_ref().map_or(false, |lex_result| {
             lex_result.as_ref().map_or(false, |(tok, _)| {
+                #[cfg(feature = "full-lexer")]
                 if matches!(tok, Tok::NonLogicalNewline | Tok::Comment { .. }) {
-                    self.start_of_line
-                } else {
-                    matches!(
-                        tok,
-                        Tok::StartModule
-                            | Tok::StartInteractive
-                            | Tok::Newline
-                            | Tok::Indent
-                            | Tok::Dedent
-                    )
+                    return self.start_of_line;
                 }
+
+                matches!(
+                    tok,
+                    Tok::StartModule
+                        | Tok::StartInteractive
+                        | Tok::Newline
+                        | Tok::Indent
+                        | Tok::Dedent
+                )
             })
         });
 

parser/src/token.rs

@@ -43,11 +43,13 @@ pub enum Tok {
         triple_quoted: bool,
     },
     /// Token value for a comment. These are filtered out of the token stream prior to parsing.
+    #[cfg(feature = "full-lexer")]
     Comment(String),
     /// Token value for a newline.
     Newline,
     /// Token value for a newline that is not a logical line break. These are filtered out of
     /// the token stream prior to parsing.
+    #[cfg(feature = "full-lexer")]
     NonLogicalNewline,
     /// Token value for an indent.
     Indent,
@@ -223,6 +225,7 @@ impl fmt::Display for Tok {
                 write!(f, "{kind}{quotes}{value}{quotes}")
             }
             Newline => f.write_str("Newline"),
+            #[cfg(feature = "full-lexer")]
             NonLogicalNewline => f.write_str("NonLogicalNewline"),
             Indent => f.write_str("Indent"),
             Dedent => f.write_str("Dedent"),
@@ -236,6 +239,7 @@ impl fmt::Display for Tok {
             Rsqb => f.write_str("']'"),
             Colon => f.write_str("':'"),
             Comma => f.write_str("','"),
+            #[cfg(feature = "full-lexer")]
             Comment(value) => f.write_str(value),
             Semi => f.write_str("';'"),
             Plus => f.write_str("'+'"),