Experimental parser: unify regex handling with the baseline.

src/lexer/lexer.re

 // Portions of this code based on re2c:
 //   (re2c/examples/push.re)
 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 177 matching lines @@
     re2c:define:YYCONDTYPE = Condition;
     re2c:define:YYCURSOR = cursor_;
     re2c:define:YYCTYPE = uint8_t;
     re2c:define:YYLIMIT = limit_;
     re2c:define:YYMARKER = marker_;
 
     eof = "\000";
     any = [\000-\377];
     whitespace_char = [ \t\v\f\r];
     whitespace = whitespace_char+;
-    identifier_start_ = [$_\\a-zA-Z];
-    identifier_char = [$_\\a-zA-Z0-9];
+    identifier_start_ = [$_a-zA-Z];
+    identifier_char = [$_a-zA-Z0-9];
     not_identifier_char = any\identifier_char;
+    illegal_after_identifier = [\\];
     line_terminator = [\n\r]+;
     digit = [0-9];
     hex_digit = [0-9a-fA-F];
     maybe_exponent = ('e' [-+]? digit+)?;
 
     <Normal> "break" not_identifier_char      { PUSH_TOKEN_LOOKAHEAD(Token::BREAK); }
     <Normal> "case" not_identifier_char       { PUSH_TOKEN_LOOKAHEAD(Token::CASE); }
     <Normal> "catch" not_identifier_char      { PUSH_TOKEN_LOOKAHEAD(Token::CATCH); }
     <Normal> "class" not_identifier_char      { PUSH_TOKEN_LOOKAHEAD(Token::FUTURE_RESERVED_WORD); }
     <Normal> "const" not_identifier_char      { PUSH_TOKEN_LOOKAHEAD(Token::CONST); }
@@ skipping 101 matching lines @@
 
     <Normal> line_terminator  { PUSH_LINE_TERMINATOR(); }
     <Normal> whitespace       { SKIP(); }
 
     <Normal> ["]           :=> DoubleQuoteString
     <Normal> [']           :=> SingleQuoteString
 
     <Normal> identifier_start_    :=> Identifier
 
     <Normal> eof           { PUSH_EOF_AND_RETURN();}
-    <Normal> any           { TERMINATE_ILLEGAL(); }
+    <Normal> any           { PUSH_TOKEN(Token::ILLEGAL); }
 
     <DoubleQuoteString> "\\\""  { goto yy0; }
     <DoubleQuoteString> '"'     { PUSH_TOKEN(Token::STRING);}
     <DoubleQuoteString> "\\" "\n" "\r"? { goto yy0; }
     <DoubleQuoteString> "\\" "\r" "\n"? { goto yy0; }
     <DoubleQuoteString> line_terminator { TERMINATE_ILLEGAL(); }
     <DoubleQuoteString> eof     { TERMINATE_ILLEGAL(); }
     <DoubleQuoteString> any     { goto yy0; }
 
     <SingleQuoteString> "\\'"   { goto yy0; }
     <SingleQuoteString> "'"     { PUSH_TOKEN(Token::STRING);}
     <SingleQuoteString> "\\" "\n" "\r"? { goto yy0; }
     <SingleQuoteString> "\\" "\r" "\n"? { goto yy0; }
     <SingleQuoteString> line_terminator { TERMINATE_ILLEGAL(); }
     <SingleQuoteString> eof     { TERMINATE_ILLEGAL(); }
     <SingleQuoteString> any     { goto yy0; }
 
     <Identifier> identifier_char+  { goto yy0; }
+    <Identifier> illegal_after_identifier { PUSH_TOKEN(Token::ILLEGAL); }
     <Identifier> any               { PUSH_TOKEN_LOOKAHEAD(Token::IDENTIFIER); }
 
     <SingleLineComment> line_terminator { PUSH_LINE_TERMINATOR();}
     <SingleLineComment> eof             { PUSH_LINE_TERMINATOR();}
     <SingleLineComment> any             { goto yy0; }
 
     <MultiLineComment> [*][//]  { PUSH_LINE_TERMINATOR();}
     <MultiLineComment> eof      { TERMINATE_ILLEGAL(); }
     <MultiLineComment> any      { goto yy0; }
 
@@ skipping 28 matching lines @@
     size_t start_offset = start_ - buffer_;
     memmove(buffer_, start_, limit_ - start_);
     marker_ -= start_offset;
     cursor_ -= start_offset;
     limit_ -= start_offset;
     start_ -= start_offset;
     real_start_ += start_offset;
   }
   return 0;
 }