Experimental parser: kill unnecessary rules.

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 306 matching lines @@
     <Normal> "<<="         { PUSH_TOKEN(Token::ASSIGN_SHL); }
     <Normal> ">>="         { PUSH_TOKEN(Token::ASSIGN_SAR); }
     <Normal> "<="          { PUSH_TOKEN(Token::LTE); }
     <Normal> ">="          { PUSH_TOKEN(Token::GTE); }
     <Normal> "<<"          { PUSH_TOKEN(Token::SHL); }
     <Normal> ">>"          { PUSH_TOKEN(Token::SAR); }
     <Normal> "<"           { PUSH_TOKEN(Token::LT); }
     <Normal> ">"           { PUSH_TOKEN(Token::GT); }
 
     <Normal> number not_identifier_char { PUSH_TOKEN_LOOKAHEAD(Token::NUMBER); }
-    <Normal> number "\\u" [0-9a-fA-F]{4} { cursor_ -= 6; send(Token::ILLEGAL); start_ = cursor_; cursor_ += 6; if (ValidIdentifierStart()) { YYSETCONDITION(kConditionIdentifier); goto yyc_Identifier; } else { PUSH_TOKEN(Token::ILLEGAL); } }
     <Normal> number any   { PUSH_TOKEN_LOOKAHEAD(Token::ILLEGAL); }
 
     <Normal> "("           { PUSH_TOKEN(Token::LPAREN); }
     <Normal> ")"           { PUSH_TOKEN(Token::RPAREN); }
     <Normal> "["           { PUSH_TOKEN(Token::LBRACK); }
     <Normal> "]"           { PUSH_TOKEN(Token::RBRACK); }
     <Normal> "{"           { PUSH_TOKEN(Token::LBRACE); }
     <Normal> "}"           { PUSH_TOKEN(Token::RBRACE); }
     <Normal> ":"           { PUSH_TOKEN(Token::COLON); }
     <Normal> ";"           { PUSH_TOKEN(Token::SEMICOLON); }
@@ skipping 47 matching lines @@
     <SingleQuoteString> "\n"    => Normal { PUSH_TOKEN_LOOKAHEAD(Token::ILLEGAL); }
     <SingleQuoteString> "\r"    => Normal { PUSH_TOKEN_LOOKAHEAD(Token::ILLEGAL); }
     <SingleQuoteString> eof     { TERMINATE_ILLEGAL(); }
     <SingleQuoteString> any     { goto yyc_SingleQuoteString; }
 
     <Identifier> identifier_char+  { goto yyc_Identifier; }
     <Identifier> "\\u" [0-9a-fA-F]{4} { if (ValidIdentifierPart()) { goto yyc_Identifier; } YYSETCONDITION(kConditionNormal); send(Token::ILLEGAL); start_ = cursor_; goto yyc_Normal; }
     <Identifier> "\\"              { PUSH_TOKEN(Token::ILLEGAL); }
     <Identifier> any               { PUSH_TOKEN_LOOKAHEAD(Token::IDENTIFIER); }
 
-    <IdentifierIllegal> identifier_start  { PUSH_TOKEN_LOOKAHEAD(Token::ILLEGAL); }
-    <IdentifierIllegal> identifier_char\identifier_start  { marker_ = cursor_; goto yyc_IdentifierIllegal; }
-    <IdentifierIllegal> "\\u" [0-9a-fA-F]{4} { if (ValidIdentifierStart()) { cursor_ -= 6; PUSH_TOKEN(Token::ILLEGAL); } marker_ = cursor_; PUSH_TOKEN(Token::ILLEGAL); }
-    <IdentifierIllegal> "\\"+             { marker_ = cursor_; goto yyc_IdentifierIllegal; }
-    <IdentifierIllegal> any               { PUSH_TOKEN_LOOKAHEAD(Token::ILLEGAL); }
-
     <SingleLineComment> line_terminator { PUSH_LINE_TERMINATOR();}
     <SingleLineComment> eof             { start_ = cursor_ - 1; PUSH_TOKEN(Token::EOS); }
     <SingleLineComment> any             { goto yyc_SingleLineComment; }
 
     <MultiLineComment> [*][//]  { PUSH_LINE_TERMINATOR();}
     <MultiLineComment> eof      { start_ = cursor_ - 1; PUSH_TOKEN(Token::EOS); }
     <MultiLineComment> any      { goto yyc_MultiLineComment; }
 
     <HtmlComment> eof        { start_ = cursor_ - 1; PUSH_TOKEN(Token::EOS); }
     <HtmlComment> "-->"      { PUSH_LINE_TERMINATOR();}
@@ skipping 27 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;
 }