Move part of scanner.* into scanner-base.* for reuse in preparser scanner.

src/scanner.cc

Index: src/scanner.cc
diff --git a/src/scanner.cc b/src/scanner.cc
index 79d63f1774dceaceceec1eccb19aebb218bb3a34..a24952ac24731f13450f0b473ae59324ffc9b6a0 100755
--- a/src/scanner.cc
+++ b/src/scanner.cc
@@ -184,142 +184,6 @@ void ExternalStringUTF16Buffer<StringType, CharType>::SeekForward(int pos) {
   pos_ = pos;
 }
 
-
-// ----------------------------------------------------------------------------
-// Keyword Matcher
-
-KeywordMatcher::FirstState KeywordMatcher::first_states_[] = {
-  { "break",  KEYWORD_PREFIX, Token::BREAK },
-  { NULL,     C,              Token::ILLEGAL },
-  { NULL,     D,              Token::ILLEGAL },
-  { "else",   KEYWORD_PREFIX, Token::ELSE },
-  { NULL,     F,              Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { NULL,     I,              Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { NULL,     N,              Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { "return", KEYWORD_PREFIX, Token::RETURN },
-  { "switch", KEYWORD_PREFIX, Token::SWITCH },
-  { NULL,     T,              Token::ILLEGAL },
-  { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { NULL,     V,              Token::ILLEGAL },
-  { NULL,     W,              Token::ILLEGAL }
-};
-
-
-void KeywordMatcher::Step(uc32 input) {
-  switch (state_) {
-    case INITIAL: {
-      // matching the first character is the only state with significant fanout.
-      // Match only lower-case letters in range 'b'..'w'.
-      unsigned int offset = input - kFirstCharRangeMin;
-      if (offset < kFirstCharRangeLength) {
-        state_ = first_states_[offset].state;
-        if (state_ == KEYWORD_PREFIX) {
-          keyword_ = first_states_[offset].keyword;
-          counter_ = 1;
-          keyword_token_ = first_states_[offset].token;
-        }
-        return;
-      }
-      break;
-    }
-    case KEYWORD_PREFIX:
-      if (keyword_[counter_] == input) {
-        ASSERT_NE(input, '\0');
-        counter_++;
-        if (keyword_[counter_] == '\0') {
-          state_ = KEYWORD_MATCHED;
-          token_ = keyword_token_;
-        }
-        return;
-      }
-      break;
-    case KEYWORD_MATCHED:
-      token_ = Token::IDENTIFIER;
-      break;
-    case C:
-      if (MatchState(input, 'a', CA)) return;
-      if (MatchState(input, 'o', CO)) return;
-      break;
-    case CA:
-      if (MatchKeywordStart(input, "case", 2, Token::CASE)) return;
-      if (MatchKeywordStart(input, "catch", 2, Token::CATCH)) return;
-      break;
-    case CO:
-      if (MatchState(input, 'n', CON)) return;
-      break;
-    case CON:
-      if (MatchKeywordStart(input, "const", 3, Token::CONST)) return;
-      if (MatchKeywordStart(input, "continue", 3, Token::CONTINUE)) return;
-      break;
-    case D:
-      if (MatchState(input, 'e', DE)) return;
-      if (MatchKeyword(input, 'o', KEYWORD_MATCHED, Token::DO)) return;
-      break;
-    case DE:
-      if (MatchKeywordStart(input, "debugger", 2, Token::DEBUGGER)) return;
-      if (MatchKeywordStart(input, "default", 2, Token::DEFAULT)) return;
-      if (MatchKeywordStart(input, "delete", 2, Token::DELETE)) return;
-      break;
-    case F:
-      if (MatchKeywordStart(input, "false", 1, Token::FALSE_LITERAL)) return;
-      if (MatchKeywordStart(input, "finally", 1, Token::FINALLY)) return;
-      if (MatchKeywordStart(input, "for", 1, Token::FOR)) return;
-      if (MatchKeywordStart(input, "function", 1, Token::FUNCTION)) return;
-      break;
-    case I:
-      if (MatchKeyword(input, 'f', KEYWORD_MATCHED, Token::IF)) return;
-      if (MatchKeyword(input, 'n', IN, Token::IN)) return;
-      break;
-    case IN:
-      token_ = Token::IDENTIFIER;
-      if (MatchKeywordStart(input, "instanceof", 2, Token::INSTANCEOF)) {
-        return;
-      }
-      break;
-    case N:
-      if (MatchKeywordStart(input, "native", 1, Token::NATIVE)) return;
-      if (MatchKeywordStart(input, "new", 1, Token::NEW)) return;
-      if (MatchKeywordStart(input, "null", 1, Token::NULL_LITERAL)) return;
-      break;
-    case T:
-      if (MatchState(input, 'h', TH)) return;
-      if (MatchState(input, 'r', TR)) return;
-      if (MatchKeywordStart(input, "typeof", 1, Token::TYPEOF)) return;
-      break;
-    case TH:
-      if (MatchKeywordStart(input, "this", 2, Token::THIS)) return;
-      if (MatchKeywordStart(input, "throw", 2, Token::THROW)) return;
-      break;
-    case TR:
-      if (MatchKeywordStart(input, "true", 2, Token::TRUE_LITERAL)) return;
-      if (MatchKeyword(input, 'y', KEYWORD_MATCHED, Token::TRY)) return;
-      break;
-    case V:
-      if (MatchKeywordStart(input, "var", 1, Token::VAR)) return;
-      if (MatchKeywordStart(input, "void", 1, Token::VOID)) return;
-      break;
-    case W:
-      if (MatchKeywordStart(input, "while", 1, Token::WHILE)) return;
-      if (MatchKeywordStart(input, "with", 1, Token::WITH)) return;
-      break;
-    default:
-      UNREACHABLE();
-  }
-  // On fallthrough, it's a failure.
-  state_ = UNMATCHABLE;
-}
-
-
-
 // ----------------------------------------------------------------------------
 // Scanner::LiteralScope