Create stand-alone json parser (including scanner).

src/scanner.cc

 // Copyright 2011 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
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 324 matching lines @@
   // in object literals.
   Init();
   // Skip initial whitespace allowing HTML comment ends just like
   // after a newline and scan first token.
   has_line_terminator_before_next_ = true;
   SkipWhiteSpace();
   Scan();
 }
 
 
-// ----------------------------------------------------------------------------
-// JsonScanner
-
-JsonScanner::JsonScanner(UnicodeCache* unicode_cache)
-    : Scanner(unicode_cache) { }
-
-
-void JsonScanner::Initialize(UC16CharacterStream* source) {
-  source_ = source;
-  Init();
-  // Skip initial whitespace.
-  SkipJsonWhiteSpace();
-  // Preload first token as look-ahead.
-  ScanJson();
-}
-
-
-Token::Value JsonScanner::Next() {
-  // BUG 1215673: Find a thread safe way to set a stack limit in
-  // pre-parse mode. Otherwise, we cannot safely pre-parse from other
-  // threads.
-  current_ = next_;
-  // Check for stack-overflow before returning any tokens.
-  ScanJson();
-  return current_.token;
-}
-
-
-bool JsonScanner::SkipJsonWhiteSpace() {
-  int start_position = source_pos();
-  // JSON WhiteSpace is tab, carrige-return, newline and space.
-  while (c0_ == ' ' || c0_ == '\n' || c0_ == '\r' || c0_ == '\t') {
-    Advance();
-  }
-  return source_pos() != start_position;
-}
-
-
-void JsonScanner::ScanJson() {
-  next_.literal_chars = NULL;
-  Token::Value token;
-  do {
-    // Remember the position of the next token
-    next_.location.beg_pos = source_pos();
-    switch (c0_) {
-      case '\t':
-      case '\r':
-      case '\n':
-      case ' ':
-        Advance();
-        token = Token::WHITESPACE;
-        break;
-      case '{':
-        Advance();
-        token = Token::LBRACE;
-        break;
-      case '}':
-        Advance();
-        token = Token::RBRACE;
-        break;
-      case '[':
-        Advance();
-        token = Token::LBRACK;
-        break;
-      case ']':
-        Advance();
-        token = Token::RBRACK;
-        break;
-      case ':':
-        Advance();
-        token = Token::COLON;
-        break;
-      case ',':
-        Advance();
-        token = Token::COMMA;
-        break;
-      case '"':
-        token = ScanJsonString();
-        break;
-      case '-':
-      case '0':
-      case '1':
-      case '2':
-      case '3':
-      case '4':
-      case '5':
-      case '6':
-      case '7':
-      case '8':
-      case '9':
-        token = ScanJsonNumber();
-        break;
-      case 't':
-        token = ScanJsonIdentifier("true", Token::TRUE_LITERAL);
-        break;
-      case 'f':
-        token = ScanJsonIdentifier("false", Token::FALSE_LITERAL);
-        break;
-      case 'n':
-        token = ScanJsonIdentifier("null", Token::NULL_LITERAL);
-        break;
-      default:
-        if (c0_ < 0) {
-          Advance();
-          token = Token::EOS;
-        } else {
-          Advance();
-          token = Select(Token::ILLEGAL);
-        }
-    }
-  } while (token == Token::WHITESPACE);
-
-  next_.location.end_pos = source_pos();
-  next_.token = token;
-}
-
-
-Token::Value JsonScanner::ScanJsonString() {
-  ASSERT_EQ('"', c0_);
-  Advance();
-  LiteralScope literal(this);
-  while (c0_ != '"') {
-    // Check for control character (0x00-0x1f) or unterminated string (<0).
-    if (c0_ < 0x20) return Token::ILLEGAL;
-    if (c0_ != '\\') {
-      AddLiteralCharAdvance();
-    } else {
-      Advance();
-      switch (c0_) {
-        case '"':
-        case '\\':
-        case '/':
-          AddLiteralChar(c0_);
-          break;
-        case 'b':
-          AddLiteralChar('\x08');
-          break;
-        case 'f':
-          AddLiteralChar('\x0c');
-          break;
-        case 'n':
-          AddLiteralChar('\x0a');
-          break;
-        case 'r':
-          AddLiteralChar('\x0d');
-          break;
-        case 't':
-          AddLiteralChar('\x09');
-          break;
-        case 'u': {
-          uc32 value = 0;
-          for (int i = 0; i < 4; i++) {
-            Advance();
-            int digit = HexValue(c0_);
-            if (digit < 0) {
-              return Token::ILLEGAL;
-            }
-            value = value * 16 + digit;
-          }
-          AddLiteralChar(value);
-          break;
-        }
-        default:
-          return Token::ILLEGAL;
-      }
-      Advance();
-    }
-  }
-  literal.Complete();
-  Advance();
-  return Token::STRING;
-}
-
-
-Token::Value JsonScanner::ScanJsonNumber() {
-  LiteralScope literal(this);
-  bool negative = false;
-
-  if (c0_ == '-') {
-    AddLiteralCharAdvance();
-    negative = true;
-  }
-  if (c0_ == '0') {
-    AddLiteralCharAdvance();
-    // Prefix zero is only allowed if it's the only digit before
-    // a decimal point or exponent.
-    if ('0' <= c0_ && c0_ <= '9') return Token::ILLEGAL;
-  } else {
-    int i = 0;
-    int digits = 0;
-    if (c0_ < '1' || c0_ > '9') return Token::ILLEGAL;
-    do {
-      i = i * 10 + c0_ - '0';
-      digits++;
-      AddLiteralCharAdvance();
-    } while (c0_ >= '0' && c0_ <= '9');
-    if (c0_ != '.' && c0_ != 'e' && c0_ != 'E' && digits < 10) {
-      number_ = (negative ? -i : i);
-      return Token::NUMBER;
-    }
-  }
-  if (c0_ == '.') {
-    AddLiteralCharAdvance();
-    if (c0_ < '0' || c0_ > '9') return Token::ILLEGAL;
-    do {
-      AddLiteralCharAdvance();
-    } while (c0_ >= '0' && c0_ <= '9');
-  }
-  if (AsciiAlphaToLower(c0_) == 'e') {
-    AddLiteralCharAdvance();
-    if (c0_ == '-' || c0_ == '+') AddLiteralCharAdvance();
-    if (c0_ < '0' || c0_ > '9') return Token::ILLEGAL;
-    do {
-      AddLiteralCharAdvance();
-    } while (c0_ >= '0' && c0_ <= '9');
-  }
-  literal.Complete();
-  ASSERT_NOT_NULL(next_.literal_chars);
-  number_ = StringToDouble(unicode_cache_,
-                           next_.literal_chars->ascii_literal(),
-                           NO_FLAGS,  // Hex, octal or trailing junk.
-                           OS::nan_value());
-  return Token::NUMBER;
-}
-
-
-Token::Value JsonScanner::ScanJsonIdentifier(const char* text,
-                                             Token::Value token) {
-  LiteralScope literal(this);
-  while (*text != '\0') {
-    if (c0_ != *text) return Token::ILLEGAL;
-    Advance();
-    text++;
-  }
-  if (unicode_cache_->IsIdentifierPart(c0_)) return Token::ILLEGAL;
-  literal.Complete();
-  return token;
-}
-
-
 } }  // namespace v8::internal