text: // Copyright 2006-2008 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
  //       with the distribution.
  //     * Neither the name of Google Inc. nor the names of its
  //       contributors may be used to endorse or promote products derived
  //       from this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #ifndef V8_TOKEN_H_
  #define V8_TOKEN_H_
  
  namespace v8 { namespace internal {
  
  // TOKEN_LIST takes a list of 3 macros M, all of which satisfy the
  // same signature M(name, string, precedence), where name is the
  // symbolic token name, string is the corresponding syntactic symbol
  // (or NULL, for literals), and precedence is the precedence (or 0).
  // The parameters are invoked for token categories as follows:
  //
  //   T: Non-keyword tokens
  //   K: Keyword tokens
  //   F: Future (reserved) keyword tokens
  
  // IGNORE_TOKEN is a convenience macro that can be supplied as
  // an argument (at any position) for a TOKEN_LIST call. It does
  // nothing with tokens belonging to the respective category.
  
  #define IGNORE_TOKEN(name, string, precedence)
  
  #define TOKEN_LIST(T, K, F)                                             \
    /* End of source indicator. */                                        \
    T(EOS, "EOS", 0)                                                      \
                                                                          \
    /* Punctuators (ECMA-262, section 7.7, page 15). */                   \
    T(LPAREN, "(", 0)                                                     \
    T(RPAREN, ")", 0)                                                     \
    T(LBRACK, "[", 0)                                                     \
    T(RBRACK, "]", 0)                                                     \
    T(LBRACE, "{", 0)                                                     \
    T(RBRACE, "}", 0)                                                     \
    T(COLON, ":", 0)                                                      \
    T(SEMICOLON, ";", 0)                                                  \
    T(PERIOD, ".", 0)                                                     \
    T(CONDITIONAL, "?", 3)                                                \
    T(INC, "++", 0)                                                       \
    T(DEC, "--", 0)                                                       \
                                                                          \
    /* Assignment operators. */                                           \
    /* IsAssignmentOp() relies on this block of enum values */            \
    /* being contiguous and sorted in the same order! */                  \
    T(INIT_VAR, "=init_var", 2)  /* AST-use only. */                      \
    T(INIT_CONST, "=init_const", 2)  /* AST-use only. */                  \
    T(ASSIGN, "=", 2)                                                     \
    T(ASSIGN_BIT_OR, "|=", 2)                                             \
    T(ASSIGN_BIT_XOR, "^=", 2)                                            \
    T(ASSIGN_BIT_AND, "&=", 2)                                            \
    T(ASSIGN_SHL, "<<=", 2)                                               \
    T(ASSIGN_SAR, ">>=", 2)                                               \
    T(ASSIGN_SHR, ">>>=", 2)                                              \
    T(ASSIGN_ADD, "+=", 2)                                                \
    T(ASSIGN_SUB, "-=", 2)                                                \
    T(ASSIGN_MUL, "*=", 2)                                                \
    T(ASSIGN_DIV, "/=", 2)                                                \
    T(ASSIGN_MOD, "%=", 2)                                                \
                                                                          \
    /* Binary operators sorted by precedence. */                          \
    /* IsBinaryOp() relies on this block of enum values */                \
    /* being contiguous and sorted in the same order! */                  \
    T(COMMA, ",", 1)                                                      \
    T(OR, "||", 4)                                                        \
    T(AND, "&&", 5)                                                       \
    T(BIT_OR, "|", 6)                                                     \
    T(BIT_XOR, "^", 7)                                                    \
    T(BIT_AND, "&", 8)                                                    \
    T(SHL, "<<", 11)                                                      \
    T(SAR, ">>", 11)                                                      \
    T(SHR, ">>>", 11)                                                     \
    T(ADD, "+", 12)                                                       \
    T(SUB, "-", 12)                                                       \
    T(MUL, "*", 13)                                                       \
    T(DIV, "/", 13)                                                       \
    T(MOD, "%", 13)                                                       \
                                                                          \
    /* Compare operators sorted by precedence. */                         \
    /* IsCompareOp() relies on this block of enum values */               \
    /* being contiguous and sorted in the same order! */                  \
    T(EQ, "==", 9)                                                        \
    T(NE, "!=", 9)                                                        \
    T(EQ_STRICT, "===", 9)                                                \
    T(NE_STRICT, "!==", 9)                                                \
    T(LT, "<", 10)                                                        \
    T(GT, ">", 10)                                                        \
    T(LTE, "<=", 10)                                                      \
    T(GTE, ">=", 10)                                                      \
    K(INSTANCEOF, "instanceof", 10)                                       \
    K(IN, "in", 10)                                                       \
                                                                          \
    /* Unary operators. */                                                \
    /* IsUnaryOp() relies on this block of enum values */                 \
    /* being contiguous and sorted in the same order! */                  \
    T(NOT, "!", 0)                                                        \
    T(BIT_NOT, "~", 0)                                                    \
    K(DELETE, "delete", 0)                                                \
    K(TYPEOF, "typeof", 0)                                                \
    K(VOID, "void", 0)                                                    \
                                                                          \
    /* Keywords (ECMA-262, section 7.5.2, page 13). */                    \
    K(BREAK, "break", 0)                                                  \
    K(CASE, "case", 0)                                                    \
    K(CATCH, "catch", 0)                                                  \
    K(CONTINUE, "continue", 0)                                            \
    K(DEBUGGER, "debugger", 0)                                            \
    K(DEFAULT, "default", 0)                                              \
    /* DELETE */                                                          \
    K(DO, "do", 0)                                                        \
    K(ELSE, "else", 0)                                                    \
    K(FINALLY, "finally", 0)                                              \
    K(FOR, "for", 0)                                                      \
    K(FUNCTION, "function", 0)                                            \
    K(IF, "if", 0)                                                        \
    /* IN */                                                              \
    /* INSTANCEOF */                                                      \
    K(NEW, "new", 0)                                                      \
    K(RETURN, "return", 0)                                                \
    K(SWITCH, "switch", 0)                                                \
    K(THIS, "this", 0)                                                    \
    K(THROW, "throw", 0)                                                  \
    K(TRY, "try", 0)                                                      \
    /* TYPEOF */                                                          \
    K(VAR, "var", 0)                                                      \
    /* VOID */                                                            \
    K(WHILE, "while", 0)                                                  \
    K(WITH, "with", 0)                                                    \
                                                                          \
    /* Future reserved words (ECMA-262, section 7.5.3, page 14). */       \
    F(ABSTRACT, "abstract", 0)                                            \
    F(BOOLEAN, "boolean", 0)                                              \
    F(BYTE, "byte", 0)                                                    \
    F(CHAR, "char", 0)                                                    \
    F(CLASS, "class", 0)                                                  \
    K(CONST, "const", 0)                                                  \
    F(DOUBLE, "double", 0)                                                \
    F(ENUM, "enum", 0)                                                    \
    F(EXPORT, "export", 0)                                                \
    F(EXTENDS, "extends", 0)                                              \
    F(FINAL, "final", 0)                                                  \
    F(FLOAT, "float", 0)                                                  \
    F(GOTO, "goto", 0)                                                    \
    F(IMPLEMENTS, "implements", 0)                                        \
    F(IMPORT, "import", 0)                                                \
    F(INT, "int", 0)                                                      \
    F(INTERFACE, "interface", 0)                                          \
    F(LONG, "long", 0)                                                    \
    K(NATIVE, "native", 0)                                                \
    F(PACKAGE, "package", 0)                                              \
    F(PRIVATE, "private", 0)                                              \
    F(PROTECTED, "protected", 0)                                          \
    F(PUBLIC, "public", 0)                                                \
    F(SHORT, "short", 0)                                                  \
    F(STATIC, "static", 0)                                                \
    F(SUPER, "super", 0)                                                  \
    F(SYNCHRONIZED, "synchronized", 0)                                    \
    F(THROWS, "throws", 0)                                                \
    F(TRANSIENT, "transient", 0)                                          \
    F(VOLATILE, "volatile", 0)                                            \
                                                                          \
    /* Literals (ECMA-262, section 7.8, page 16). */                      \
    K(NULL_LITERAL, "null", 0)                                            \
    K(TRUE_LITERAL, "true", 0)                                            \
    K(FALSE_LITERAL, "false", 0)                                          \
    T(NUMBER, NULL, 0)                                                    \
    T(STRING, NULL, 0)                                                    \
                                                                          \
    /* Identifiers (not keywords or future reserved words). */            \
    T(IDENTIFIER, NULL, 0)                                                \
                                                                          \
    /* Illegal token - not able to scan. */                               \
    T(ILLEGAL, "ILLEGAL", 0)                                              \
                                                                          \
    /* Scanner-internal use only. */                                      \
    T(COMMENT, NULL, 0)
  
  
  class Token {
   public:
    // All token values.
  #define T(name, string, precedence) name,
    enum Value {
      TOKEN_LIST(T, T, IGNORE_TOKEN)
      NUM_TOKENS
    };
  #undef T
  
  #ifdef DEBUG
    // Returns a string corresponding to the C++ token name
    // (e.g. "LT" for the token LT).
    static const char* Name(Value tok) {
      ASSERT(0 <= tok && tok < NUM_TOKENS);
      return name_[tok];
    }
  #endif
  
    // Predicates
    static bool IsAssignmentOp(Value tok) {
      return INIT_VAR <= tok && tok <= ASSIGN_MOD;
    }
  
    static bool IsBinaryOp(Value op) {
      return COMMA <= op && op <= MOD;
    }
  
    static bool IsCompareOp(Value op) {
      return EQ <= op && op <= IN;
    }
  
    static bool IsBitOp(Value op) {
      return (BIT_OR <= op && op <= SHR) || op == BIT_NOT;
    }
  
    static bool IsUnaryOp(Value op) {
      return (NOT <= op && op <= VOID) || op == ADD || op == SUB;
    }
  
    static bool IsCountOp(Value op) {
      return op == INC || op == DEC;
    }
  
    // Returns a string corresponding to the JS token string
    // (.e., "<" for the token LT) or NULL if the token doesn't
    // have a (unique) string (e.g. an IDENTIFIER).
    static const char* String(Value tok) {
      ASSERT(0 <= tok && tok < NUM_TOKENS);
      return string_[tok];
    }
  
    // Returns the precedence > 0 for binary and compare
    // operators; returns 0 otherwise.
    static int Precedence(Value tok) {
      ASSERT(0 <= tok && tok < NUM_TOKENS);
      return precedence_[tok];
    }
  
    // Returns the keyword value if str is a keyword;
    // returns IDENTIFIER otherwise. The class must
    // have been initialized.
    static Value Lookup(const char* str);
  
    // Must be called once to initialize the class.
    // Multiple calls are ignored.
    static void Initialize();
  
   private:
  #ifdef DEBUG
    static const char* name_[NUM_TOKENS];
  #endif
    static const char* string_[NUM_TOKENS];
    static int8_t precedence_[NUM_TOKENS];
  };
  
  } }  // namespace v8::internal
  
  #endif  // V8_TOKEN_H_
  