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/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.javascript;
/**
* This class implements the JavaScript scanner.
*
* It is based on the C source files jsscan.c and jsscan.h in the jsref package.
*
* @see org.mozilla.javascript.Parser
* @author Mike McCabe
* @author Brendan Eich
*/
public class Token {
public static enum CommentType {
LINE,
BLOCK_COMMENT,
JSDOC,
HTML
}
// debug flags
public static final boolean printTrees = false;
static final boolean printICode = false;
static final boolean printNames = printTrees || printICode;
/** Token types. These values correspond to JSTokenType values in jsscan.c. */
public static final int
// start enum
ERROR = -1, // well-known as the only code < EOF
EOF = 0, // end of file token - (not EOF_CHAR)
EOL = 1, // end of line
// Interpreter reuses the following as bytecodes
FIRST_BYTECODE_TOKEN = 2,
ENTERWITH = 2,
LEAVEWITH = 3,
RETURN = 4,
GOTO = 5,
IFEQ = 6,
IFNE = 7,
SETNAME = 8,
BITOR = 9,
BITXOR = 10,
BITAND = 11,
EQ = 12,
NE = 13,
LT = 14,
LE = 15,
GT = 16,
GE = 17,
LSH = 18,
RSH = 19,
URSH = 20,
ADD = 21,
SUB = 22,
MUL = 23,
DIV = 24,
MOD = 25,
NOT = 26,
BITNOT = 27,
POS = 28,
NEG = 29,
NEW = 30,
DELPROP = 31,
TYPEOF = 32,
GETPROP = 33,
GETPROPNOWARN = 34,
SETPROP = 35,
GETELEM = 36,
SETELEM = 37,
CALL = 38,
NAME = 39,
NUMBER = 40,
STRING = 41,
NULL = 42,
THIS = 43,
FALSE = 44,
TRUE = 45,
SHEQ = 46, // shallow equality (===)
SHNE = 47, // shallow inequality (!==)
REGEXP = 48,
BINDNAME = 49,
THROW = 50,
RETHROW = 51, // rethrow caught exception: catch (e if ) use it
IN = 52,
INSTANCEOF = 53,
LOCAL_LOAD = 54,
GETVAR = 55,
SETVAR = 56,
CATCH_SCOPE = 57,
ENUM_INIT_KEYS = 58,
ENUM_INIT_VALUES = 59,
ENUM_INIT_ARRAY = 60,
ENUM_INIT_VALUES_IN_ORDER = 61,
ENUM_NEXT = 62,
ENUM_ID = 63,
THISFN = 64,
RETURN_RESULT = 65, // to return previously stored return result
ARRAYLIT = 66, // array literal
OBJECTLIT = 67, // object literal
GET_REF = 68, // *reference
SET_REF = 69, // *reference = something
DEL_REF = 70, // delete reference
REF_CALL = 71, // f(args) = something or f(args)++
REF_SPECIAL = 72, // reference for special properties like __proto
YIELD = 73, // JS 1.7 yield pseudo keyword
STRICT_SETNAME = 74,
EXP = 75, // Exponentiation Operator
// For XML support:
DEFAULTNAMESPACE = 76, // default xml namespace =
ESCXMLATTR = 77,
ESCXMLTEXT = 78,
REF_MEMBER = 79, // Reference for x.@y, x..y etc.
REF_NS_MEMBER = 80, // Reference for x.ns::y, x..ns::y etc.
REF_NAME = 81, // Reference for @y, @[y] etc.
REF_NS_NAME = 82, // Reference for ns::y, @ns::y@[y] etc.
BIGINT = 83; // ES2020 BigInt
// End of interpreter bytecodes
public static final int LAST_BYTECODE_TOKEN = BIGINT,
TRY = 84,
SEMI = 85, // semicolon
LB = 86, // left and right brackets
RB = 87,
LC = 88, // left and right curlies (braces)
RC = 89,
LP = 90, // left and right parentheses
RP = 91,
COMMA = 92, // comma operator
ASSIGN = 93, // simple assignment (=)
ASSIGN_BITOR = 94, // |=
ASSIGN_BITXOR = 95, // ^=
ASSIGN_BITAND = 96, // |=
ASSIGN_LSH = 97, // <<=
ASSIGN_RSH = 98, // >>=
ASSIGN_URSH = 99, // >>>=
ASSIGN_ADD = 100, // +=
ASSIGN_SUB = 101, // -=
ASSIGN_MUL = 102, // *=
ASSIGN_DIV = 103, // /=
ASSIGN_MOD = 104, // %=
ASSIGN_EXP = 105; // **=
public static final int FIRST_ASSIGN = ASSIGN,
LAST_ASSIGN = ASSIGN_EXP,
HOOK = 106, // conditional (?:)
COLON = 107,
OR = 108, // logical or (||)
AND = 109, // logical and (&&)
INC = 110, // increment/decrement (++ --)
DEC = 111,
DOT = 112, // member operator (.)
FUNCTION = 113, // function keyword
EXPORT = 114, // export keyword
IMPORT = 115, // import keyword
IF = 116, // if keyword
ELSE = 117, // else keyword
SWITCH = 118, // switch keyword
CASE = 119, // case keyword
DEFAULT = 120, // default keyword
WHILE = 121, // while keyword
DO = 122, // do keyword
FOR = 123, // for keyword
BREAK = 124, // break keyword
CONTINUE = 125, // continue keyword
VAR = 126, // var keyword
WITH = 127, // with keyword
CATCH = 128, // catch keyword
FINALLY = 129, // finally keyword
VOID = 130, // void keyword
RESERVED = 131, // reserved keywords
EMPTY = 132,
/* types used for the parse tree - these never get returned
* by the scanner.
*/
BLOCK = 133, // statement block
LABEL = 134, // label
TARGET = 135,
LOOP = 136,
EXPR_VOID = 137, // expression statement in functions
EXPR_RESULT = 138, // expression statement in scripts
JSR = 139,
SCRIPT = 140, // top-level node for entire script
TYPEOFNAME = 141, // for typeof(simple-name)
USE_STACK = 142,
SETPROP_OP = 143, // x.y op= something
SETELEM_OP = 144, // x[y] op= something
LOCAL_BLOCK = 145,
SET_REF_OP = 146, // *reference op= something
// For XML support:
DOTDOT = 147, // member operator (..)
COLONCOLON = 148, // namespace::name
XML = 149, // XML type
DOTQUERY = 150, // .() -- e.g., x.emps.emp.(name == "terry")
XMLATTR = 151, // @
XMLEND = 152,
// Optimizer-only-tokens
TO_OBJECT = 153,
TO_DOUBLE = 154,
GET = 155, // JS 1.5 get pseudo keyword
SET = 156, // JS 1.5 set pseudo keyword
LET = 157, // JS 1.7 let pseudo keyword
CONST = 158,
SETCONST = 159,
SETCONSTVAR = 160,
ARRAYCOMP = 161, // array comprehension
LETEXPR = 162,
WITHEXPR = 163,
DEBUGGER = 164,
COMMENT = 165,
GENEXPR = 166,
METHOD = 167, // ES6 MethodDefinition
ARROW = 168, // ES6 ArrowFunction
YIELD_STAR = 169, // ES6 "yield *", a specialization of yield
TEMPLATE_LITERAL = 170, // template literal
TEMPLATE_CHARS = 171, // template literal - literal section
TEMPLATE_LITERAL_SUBST = 172, // template literal - substitution
TAGGED_TEMPLATE_LITERAL = 173, // template literal - tagged/handler
DOTDOTDOT = 174, // spread/rest ...
LAST_TOKEN = 174;
/**
* Returns a name for the token. If Rhino is compiled with certain hardcoded debugging flags in
* this file, it calls {@code #typeToName}; otherwise it returns a string whose value is the
* token number.
*/
public static String name(int token) {
if (!printNames) {
return String.valueOf(token);
}
return typeToName(token);
}
/**
* Always returns a human-readable string for the token name. For instance, {@link #FINALLY} has
* the name "FINALLY".
*
* @param token the token code
* @return the actual name for the token code
*/
public static String typeToName(int token) {
switch (token) {
case ERROR:
return "ERROR";
case EOF:
return "EOF";
case EOL:
return "EOL";
case ENTERWITH:
return "ENTERWITH";
case LEAVEWITH:
return "LEAVEWITH";
case RETURN:
return "RETURN";
case GOTO:
return "GOTO";
case IFEQ:
return "IFEQ";
case IFNE:
return "IFNE";
case SETNAME:
return "SETNAME";
case BITOR:
return "BITOR";
case BITXOR:
return "BITXOR";
case BITAND:
return "BITAND";
case EQ:
return "EQ";
case NE:
return "NE";
case LT:
return "LT";
case LE:
return "LE";
case GT:
return "GT";
case GE:
return "GE";
case LSH:
return "LSH";
case RSH:
return "RSH";
case URSH:
return "URSH";
case ADD:
return "ADD";
case SUB:
return "SUB";
case MUL:
return "MUL";
case DIV:
return "DIV";
case MOD:
return "MOD";
case NOT:
return "NOT";
case BITNOT:
return "BITNOT";
case POS:
return "POS";
case NEG:
return "NEG";
case NEW:
return "NEW";
case DELPROP:
return "DELPROP";
case TYPEOF:
return "TYPEOF";
case GETPROP:
return "GETPROP";
case GETPROPNOWARN:
return "GETPROPNOWARN";
case SETPROP:
return "SETPROP";
case GETELEM:
return "GETELEM";
case SETELEM:
return "SETELEM";
case CALL:
return "CALL";
case NAME:
return "NAME";
case NUMBER:
return "NUMBER";
case STRING:
return "STRING";
case NULL:
return "NULL";
case THIS:
return "THIS";
case FALSE:
return "FALSE";
case TRUE:
return "TRUE";
case SHEQ:
return "SHEQ";
case SHNE:
return "SHNE";
case REGEXP:
return "REGEXP";
case BINDNAME:
return "BINDNAME";
case THROW:
return "THROW";
case RETHROW:
return "RETHROW";
case IN:
return "IN";
case INSTANCEOF:
return "INSTANCEOF";
case LOCAL_LOAD:
return "LOCAL_LOAD";
case GETVAR:
return "GETVAR";
case SETVAR:
return "SETVAR";
case CATCH_SCOPE:
return "CATCH_SCOPE";
case ENUM_INIT_KEYS:
return "ENUM_INIT_KEYS";
case ENUM_INIT_VALUES:
return "ENUM_INIT_VALUES";
case ENUM_INIT_ARRAY:
return "ENUM_INIT_ARRAY";
case ENUM_INIT_VALUES_IN_ORDER:
return "ENUM_INIT_VALUES_IN_ORDER";
case ENUM_NEXT:
return "ENUM_NEXT";
case ENUM_ID:
return "ENUM_ID";
case THISFN:
return "THISFN";
case RETURN_RESULT:
return "RETURN_RESULT";
case ARRAYLIT:
return "ARRAYLIT";
case OBJECTLIT:
return "OBJECTLIT";
case GET_REF:
return "GET_REF";
case SET_REF:
return "SET_REF";
case DEL_REF:
return "DEL_REF";
case REF_CALL:
return "REF_CALL";
case REF_SPECIAL:
return "REF_SPECIAL";
case DEFAULTNAMESPACE:
return "DEFAULTNAMESPACE";
case ESCXMLTEXT:
return "ESCXMLTEXT";
case ESCXMLATTR:
return "ESCXMLATTR";
case REF_MEMBER:
return "REF_MEMBER";
case REF_NS_MEMBER:
return "REF_NS_MEMBER";
case REF_NAME:
return "REF_NAME";
case REF_NS_NAME:
return "REF_NS_NAME";
case TRY:
return "TRY";
case SEMI:
return "SEMI";
case LB:
return "LB";
case RB:
return "RB";
case LC:
return "LC";
case RC:
return "RC";
case LP:
return "LP";
case RP:
return "RP";
case COMMA:
return "COMMA";
case ASSIGN:
return "ASSIGN";
case ASSIGN_BITOR:
return "ASSIGN_BITOR";
case ASSIGN_BITXOR:
return "ASSIGN_BITXOR";
case ASSIGN_BITAND:
return "ASSIGN_BITAND";
case ASSIGN_LSH:
return "ASSIGN_LSH";
case ASSIGN_RSH:
return "ASSIGN_RSH";
case ASSIGN_URSH:
return "ASSIGN_URSH";
case ASSIGN_ADD:
return "ASSIGN_ADD";
case ASSIGN_SUB:
return "ASSIGN_SUB";
case ASSIGN_MUL:
return "ASSIGN_MUL";
case ASSIGN_DIV:
return "ASSIGN_DIV";
case ASSIGN_MOD:
return "ASSIGN_MOD";
case ASSIGN_EXP:
return "ASSIGN_EXP";
case HOOK:
return "HOOK";
case COLON:
return "COLON";
case OR:
return "OR";
case AND:
return "AND";
case INC:
return "INC";
case DEC:
return "DEC";
case DOT:
return "DOT";
case FUNCTION:
return "FUNCTION";
case EXPORT:
return "EXPORT";
case IMPORT:
return "IMPORT";
case IF:
return "IF";
case ELSE:
return "ELSE";
case SWITCH:
return "SWITCH";
case CASE:
return "CASE";
case DEFAULT:
return "DEFAULT";
case WHILE:
return "WHILE";
case DO:
return "DO";
case FOR:
return "FOR";
case BREAK:
return "BREAK";
case CONTINUE:
return "CONTINUE";
case VAR:
return "VAR";
case WITH:
return "WITH";
case CATCH:
return "CATCH";
case FINALLY:
return "FINALLY";
case VOID:
return "VOID";
case RESERVED:
return "RESERVED";
case EMPTY:
return "EMPTY";
case BLOCK:
return "BLOCK";
case LABEL:
return "LABEL";
case TARGET:
return "TARGET";
case LOOP:
return "LOOP";
case EXPR_VOID:
return "EXPR_VOID";
case EXPR_RESULT:
return "EXPR_RESULT";
case JSR:
return "JSR";
case SCRIPT:
return "SCRIPT";
case TYPEOFNAME:
return "TYPEOFNAME";
case USE_STACK:
return "USE_STACK";
case SETPROP_OP:
return "SETPROP_OP";
case SETELEM_OP:
return "SETELEM_OP";
case LOCAL_BLOCK:
return "LOCAL_BLOCK";
case SET_REF_OP:
return "SET_REF_OP";
case DOTDOT:
return "DOTDOT";
case COLONCOLON:
return "COLONCOLON";
case XML:
return "XML";
case DOTQUERY:
return "DOTQUERY";
case XMLATTR:
return "XMLATTR";
case XMLEND:
return "XMLEND";
case TO_OBJECT:
return "TO_OBJECT";
case TO_DOUBLE:
return "TO_DOUBLE";
case GET:
return "GET";
case SET:
return "SET";
case LET:
return "LET";
case YIELD:
return "YIELD";
case EXP:
return "EXP";
case CONST:
return "CONST";
case SETCONST:
return "SETCONST";
case ARRAYCOMP:
return "ARRAYCOMP";
case WITHEXPR:
return "WITHEXPR";
case LETEXPR:
return "LETEXPR";
case DEBUGGER:
return "DEBUGGER";
case COMMENT:
return "COMMENT";
case GENEXPR:
return "GENEXPR";
case METHOD:
return "METHOD";
case ARROW:
return "ARROW";
case YIELD_STAR:
return "YIELD_STAR";
case BIGINT:
return "BIGINT";
case TEMPLATE_LITERAL:
return "TEMPLATE_LITERAL";
case TEMPLATE_CHARS:
return "TEMPLATE_CHARS";
case TEMPLATE_LITERAL_SUBST:
return "TEMPLATE_LITERAL_SUBST";
case TAGGED_TEMPLATE_LITERAL:
return "TAGGED_TEMPLATE_LITERAL";
}
// Token without name
throw new IllegalStateException(String.valueOf(token));
}
/**
* Convert a keyword token to a name string for use with the {@link
* Context#FEATURE_RESERVED_KEYWORD_AS_IDENTIFIER} feature.
*
* @param token A token
* @return the corresponding name string
*/
public static String keywordToName(int token) {
switch (token) {
case Token.BREAK:
return "break";
case Token.CASE:
return "case";
case Token.CONTINUE:
return "continue";
case Token.DEFAULT:
return "default";
case Token.DELPROP:
return "delete";
case Token.DO:
return "do";
case Token.ELSE:
return "else";
case Token.FALSE:
return "false";
case Token.FOR:
return "for";
case Token.FUNCTION:
return "function";
case Token.IF:
return "if";
case Token.IN:
return "in";
case Token.LET:
return "let";
case Token.NEW:
return "new";
case Token.NULL:
return "null";
case Token.RETURN:
return "return";
case Token.SWITCH:
return "switch";
case Token.THIS:
return "this";
case Token.TRUE:
return "true";
case Token.TYPEOF:
return "typeof";
case Token.VAR:
return "var";
case Token.VOID:
return "void";
case Token.WHILE:
return "while";
case Token.WITH:
return "with";
case Token.YIELD:
return "yield";
case Token.CATCH:
return "catch";
case Token.CONST:
return "const";
case Token.DEBUGGER:
return "debugger";
case Token.FINALLY:
return "finally";
case Token.INSTANCEOF:
return "instanceof";
case Token.THROW:
return "throw";
case Token.TRY:
return "try";
default:
return null;
}
}
/**
* Return true if the passed code is a valid Token constant.
*
* @param code a potential token code
* @return true if it's a known token
*/
public static boolean isValidToken(int code) {
return code >= ERROR && code <= LAST_TOKEN;
}
}