6 changed files with 218 additions and 197 deletions
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@@ -0,0 +1,212 @@
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/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ |
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/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */ |
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/* Copyright 2014 Mozilla Foundation |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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*/ |
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/* globals EOF, error, Lexer */ |
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'use strict'; |
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var PostScriptParser = (function PostScriptParserClosure() { |
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function PostScriptParser(lexer) { |
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this.lexer = lexer; |
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this.operators = []; |
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this.token = null; |
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this.prev = null; |
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} |
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PostScriptParser.prototype = { |
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nextToken: function PostScriptParser_nextToken() { |
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this.prev = this.token; |
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this.token = this.lexer.getToken(); |
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}, |
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accept: function PostScriptParser_accept(type) { |
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if (this.token.type == type) { |
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this.nextToken(); |
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return true; |
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} |
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return false; |
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}, |
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expect: function PostScriptParser_expect(type) { |
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if (this.accept(type)) |
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return true; |
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error('Unexpected symbol: found ' + this.token.type + ' expected ' + |
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type + '.'); |
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}, |
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parse: function PostScriptParser_parse() { |
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this.nextToken(); |
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this.expect(PostScriptTokenTypes.LBRACE); |
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this.parseBlock(); |
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this.expect(PostScriptTokenTypes.RBRACE); |
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return this.operators; |
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}, |
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parseBlock: function PostScriptParser_parseBlock() { |
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while (true) { |
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if (this.accept(PostScriptTokenTypes.NUMBER)) { |
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this.operators.push(this.prev.value); |
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} else if (this.accept(PostScriptTokenTypes.OPERATOR)) { |
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this.operators.push(this.prev.value); |
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} else if (this.accept(PostScriptTokenTypes.LBRACE)) { |
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this.parseCondition(); |
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} else { |
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return; |
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} |
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} |
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}, |
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parseCondition: function PostScriptParser_parseCondition() { |
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// Add two place holders that will be updated later
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var conditionLocation = this.operators.length; |
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this.operators.push(null, null); |
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this.parseBlock(); |
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this.expect(PostScriptTokenTypes.RBRACE); |
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if (this.accept(PostScriptTokenTypes.IF)) { |
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// The true block is right after the 'if' so it just falls through on
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// true else it jumps and skips the true block.
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this.operators[conditionLocation] = this.operators.length; |
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this.operators[conditionLocation + 1] = 'jz'; |
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} else if (this.accept(PostScriptTokenTypes.LBRACE)) { |
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var jumpLocation = this.operators.length; |
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this.operators.push(null, null); |
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var endOfTrue = this.operators.length; |
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this.parseBlock(); |
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this.expect(PostScriptTokenTypes.RBRACE); |
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this.expect(PostScriptTokenTypes.IFELSE); |
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// The jump is added at the end of the true block to skip the false
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// block.
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this.operators[jumpLocation] = this.operators.length; |
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this.operators[jumpLocation + 1] = 'j'; |
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this.operators[conditionLocation] = endOfTrue; |
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this.operators[conditionLocation + 1] = 'jz'; |
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} else { |
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error('PS Function: error parsing conditional.'); |
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} |
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} |
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}; |
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return PostScriptParser; |
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})(); |
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var PostScriptTokenTypes = { |
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LBRACE: 0, |
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RBRACE: 1, |
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NUMBER: 2, |
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OPERATOR: 3, |
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IF: 4, |
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IFELSE: 5 |
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}; |
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var PostScriptToken = (function PostScriptTokenClosure() { |
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function PostScriptToken(type, value) { |
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this.type = type; |
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this.value = value; |
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} |
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var opCache = {}; |
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PostScriptToken.getOperator = function PostScriptToken_getOperator(op) { |
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var opValue = opCache[op]; |
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if (opValue) |
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return opValue; |
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return opCache[op] = new PostScriptToken(PostScriptTokenTypes.OPERATOR, op); |
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}; |
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PostScriptToken.LBRACE = new PostScriptToken(PostScriptTokenTypes.LBRACE, |
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'{'); |
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PostScriptToken.RBRACE = new PostScriptToken(PostScriptTokenTypes.RBRACE, |
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'}'); |
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PostScriptToken.IF = new PostScriptToken(PostScriptTokenTypes.IF, 'IF'); |
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PostScriptToken.IFELSE = new PostScriptToken(PostScriptTokenTypes.IFELSE, |
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'IFELSE'); |
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return PostScriptToken; |
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})(); |
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var PostScriptLexer = (function PostScriptLexerClosure() { |
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function PostScriptLexer(stream) { |
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this.stream = stream; |
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this.nextChar(); |
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} |
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PostScriptLexer.prototype = { |
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nextChar: function PostScriptLexer_nextChar() { |
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return (this.currentChar = this.stream.getByte()); |
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}, |
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getToken: function PostScriptLexer_getToken() { |
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var s = ''; |
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var comment = false; |
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var ch = this.currentChar; |
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// skip comments
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while (true) { |
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if (ch < 0) { |
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return EOF; |
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} |
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if (comment) { |
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if (ch === 0x0A || ch === 0x0D) { |
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comment = false; |
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} |
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} else if (ch == 0x25) { // '%'
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comment = true; |
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} else if (!Lexer.isSpace(ch)) { |
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break; |
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} |
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ch = this.nextChar(); |
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} |
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switch (ch | 0) { |
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case 0x30: case 0x31: case 0x32: case 0x33: case 0x34: // '0'-'4'
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case 0x35: case 0x36: case 0x37: case 0x38: case 0x39: // '5'-'9'
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case 0x2B: case 0x2D: case 0x2E: // '+', '-', '.'
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return new PostScriptToken(PostScriptTokenTypes.NUMBER, |
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this.getNumber()); |
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case 0x7B: // '{'
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this.nextChar(); |
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return PostScriptToken.LBRACE; |
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case 0x7D: // '}'
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this.nextChar(); |
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return PostScriptToken.RBRACE; |
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} |
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// operator
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var str = String.fromCharCode(ch); |
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while ((ch = this.nextChar()) >= 0 && // and 'A'-'Z', 'a'-'z'
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((ch >= 0x41 && ch <= 0x5A) || (ch >= 0x61 && ch <= 0x7A))) { |
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str += String.fromCharCode(ch); |
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} |
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switch (str.toLowerCase()) { |
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case 'if': |
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return PostScriptToken.IF; |
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case 'ifelse': |
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return PostScriptToken.IFELSE; |
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default: |
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return PostScriptToken.getOperator(str); |
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} |
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}, |
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getNumber: function PostScriptLexer_getNumber() { |
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var ch = this.currentChar; |
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var str = String.fromCharCode(ch); |
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while ((ch = this.nextChar()) >= 0) { |
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if ((ch >= 0x30 && ch <= 0x39) || // '0'-'9'
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ch === 0x2D || ch === 0x2E) { // '-', '.'
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str += String.fromCharCode(ch); |
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} else { |
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break; |
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} |
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} |
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var value = parseFloat(str); |
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if (isNaN(value)) |
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error('Invalid floating point number: ' + value); |
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return value; |
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} |
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}; |
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return PostScriptLexer; |
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})(); |
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