1/* 2* Conditions Of Use 3* 4* This software was developed by employees of the National Institute of 5* Standards and Technology (NIST), an agency of the Federal Government. 6* Pursuant to title 15 Untied States Code Section 105, works of NIST 7* employees are not subject to copyright protection in the United States 8* and are considered to be in the public domain. As a result, a formal 9* license is not needed to use the software. 10* 11* This software is provided by NIST as a service and is expressly 12* provided "AS IS." NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED 13* OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF 14* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT 15* AND DATA ACCURACY. NIST does not warrant or make any representations 16* regarding the use of the software or the results thereof, including but 17* not limited to the correctness, accuracy, reliability or usefulness of 18* the software. 19* 20* Permission to use this software is contingent upon your acceptance 21* of the terms of this agreement 22* 23* . 24* 25*/ 26package gov.nist.core; 27 28import java.text.ParseException; 29 30/** Generic parser class. 31* All parsers inherit this class. 32* 33*@version 1.2 34* 35*@author M. Ranganathan <br/> 36* 37* 38* 39*/ 40public abstract class ParserCore { 41 public static final boolean debug = Debug.parserDebug; 42 43 static int nesting_level; 44 45 protected LexerCore lexer; 46 47 48 protected NameValue nameValue(char separator) throws ParseException { 49 if (debug) dbg_enter("nameValue"); 50 try { 51 52 lexer.match(LexerCore.ID); 53 Token name = lexer.getNextToken(); 54 // eat white space. 55 lexer.SPorHT(); 56 try { 57 58 59 boolean quoted = false; 60 61 char la = lexer.lookAhead(0); 62 63 if (la == separator ) { 64 lexer.consume(1); 65 lexer.SPorHT(); 66 String str = null; 67 boolean isFlag = false; 68 if (lexer.lookAhead(0) == '\"') { 69 str = lexer.quotedString(); 70 quoted = true; 71 } else { 72 lexer.match(LexerCore.ID); 73 Token value = lexer.getNextToken(); 74 str = value.tokenValue; 75 76 // JvB: flag parameters must be empty string! 77 if (str==null) { 78 str = ""; 79 isFlag = true; 80 } 81 } 82 NameValue nv = new NameValue(name.tokenValue,str,isFlag); 83 if (quoted) nv.setQuotedValue(); 84 return nv; 85 } else { 86 // JvB: flag parameters must be empty string! 87 return new NameValue(name.tokenValue,"",true); 88 } 89 } catch (ParseException ex) { 90 return new NameValue(name.tokenValue,null,false); 91 } 92 93 } finally { 94 if (debug) dbg_leave("nameValue"); 95 } 96 97 98 } 99 100 protected void dbg_enter(String rule) { 101 StringBuffer stringBuffer = new StringBuffer(); 102 for (int i = 0; i < nesting_level ; i++) 103 stringBuffer.append(">"); 104 105 if (debug) { 106 System.out.println( 107 stringBuffer + rule + 108 "\nlexer buffer = \n" + 109 lexer.getRest()); 110 } 111 nesting_level++; 112 } 113 114 protected void dbg_leave(String rule) { 115 StringBuffer stringBuffer = new StringBuffer(); 116 for (int i = 0; i < nesting_level ; i++) 117 stringBuffer.append("<"); 118 119 if (debug) { 120 System.out.println( 121 stringBuffer + 122 rule + 123 "\nlexer buffer = \n" + 124 lexer.getRest()); 125 } 126 nesting_level --; 127 } 128 129 protected NameValue nameValue() throws ParseException { 130 return nameValue('='); 131 } 132 133 134 135 protected void peekLine(String rule) { 136 if (debug) { 137 Debug.println(rule +" " + lexer.peekLine()); 138 } 139 } 140} 141 142 143