ParserState


1   /*****************************************************************************
2    * Copyright (C) Zephyr Business Solutions Corp. All rights reserved.            *
3    * ------------------------------------------------------------------------- *
4    * The software in this package is published under the terms of the BSD      *
5    * style license a copy of which has been included with this distribution in *
6    * the LICENSE.txt file.                                                     *
7    *****************************************************************************/
8   /*
9    * Created on 2004-11-11
10   *
11   * Author Ben Yu
12   */
13  package jfun.parsec;
14  
15  
16  /**
17   * @author Ben Yu
18   *
19   * 2004-11-11
20   */
21  final class ParserState extends ParseContext{
22    
23    private final Tok[] input;
24    private final ParsecError[] sys_unexpected;
25    //in case a terminating eof token is not explicitly created,
26    //the implicit one is used.
27    private final int end_index;
28    private final ParsecError eof_unexpected;
29    
30    
31    private final ShowToken show;
32  
33    boolean isEof(){
34      return at >= input.length; //|| input[at].getToken()==Tokens.eof();
35    }
36    int length(){return input.length;}
37    int getIndex(){
38      if(at==input.length) return end_index;
39      return input[at].getIndex();
40    }
41    
42  
43    Tok getToken(){
44      return input[at];
45    }
46    //caller should not change input after it is passed in.
47    ParserState(final Object   us, final Tok[] input,
48        final int at, final String   module, final PositionMap pmap,
49        final int end_index, 
50        final String   eof_str, final ShowToken show){
51      super(us, at, module, pmap);
52      this.input = input;
53      this.sys_unexpected = new ParsecError[input.length];
54      this.show = show;
55      this.end_index = end_index;
56      this.eof_unexpected = ParsecError.raiseSysUnexpected(
57          end_index, eof_str);
58    }
59    ParserState(final Object   r, final Object   us, final Tok[] input,
60        final int at, final String   module, final PositionMap pmap,
61        final int end_index, 
62        final String   eof_str, final ShowToken show){
63      super(r, us, at, module, pmap);
64      this.input = input;
65      this.sys_unexpected = new ParsecError[input.length];
66      this.show = show;
67      this.end_index = end_index;
68      this.eof_unexpected = ParsecError.raiseSysUnexpected(
69          end_index, eof_str);
70    }
71  
72    ParsecError getSysUnexpected(){
73      return getSysUnexpected(at);
74    }
75    private ParsecError getSysUnexpected(final int i){
76      if(i>=sys_unexpected.length) return eof_unexpected;
77      ParsecError r = sys_unexpected[i];
78      if(r == null){
79        final Tok ptok = input[i];
80        r = ParsecError.raiseSysUnexpected(ptok.getIndex(), 
81            show.show(ptok.getToken()));
82        sys_unexpected[i] = r;
83      }
84      return r;
85    }
86    char peekChar(){
87      throw new IllegalStateException  ("parser not on char level.");
88    }
89    char peekChar(int i){
90      throw new IllegalStateException  ("parser not on char level.");
91    }
92    CharSequence   getSource(){
93      throw new IllegalStateException  ("parser not on char level.");
94    }
95  }
96
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags