ParserTables


1   package fri.patterns.interpreter.parsergenerator;
2   
3   import java.util.List  ;
4   import java.util.Map  ;
5   import java.io.PrintStream  ;
6   import fri.patterns.interpreter.parsergenerator.syntax.Syntax;
7   
8   /**
9       Responsibilities of (bottom-up) parser tables, that must provide:
10      <ul>
11          <li>all terminals, without EPSILON (for the Lexer)</li>
12          <li>the syntax</li>
13          <li>the follow-state from the GOTO-table</li>
14          <li>the follow action from the PARSE-ACTION-table</li>
15          <li>a list of expected terminals</li>
16      </ul>
17  
18      @author (c) 2000, Fritz Ritzberger
19  */
20  
21  public interface ParserTables
22  {
23      /** Special symbol occuring in a parser table, 0, means: syntax was correct when coming to that cell. */
24      public static final Integer   ACCEPT = new Integer  (0);
25      
26      /** Special symbol occuring in a parser table, -1, means: error when coming to that cell. */
27      public static final Integer   ERROR = new Integer  (-1);
28  
29      /** Special symbol occuring in a parser table, -2, means: read next token. */
30      public static final Integer   SHIFT = new Integer  (-2);
31      
32  
33      /**
34          Returns the next state from the GOTO-table, for a given state and a received terminal or nonterminal.
35          @param currentState the current parser state
36          @param symbol recently received terminal or nonterminal
37          @return new parser state
38      */
39      public Integer   getGotoState(Integer   currentState, String   symbol);
40  
41      /**
42          Returns the action from the PARSE-ACTION-table, for a given state and received terminal.
43          fuer einen gegebenen Zustand und ein Terminal.
44          @param currentState the current parser state
45          @param terminal recently received terminal
46          @return new action to proceed, SHIFT, ACCEPT, ERROR, or anything above zero, meaning REDUCE.
47      */
48      public Integer   getParseAction(Integer   currentState, String   terminal);
49  
50      /**
51          Returns the List of treminals, without EPSILON.
52      */
53      public List   getTerminals();
54      
55      /**
56          Returns the input syntax.
57      */
58      public Syntax getSyntax();
59  
60      /**
61          Dumps rules, GOTO-table, PARSE-ACTION-table, FIRST and FOLLOW sets, ...
62      */
63      public void dump(PrintStream   out);
64      
65      /**
66          The keySet of returned Map contains all expected terminals for the current state.
67          These can be used as Lexer hints.
68      */
69      public Map   getExpected(Integer   state);
70  
71  }
72
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags