blob: 4de9ae46dc9fc4548a8a1c954ecbed2166804c70 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package cfgparser;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import org.antlr.v4.runtime.ANTLRFileStream;
import org.antlr.v4.runtime.BufferedTokenStream;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.tree.ParseTreeWalker;
import parser.Rule;
/**
*
* @author edwajohn
*/
public class Grammar {
private String name;
private ArrayList<Rule> rules;
private String startSymbol;
public Grammar(String filename) throws IOException {
GrammarLexer cfglexer = new GrammarLexer(new ANTLRFileStream(filename));
GrammarParser cfgparser = new GrammarParser(new BufferedTokenStream(cfglexer));
ParserRuleContext tree = cfgparser.getContext(); // parse
GrammarParser.GoalContext context = cfgparser.goal();
// Walk it and attach our listener
GrammarListenerImpl listener = new GrammarListenerImpl();
ParseTreeWalker walker = new ParseTreeWalker();
walker.walk(listener, context);
name = listener.name;
rules = listener.rules;
startSymbol = listener.startSymbol;
}
public ArrayList<Rule> getRules() {
return rules;
}
public String getName() {
return name;
}
public ArrayList<String> getSymbols() {
HashSet<String> symbols = new HashSet<>();
for (Rule rule : rules) {
symbols.add(rule.getLhs());
for (String symbol : rule.getRhs()) {
symbols.add(symbol);
}
}
return new ArrayList<>(symbols);
}
public String getStartSymbol() {
return startSymbol;
}
}
|
