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
66
67
68
69
70
71
72
73
74
75
76
77
|
package bjc.pratt.commands;
import bjc.pratt.ParseBlock;
import bjc.pratt.ParserContext;
import bjc.pratt.Token;
import bjc.utils.data.ITree;
import bjc.utils.data.Tree;
import bjc.utils.parserutils.ParserException;
/**
* A ternary command, like C's ?:
*
* @author bjculkin
*
* @param <K>
* The key type of the tokens.
*
* @param <V>
* The value type of the tokens.
*
* @param <C>
* The state type of the parser.
*/
public class TernaryCommand<K, V, C> extends BinaryPostCommand<K, V, C> {
private final ParseBlock<K, V, C> innerBlck;
private final Token<K, V> mark;
private final boolean nonassoc;
/**
* Create a new ternary command.
*
* @param precedence
* The precedence of this operator.
*
* @param innerBlock
* The representation of the inner block of the
* expression.
*
* @param marker
* The token to use as the root of the AST node.
*
* @param isNonassoc
* Whether or not the conditional is associative.
*/
public TernaryCommand(final int precedence, final ParseBlock<K, V, C> innerBlock, final Token<K, V> marker,
final boolean isNonassoc) {
super(precedence);
if (innerBlock == null)
throw new NullPointerException("Inner block must not be null");
else if (marker == null) throw new NullPointerException("Marker must not be null");
innerBlck = innerBlock;
mark = marker;
nonassoc = isNonassoc;
}
@Override
public ITree<Token<K, V>> denote(final ITree<Token<K, V>> operand, final Token<K, V> operator,
final ParserContext<K, V, C> ctx) throws ParserException {
final ITree<Token<K, V>> inner = innerBlck.parse(ctx);
final ITree<Token<K, V>> outer = ctx.parse.parseExpression(1 + leftBinding(), ctx.tokens, ctx.state,
false);
return new Tree<>(mark, inner, operand, outer);
}
@Override
public int nextBinding() {
if (nonassoc) return leftBinding() - 1;
return leftBinding();
}
}
|
