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
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.searchlib.rankingexpression.rule;
import com.yahoo.searchlib.rankingexpression.Reference;
import com.yahoo.searchlib.rankingexpression.evaluation.Context;
import com.yahoo.searchlib.rankingexpression.evaluation.Value;
import com.yahoo.tensor.TensorType;
import com.yahoo.tensor.evaluation.TypeContext;
import java.util.Deque;
import java.util.List;
import java.util.Objects;
/**
* A conditional branch of a ranking expression.
*
* @author Simon Thoresen Hult
* @author bratseth
*/
public final class IfNode extends CompositeNode {
/** [condition, trueExpression, falseExpression] */
private final List<ExpressionNode> arguments;
private final Double trueProbability;
public IfNode(ExpressionNode condition, ExpressionNode trueExpression, ExpressionNode falseExpression) {
this(condition, trueExpression, falseExpression, null);
}
/**
* Creates a new condition node.
*
* @param condition the condition of this
* @param trueExpression the expression to evaluate if the comparison is true
* @param falseExpression the expression to evaluate if the comparison is false
* @param trueProbability the probability that the condition will evaluate to true, or null if not known.
* @throws IllegalArgumentException if trueProbability is non-null and not between 0.0 and 1.0
*/
public IfNode(ExpressionNode condition, ExpressionNode trueExpression, ExpressionNode falseExpression,
Double trueProbability) {
if (trueProbability != null && ( trueProbability < 0.0 || trueProbability > 1.0) )
throw new IllegalArgumentException("trueProbability must be a between 0.0 and 1.0, not " + trueProbability);
this.trueProbability = trueProbability;
this.arguments = List.of(condition, trueExpression, falseExpression);
}
@Override
public List<ExpressionNode> children() {
return arguments;
}
public ExpressionNode getCondition() { return arguments.get(0); }
public ExpressionNode getTrueExpression() { return arguments.get(1); }
public ExpressionNode getFalseExpression() { return arguments.get(2); }
/** The average probability that the condition of this node will evaluate to true, or null if not known */
public Double getTrueProbability() { return trueProbability; }
@Override
public StringBuilder toString(StringBuilder string, SerializationContext context, Deque<String> path, CompositeNode parent) {
string.append("if (");
getCondition().toString(string, context, path, this).append(", ");
getTrueExpression().toString(string, context, path, this).append(", ");
getFalseExpression().toString(string, context, path, this);
if (trueProbability != null) {
string.append(", ").append(trueProbability);
}
return string.append(')');
}
@Override
public TensorType type(TypeContext<Reference> context) {
TensorType trueType = getTrueExpression().type(context);
TensorType falseType = getFalseExpression().type(context);
return trueType.dimensionwiseGeneralizationWith(falseType).orElseThrow(() ->
new IllegalArgumentException("An if expression must produce compatible types in both " +
"alternatives, but the 'true' type is " + trueType + " while the " +
"'false' type is " + falseType +
"\n'true' branch: " + getTrueExpression() +
"\n'false' branch: " + getFalseExpression())
);
}
@Override
public Value evaluate(Context context) {
if (getCondition().evaluate(context).asBoolean())
return getTrueExpression().evaluate(context);
else
return getFalseExpression().evaluate(context);
}
@Override
public IfNode setChildren(List<ExpressionNode> children) {
if (children.size() != 3) throw new IllegalArgumentException("Expected 3 children but got " + children.size());
return new IfNode(children.get(0), children.get(1), children.get(2));
}
@Override
public int hashCode() { return Objects.hash("if", arguments, trueProbability); }
}
|
