blob: 74a3d96676ef074281760bb017f9b4b232c773d3 (
plain)
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
|
package decor
// OnCondition applies decorator only if a condition is true.
//
// `decorator` Decorator
//
// `cond` bool
//
func OnCondition(decorator Decorator, cond bool) Decorator {
return Conditional(cond, decorator, nil)
}
// OnPredicate applies decorator only if a predicate evaluates to true.
//
// `decorator` Decorator
//
// `predicate` func() bool
//
func OnPredicate(decorator Decorator, predicate func() bool) Decorator {
return Predicative(predicate, decorator, nil)
}
// Conditional returns decorator `a` if condition is true, otherwise
// decorator `b`.
//
// `cond` bool
//
// `a` Decorator
//
// `b` Decorator
//
func Conditional(cond bool, a, b Decorator) Decorator {
if cond {
return a
} else {
return b
}
}
// Predicative returns decorator `a` if predicate evaluates to true,
// otherwise decorator `b`.
//
// `predicate` func() bool
//
// `a` Decorator
//
// `b` Decorator
//
func Predicative(predicate func() bool, a, b Decorator) Decorator {
if predicate() {
return a
} else {
return b
}
}
|