-
Notifications
You must be signed in to change notification settings - Fork 26
/
desc.go
57 lines (48 loc) · 1.51 KB
/
desc.go
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
// Copyright 2015 Matthew Collins
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package entitysys
import "reflect"
// Matcher is used to select when an entity is used for a
// system.
type Matcher interface {
Match(e interface{}) bool
}
type typeMatcher struct {
Type reflect.Type
}
func (t typeMatcher) Match(e interface{}) bool {
if t.Type.Kind() == reflect.Interface {
return reflect.TypeOf(e).Implements(t.Type)
}
_, ok := reflect.TypeOf(e).Elem().FieldByName(t.Type.Elem().Name())
return ok
}
// Type returns a Matcher that matches when the type of element
// of the passed to this is implemented by the entity.
//
// This method should be used as followed for interfaces
// Type((*MyInterface)(nil))
func Type(t interface{}) Matcher {
return typeMatcher{
Type: reflect.TypeOf(t).Elem(),
}
}
type notMatcher struct {
child Matcher
}
func (n notMatcher) Match(e interface{}) bool { return !n.child.Match(e) }
// Not inverts the passed Matcher.
func Not(d Matcher) Matcher {
return notMatcher{child: d}
}