mirror of https://github.com/docker/cli.git
50 lines
1.2 KiB
Go
50 lines
1.2 KiB
Go
|
// Copyright 2017, The Go Authors. All rights reserved.
|
||
|
|
// Use of this source code is governed by a BSD-style
|
||
|
|
// license that can be found in the LICENSE.md file.
|
||
|
|
|
||
|
|
// Package function identifies function types.
|
||
|
|
package function
|
||
|
|
|
||
|
|
import "reflect"
|
||
|
|
|
||
|
|
type funcType int
|
||
|
|
|
||
|
|
const (
|
||
|
|
_ funcType = iota
|
||
|
|
|
||
|
|
ttbFunc // func(T, T) bool
|
||
|
|
tibFunc // func(T, I) bool
|
||
|
|
trFunc // func(T) R
|
||
|
|
|
||
|
|
Equal = ttbFunc // func(T, T) bool
|
||
|
|
EqualAssignable = tibFunc // func(T, I) bool; encapsulates func(T, T) bool
|
||
|
|
Transformer = trFunc // func(T) R
|
||
|
|
ValueFilter = ttbFunc // func(T, T) bool
|
||
|
|
Less = ttbFunc // func(T, T) bool
|
||
|
|
)
|
||
|
|
|
||
|
|
var boolType = reflect.TypeOf(true)
|
||
|
|
|
||
|
|
// IsType reports whether the reflect.Type is of the specified function type.
|
||
|
|
func IsType(t reflect.Type, ft funcType) bool {
|
||
|
|
if t == nil || t.Kind() != reflect.Func || t.IsVariadic() {
|
||
|
|
return false
|
||
|
|
}
|
||
|
|
ni, no := t.NumIn(), t.NumOut()
|
||
|
|
switch ft {
|
||
|
|
case ttbFunc: // func(T, T) bool
|
||
|
|
if ni == 2 && no == 1 && t.In(0) == t.In(1) && t.Out(0) == boolType {
|
||
|
|
return true
|
||
|
|
}
|
||
|
|
case tibFunc: // func(T, I) bool
|
||
|
|
if ni == 2 && no == 1 && t.In(0).AssignableTo(t.In(1)) && t.Out(0) == boolType {
|
||
|
|
return true
|
||
|
|
}
|
||
|
|
case trFunc: // func(T) R
|
||
|
|
if ni == 1 && no == 1 {
|
||
|
|
return true
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return false
|
||
|
|
}
|