mirror of https://github.com/status-im/consul.git
100 lines
2.5 KiB
Go
100 lines
2.5 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 provides functionality for identifying function types.
|
|
package function
|
|
|
|
import (
|
|
"reflect"
|
|
"regexp"
|
|
"runtime"
|
|
"strings"
|
|
)
|
|
|
|
type funcType int
|
|
|
|
const (
|
|
_ funcType = iota
|
|
|
|
tbFunc // func(T) bool
|
|
ttbFunc // func(T, T) bool
|
|
trbFunc // func(T, R) 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
|
|
ValuePredicate = tbFunc // func(T) bool
|
|
KeyValuePredicate = trbFunc // func(T, R) 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 tbFunc: // func(T) bool
|
|
if ni == 1 && no == 1 && t.Out(0) == boolType {
|
|
return true
|
|
}
|
|
case ttbFunc: // func(T, T) bool
|
|
if ni == 2 && no == 1 && t.In(0) == t.In(1) && t.Out(0) == boolType {
|
|
return true
|
|
}
|
|
case trbFunc: // func(T, R) bool
|
|
if ni == 2 && no == 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
|
|
}
|
|
|
|
var lastIdentRx = regexp.MustCompile(`[_\p{L}][_\p{L}\p{N}]*$`)
|
|
|
|
// NameOf returns the name of the function value.
|
|
func NameOf(v reflect.Value) string {
|
|
fnc := runtime.FuncForPC(v.Pointer())
|
|
if fnc == nil {
|
|
return "<unknown>"
|
|
}
|
|
fullName := fnc.Name() // e.g., "long/path/name/mypkg.(*MyType).(long/path/name/mypkg.myMethod)-fm"
|
|
|
|
// Method closures have a "-fm" suffix.
|
|
fullName = strings.TrimSuffix(fullName, "-fm")
|
|
|
|
var name string
|
|
for len(fullName) > 0 {
|
|
inParen := strings.HasSuffix(fullName, ")")
|
|
fullName = strings.TrimSuffix(fullName, ")")
|
|
|
|
s := lastIdentRx.FindString(fullName)
|
|
if s == "" {
|
|
break
|
|
}
|
|
name = s + "." + name
|
|
fullName = strings.TrimSuffix(fullName, s)
|
|
|
|
if i := strings.LastIndexByte(fullName, '('); inParen && i >= 0 {
|
|
fullName = fullName[:i]
|
|
}
|
|
fullName = strings.TrimSuffix(fullName, ".")
|
|
}
|
|
return strings.TrimSuffix(name, ".")
|
|
}
|