127 lines
3.6 KiB
Go
127 lines
3.6 KiB
Go
// Copyright 2019 The Hugo Authors. All rights reserved.
|
|
// Some functions in this file (see comments) is based on the Go source code,
|
|
// copyright The Go Authors and governed by a BSD-style license.
|
|
//
|
|
// 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 hreflect contains reflect helpers.
|
|
package hreflect
|
|
|
|
import (
|
|
"reflect"
|
|
|
|
"github.com/gohugoio/hugo/common/types"
|
|
)
|
|
|
|
// TODO(bep) replace the private versions in /tpl with these.
|
|
// IsInt returns whether the given kind is a number.
|
|
func IsNumber(kind reflect.Kind) bool {
|
|
return IsInt(kind) || IsUint(kind) || IsFloat(kind)
|
|
}
|
|
|
|
// IsInt returns whether the given kind is an int.
|
|
func IsInt(kind reflect.Kind) bool {
|
|
switch kind {
|
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
// IsUint returns whether the given kind is an uint.
|
|
func IsUint(kind reflect.Kind) bool {
|
|
switch kind {
|
|
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
// IsFloat returns whether the given kind is a float.
|
|
func IsFloat(kind reflect.Kind) bool {
|
|
switch kind {
|
|
case reflect.Float32, reflect.Float64:
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
// IsTruthful returns whether in represents a truthful value.
|
|
// See IsTruthfulValue
|
|
func IsTruthful(in interface{}) bool {
|
|
switch v := in.(type) {
|
|
case reflect.Value:
|
|
return IsTruthfulValue(v)
|
|
default:
|
|
return IsTruthfulValue(reflect.ValueOf(in))
|
|
}
|
|
}
|
|
|
|
var zeroType = reflect.TypeOf((*types.Zeroer)(nil)).Elem()
|
|
|
|
// IsTruthfulValue returns whether the given value has a meaningful truth value.
|
|
// This is based on template.IsTrue in Go's stdlib, but also considers
|
|
// IsZero and any interface value will be unwrapped before it's considered
|
|
// for truthfulness.
|
|
//
|
|
// Based on:
|
|
// https://github.com/golang/go/blob/178a2c42254166cffed1b25fb1d3c7a5727cada6/src/text/template/exec.go#L306
|
|
func IsTruthfulValue(val reflect.Value) (truth bool) {
|
|
val = indirectInterface(val)
|
|
|
|
if !val.IsValid() {
|
|
// Something like var x interface{}, never set. It's a form of nil.
|
|
return
|
|
}
|
|
|
|
if val.Type().Implements(zeroType) {
|
|
return !val.Interface().(types.Zeroer).IsZero()
|
|
}
|
|
|
|
switch val.Kind() {
|
|
case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
|
|
truth = val.Len() > 0
|
|
case reflect.Bool:
|
|
truth = val.Bool()
|
|
case reflect.Complex64, reflect.Complex128:
|
|
truth = val.Complex() != 0
|
|
case reflect.Chan, reflect.Func, reflect.Ptr, reflect.Interface:
|
|
truth = !val.IsNil()
|
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
|
truth = val.Int() != 0
|
|
case reflect.Float32, reflect.Float64:
|
|
truth = val.Float() != 0
|
|
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
|
|
truth = val.Uint() != 0
|
|
case reflect.Struct:
|
|
truth = true // Struct values are always true.
|
|
default:
|
|
return
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
// Based on: https://github.com/golang/go/blob/178a2c42254166cffed1b25fb1d3c7a5727cada6/src/text/template/exec.go#L931
|
|
func indirectInterface(v reflect.Value) reflect.Value {
|
|
if v.Kind() != reflect.Interface {
|
|
return v
|
|
}
|
|
if v.IsNil() {
|
|
return reflect.Value{}
|
|
}
|
|
return v.Elem()
|
|
}
|