elvish/pkg/eval/vals/equal.go
Kurtis Rader 3da541c719 Other float64 cases that should be generalized
While pondering issue #1340 I looked at the other `case float64:`
blocks. This change generalizes the few places that need it.

Fixes #1340
2021-06-27 16:32:38 +01:00

116 lines
2.1 KiB
Go

package vals
import (
"math/big"
"reflect"
)
// Equaler wraps the Equal method.
type Equaler interface {
// Equal compares the receiver to another value. Two equal values must have
// the same hash code.
Equal(other interface{}) bool
}
// Equal returns whether two values are equal. It is implemented for the builtin
// types bool and string, the File, List, Map types, StructMap types, and types
// satisfying the Equaler interface. For other types, it uses reflect.DeepEqual
// to compare the two values.
func Equal(x, y interface{}) bool {
switch x := x.(type) {
case nil:
return x == y
case bool:
return x == y
case int:
return x == y
case float64:
return x == y
case *big.Int:
if y, ok := y.(*big.Int); ok {
return x.Cmp(y) == 0
}
return false
case *big.Rat:
if y, ok := y.(*big.Rat); ok {
return x.Cmp(y) == 0
}
return false
case string:
return x == y
case Equaler:
return x.Equal(y)
case File:
if yy, ok := y.(File); ok {
return x.Fd() == yy.Fd()
}
return false
case List:
if yy, ok := y.(List); ok {
return equalList(x, yy)
}
return false
case Map:
if yy, ok := y.(Map); ok {
return equalMap(x, yy)
}
return false
case StructMap:
if yy, ok := y.(StructMap); ok {
return equalStructMap(x, yy)
}
return false
default:
return reflect.DeepEqual(x, y)
}
}
func equalList(x, y List) bool {
if x.Len() != y.Len() {
return false
}
ix := x.Iterator()
iy := y.Iterator()
for ix.HasElem() && iy.HasElem() {
if !Equal(ix.Elem(), iy.Elem()) {
return false
}
ix.Next()
iy.Next()
}
return true
}
func equalMap(x, y Map) bool {
if x.Len() != y.Len() {
return false
}
for it := x.Iterator(); it.HasElem(); it.Next() {
k, vx := it.Elem()
vy, ok := y.Index(k)
if !ok || !Equal(vx, vy) {
return false
}
}
return true
}
func equalStructMap(x, y StructMap) bool {
t := reflect.TypeOf(x)
if t != reflect.TypeOf(y) {
return false
}
xValue := reflect.ValueOf(x)
yValue := reflect.ValueOf(y)
it := iterateStructMap(t)
for it.Next() {
_, xField := it.Get(xValue)
_, yField := it.Get(yValue)
if !Equal(xField, yField) {
return false
}
}
return true
}