mirror of
https://github.com/golang/go
synced 2024-11-22 14:04:48 -07:00
reflect: add iterative related methods
Fixes #66056
Change-Id: I1e24636e43e68cd57576c39b014e0826fb6c322c
GitHub-Last-Rev: 319ad8ea7c
GitHub-Pull-Request: golang/go#66824
Reviewed-on: https://go-review.googlesource.com/c/go/+/578815
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This commit is contained in:
qiulaidongfeng
Gopher Robot
parent
49eedfb4d0
commit
524a774634
4
api/next/66056.txt
Normal file
4
api/next/66056.txt
Normal file
@ -0,0 +1,4 @@
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pkg reflect, method (Value) Seq() iter.Seq[Value] #66056
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pkg reflect, method (Value) Seq2() iter.Seq2[Value, Value] #66056
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pkg reflect, type Type interface, CanSeq() bool #66056
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pkg reflect, type Type interface, CanSeq2() bool #66056
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4
doc/next/6-stdlib/99-minor/reflect/66056.md
Normal file
4
doc/next/6-stdlib/99-minor/reflect/66056.md
Normal file
@ -0,0 +1,4 @@
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The new methods [Value.Seq] and [Value.Seq2] return sequences that iterate over the value
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as though it were used in a for/range loop.
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The new methods [Type.CanSeq] and [Type.CanSeq2] report whether calling
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[Value.Seq] and [Value.Seq2], respectively, will succeed without panicking.
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140
src/reflect/iter.go
Normal file
140
src/reflect/iter.go
Normal file
@ -0,0 +1,140 @@
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// Copyright 2024 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package reflect
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import "iter"
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// Seq returns an iter.Seq[reflect.Value] that loops over the elements of v.
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// If v's kind is Func, it must be a function that has no results and
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// that takes a single argument of type func(T) bool for some type T.
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// If v's kind is Pointer, the pointer element type must have kind Array.
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// Otherwise v's kind must be Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr,
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// Array, Chan, Map, Slice, or String.
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func (v Value) Seq() iter.Seq[Value] {
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if canRangeFunc(v.typ()) {
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return func(yield func(Value) bool) {
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rf := MakeFunc(v.Type().In(0), func(in []Value) []Value {
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return []Value{ValueOf(yield(in[0]))}
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})
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v.Call([]Value{rf})
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}
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}
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switch v.Kind() {
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case Int, Int8, Int16, Int32, Int64:
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return func(yield func(Value) bool) {
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for i := range v.Int() {
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if !yield(ValueOf(i)) {
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return
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}
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}
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}
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case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr:
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return func(yield func(Value) bool) {
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for i := range v.Uint() {
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if !yield(ValueOf(i)) {
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return
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}
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}
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}
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case Pointer:
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if v.Elem().kind() != Array {
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break
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}
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return func(yield func(Value) bool) {
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v = v.Elem()
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for i := range v.Len() {
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if !yield(ValueOf(i)) {
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return
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}
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}
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}
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case Array, Slice:
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return func(yield func(Value) bool) {
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for i := range v.Len() {
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if !yield(ValueOf(i)) {
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return
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}
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}
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}
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case String:
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return func(yield func(Value) bool) {
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for i := range v.String() {
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if !yield(ValueOf(i)) {
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return
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}
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}
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}
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case Map:
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return func(yield func(Value) bool) {
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i := v.MapRange()
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for i.Next() {
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if !yield(i.Key()) {
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return
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}
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}
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}
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case Chan:
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return func(yield func(Value) bool) {
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for value, ok := v.Recv(); ok; value, ok = v.Recv() {
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if !yield(value) {
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return
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}
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}
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}
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}
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panic("reflect: " + v.Type().String() + " cannot produce iter.Seq[Value]")
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}
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// Seq2 is like Seq but for two values.
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func (v Value) Seq2() iter.Seq2[Value, Value] {
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if canRangeFunc2(v.typ()) {
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return func(yield func(Value, Value) bool) {
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rf := MakeFunc(v.Type().In(0), func(in []Value) []Value {
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return []Value{ValueOf(yield(in[0], in[1]))}
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})
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v.Call([]Value{rf})
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}
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}
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switch v.Kind() {
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case Pointer:
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if v.Elem().kind() != Array {
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break
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}
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return func(yield func(Value, Value) bool) {
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v = v.Elem()
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for i := range v.Len() {
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if !yield(ValueOf(i), v.Index(i)) {
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return
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}
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}
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}
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case Array, Slice:
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return func(yield func(Value, Value) bool) {
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for i := range v.Len() {
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if !yield(ValueOf(i), v.Index(i)) {
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return
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}
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}
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}
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case String:
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return func(yield func(Value, Value) bool) {
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for i, v := range v.String() {
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if !yield(ValueOf(i), ValueOf(v)) {
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return
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}
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}
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}
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case Map:
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return func(yield func(Value, Value) bool) {
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i := v.MapRange()
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for i.Next() {
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if !yield(i.Key(), i.Value()) {
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return
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}
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}
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}
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}
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panic("reflect: " + v.Type().String() + " cannot produce iter.Seq2[Value, Value]")
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}
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280
src/reflect/iter_test.go
Normal file
280
src/reflect/iter_test.go
Normal file
@ -0,0 +1,280 @@
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// Copyright 2024 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package reflect_test
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import (
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"iter"
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"maps"
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. "reflect"
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"testing"
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)
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func TestValueSeq(t *testing.T) {
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m := map[string]int{
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"1": 1,
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"2": 2,
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"3": 3,
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"4": 4,
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}
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c := make(chan int, 3)
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for i := range 3 {
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c <- i
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}
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close(c)
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tests := []struct {
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name string
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val Value
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check func(*testing.T, iter.Seq[Value])
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}{
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{"int", ValueOf(4), func(t *testing.T, s iter.Seq[Value]) {
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i := int64(0)
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for v := range s {
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if v.Int() != i {
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t.Fatalf("got %d, want %d", v.Int(), i)
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}
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i++
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}
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if i != 4 {
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t.Fatalf("should loop four times")
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}
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}},
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{"uint", ValueOf(uint64(4)), func(t *testing.T, s iter.Seq[Value]) {
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i := uint64(0)
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for v := range s {
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if v.Uint() != i {
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t.Fatalf("got %d, want %d", v.Uint(), i)
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}
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i++
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}
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if i != 4 {
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t.Fatalf("should loop four times")
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}
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}},
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{"*[4]int", ValueOf(&[4]int{1, 2, 3, 4}), func(t *testing.T, s iter.Seq[Value]) {
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i := int64(0)
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for v := range s {
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if v.Int() != i {
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t.Fatalf("got %d, want %d", v.Int(), i)
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}
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i++
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}
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if i != 4 {
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t.Fatalf("should loop four times")
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}
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}},
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{"[4]int", ValueOf([4]int{1, 2, 3, 4}), func(t *testing.T, s iter.Seq[Value]) {
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i := int64(0)
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for v := range s {
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if v.Int() != i {
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t.Fatalf("got %d, want %d", v.Int(), i)
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}
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i++
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}
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if i != 4 {
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t.Fatalf("should loop four times")
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}
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}},
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{"[]int", ValueOf([]int{1, 2, 3, 4}), func(t *testing.T, s iter.Seq[Value]) {
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i := int64(0)
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for v := range s {
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if v.Int() != i {
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t.Fatalf("got %d, want %d", v.Int(), i)
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}
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i++
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}
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if i != 4 {
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t.Fatalf("should loop four times")
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}
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}},
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{"string", ValueOf("12语言"), func(t *testing.T, s iter.Seq[Value]) {
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i := int64(0)
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indexs := []int64{0, 1, 2, 5}
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for v := range s {
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if v.Int() != indexs[i] {
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t.Fatalf("got %d, want %d", v.Int(), indexs[i])
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}
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i++
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}
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if i != 4 {
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t.Fatalf("should loop four times")
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}
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}},
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{"map[string]int", ValueOf(m), func(t *testing.T, s iter.Seq[Value]) {
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i := int64(0)
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copy := maps.Clone(m)
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for v := range s {
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if _, ok := copy[v.String()]; !ok {
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t.Fatalf("unexpected %v", v.Interface())
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}
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delete(copy, v.String())
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i++
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}
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if len(copy) != 0 {
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t.Fatalf("should loop four times")
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}
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}},
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{"chan int", ValueOf(c), func(t *testing.T, s iter.Seq[Value]) {
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i := 0
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m := map[int64]bool{
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0: false,
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1: false,
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2: false,
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}
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for v := range s {
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if b, ok := m[v.Int()]; !ok || b {
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t.Fatalf("unexpected %v", v.Interface())
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}
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m[v.Int()] = true
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i++
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}
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if i != 3 {
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t.Fatalf("should loop three times")
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}
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}},
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{"func", ValueOf(func(yield func(int) bool) {
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for i := range 4 {
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if !yield(i) {
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return
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}
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}
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}), func(t *testing.T, s iter.Seq[Value]) {
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i := int64(0)
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for v := range s {
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if v.Int() != i {
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t.Fatalf("got %d, want %d", v.Int(), i)
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}
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i++
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}
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if i != 4 {
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t.Fatalf("should loop four times")
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}
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}},
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}
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for _, tc := range tests {
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seq := tc.val.Seq()
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tc.check(t, seq)
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}
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}
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func TestValueSeq2(t *testing.T) {
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m := map[string]int{
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"1": 1,
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"2": 2,
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"3": 3,
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"4": 4,
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}
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tests := []struct {
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name string
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val Value
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check func(*testing.T, iter.Seq2[Value, Value])
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}{
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{"*[4]int", ValueOf(&[4]int{1, 2, 3, 4}), func(t *testing.T, s iter.Seq2[Value, Value]) {
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i := int64(0)
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for v1, v2 := range s {
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if v1.Int() != i {
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t.Fatalf("got %d, want %d", v1.Int(), i)
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}
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i++
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if v2.Int() != i {
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t.Fatalf("got %d, want %d", v2.Int(), i)
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}
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}
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if i != 4 {
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t.Fatalf("should loop four times")
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}
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}},
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{"[4]int", ValueOf([4]int{1, 2, 3, 4}), func(t *testing.T, s iter.Seq2[Value, Value]) {
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i := int64(0)
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for v1, v2 := range s {
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if v1.Int() != i {
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t.Fatalf("got %d, want %d", v1.Int(), i)
|
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}
|
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i++
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if v2.Int() != i {
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t.Fatalf("got %d, want %d", v2.Int(), i)
|
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}
|
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}
|
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if i != 4 {
|
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t.Fatalf("should loop four times")
|
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}
|
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}},
|
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{"[]int", ValueOf([]int{1, 2, 3, 4}), func(t *testing.T, s iter.Seq2[Value, Value]) {
|
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i := int64(0)
|
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for v1, v2 := range s {
|
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if v1.Int() != i {
|
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t.Fatalf("got %d, want %d", v1.Int(), i)
|
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}
|
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i++
|
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if v2.Int() != i {
|
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t.Fatalf("got %d, want %d", v2.Int(), i)
|
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}
|
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}
|
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if i != 4 {
|
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t.Fatalf("should loop four times")
|
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}
|
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}},
|
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{"string", ValueOf("12语言"), func(t *testing.T, s iter.Seq2[Value, Value]) {
|
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i := int64(0)
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str := "12语言"
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next, stop := iter.Pull2(s)
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defer stop()
|
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for j, s := range str {
|
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v1, v2, ok := next()
|
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if !ok {
|
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t.Fatalf("should loop four times")
|
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}
|
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if v1.Int() != int64(j) {
|
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t.Fatalf("got %d, want %d", v1.Int(), j)
|
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}
|
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if v2.Interface() != s {
|
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t.Fatalf("got %v, want %v", v2.Interface(), s)
|
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}
|
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i++
|
||||
}
|
||||
if i != 4 {
|
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t.Fatalf("should loop four times")
|
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}
|
||||
}},
|
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{"map[string]int", ValueOf(m), func(t *testing.T, s iter.Seq2[Value, Value]) {
|
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copy := maps.Clone(m)
|
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for v1, v2 := range s {
|
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v, ok := copy[v1.String()]
|
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if !ok {
|
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t.Fatalf("unexpected %v", v1.String())
|
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}
|
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if v != v2.Interface() {
|
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t.Fatalf("got %v, want %d", v2.Interface(), v)
|
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}
|
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delete(copy, v1.String())
|
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}
|
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if len(copy) != 0 {
|
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t.Fatalf("should loop four times")
|
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}
|
||||
}},
|
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{"func", ValueOf(func(f func(int, int) bool) {
|
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for i := range 4 {
|
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f(i, i+1)
|
||||
}
|
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}), func(t *testing.T, s iter.Seq2[Value, Value]) {
|
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i := int64(0)
|
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for v1, v2 := range s {
|
||||
if v1.Int() != i {
|
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t.Fatalf("got %d, want %d", v1.Int(), i)
|
||||
}
|
||||
i++
|
||||
if v2.Int() != i {
|
||||
t.Fatalf("got %d, want %d", v2.Int(), i)
|
||||
}
|
||||
}
|
||||
if i != 4 {
|
||||
t.Fatalf("should loop four times")
|
||||
}
|
||||
}},
|
||||
}
|
||||
for _, tc := range tests {
|
||||
seq := tc.val.Seq2()
|
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tc.check(t, seq)
|
||||
}
|
||||
}
|
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@ -241,6 +241,12 @@ type Type interface {
|
||||
// It panics if t's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64.
|
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OverflowUint(x uint64) bool
|
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|
||||
// CanSeq reports whether a [Value] with this type can be iterated over using [Value.Seq].
|
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CanSeq() bool
|
||||
|
||||
// CanSeq2 reports whether a [Value] with this type can be iterated over using [Value.Seq2].
|
||||
CanSeq2() bool
|
||||
|
||||
common() *abi.Type
|
||||
uncommon() *uncommonType
|
||||
}
|
||||
@ -866,6 +872,62 @@ func (t *rtype) OverflowUint(x uint64) bool {
|
||||
panic("reflect: OverflowUint of non-uint type " + t.String())
|
||||
}
|
||||
|
||||
func (t *rtype) CanSeq() bool {
|
||||
switch t.Kind() {
|
||||
case Int8, Int16, Int32, Int64, Int, Uint8, Uint16, Uint32, Uint64, Uint, Uintptr, Array, Slice, Chan, String, Map:
|
||||
return true
|
||||
case Func:
|
||||
return canRangeFunc(&t.t)
|
||||
case Pointer:
|
||||
return t.Elem().Kind() == Array
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
func canRangeFunc(t *abi.Type) bool {
|
||||
if t.Kind() != abi.Func {
|
||||
return false
|
||||
}
|
||||
f := t.FuncType()
|
||||
if f.InCount != 1 || f.OutCount != 0 {
|
||||
return false
|
||||
}
|
||||
y := f.In(0)
|
||||
if y.Kind() != abi.Func {
|
||||
return false
|
||||
}
|
||||
yield := y.FuncType()
|
||||
return yield.InCount == 1 && yield.OutCount == 1 && yield.Out(0).Kind() == abi.Bool
|
||||
}
|
||||
|
||||
func (t *rtype) CanSeq2() bool {
|
||||
switch t.Kind() {
|
||||
case Array, Slice, String, Map:
|
||||
return true
|
||||
case Func:
|
||||
return canRangeFunc2(&t.t)
|
||||
case Pointer:
|
||||
return t.Elem().Kind() == Array
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
func canRangeFunc2(t *abi.Type) bool {
|
||||
if t.Kind() != abi.Func {
|
||||
return false
|
||||
}
|
||||
f := t.FuncType()
|
||||
if f.InCount != 1 || f.OutCount != 0 {
|
||||
return false
|
||||
}
|
||||
y := f.In(0)
|
||||
if y.Kind() != abi.Func {
|
||||
return false
|
||||
}
|
||||
yield := y.FuncType()
|
||||
return yield.InCount == 2 && yield.OutCount == 1 && yield.Out(0).Kind() == abi.Bool
|
||||
}
|
||||
|
||||
// add returns p+x.
|
||||
//
|
||||
// The whySafe string is ignored, so that the function still inlines
|
||||
|
||||
@ -117,3 +117,53 @@ func BenchmarkTypeForError(b *testing.B) {
|
||||
sinkType = reflect.TypeFor[error]()
|
||||
}
|
||||
}
|
||||
|
||||
func Test_Type_CanSeq(t *testing.T) {
|
||||
tests := []struct {
|
||||
name string
|
||||
tr reflect.Type
|
||||
want bool
|
||||
}{
|
||||
{"func(func(int) bool)", reflect.TypeOf(func(func(int) bool) {}), true},
|
||||
{"func(func(int))", reflect.TypeOf(func(func(int)) {}), false},
|
||||
{"int64", reflect.TypeOf(int64(1)), true},
|
||||
{"uint64", reflect.TypeOf(uint64(1)), true},
|
||||
{"*[4]int", reflect.TypeOf(&[4]int{}), true},
|
||||
{"chan int64", reflect.TypeOf(make(chan int64)), true},
|
||||
{"map[int]int", reflect.TypeOf(make(map[int]int)), true},
|
||||
{"string", reflect.TypeOf(""), true},
|
||||
{"[]int", reflect.TypeOf([]int{}), true},
|
||||
}
|
||||
for _, tt := range tests {
|
||||
t.Run(tt.name, func(t *testing.T) {
|
||||
if got := tt.tr.CanSeq(); got != tt.want {
|
||||
t.Errorf("Type.CanSeq() = %v, want %v", got, tt.want)
|
||||
}
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
func Test_Type_CanSeq2(t *testing.T) {
|
||||
tests := []struct {
|
||||
name string
|
||||
tr reflect.Type
|
||||
want bool
|
||||
}{
|
||||
{"func(func(int, int) bool)", reflect.TypeOf(func(func(int, int) bool) {}), true},
|
||||
{"func(func(int, int))", reflect.TypeOf(func(func(int, int)) {}), false},
|
||||
{"int64", reflect.TypeOf(int64(1)), false},
|
||||
{"uint64", reflect.TypeOf(uint64(1)), false},
|
||||
{"*[4]int", reflect.TypeOf(&[4]int{}), true},
|
||||
{"chan int64", reflect.TypeOf(make(chan int64)), false},
|
||||
{"map[int]int", reflect.TypeOf(make(map[int]int)), true},
|
||||
{"string", reflect.TypeOf(""), true},
|
||||
{"[]int", reflect.TypeOf([]int{}), true},
|
||||
}
|
||||
for _, tt := range tests {
|
||||
t.Run(tt.name, func(t *testing.T) {
|
||||
if got := tt.tr.CanSeq2(); got != tt.want {
|
||||
t.Errorf("Type.CanSeq2() = %v, want %v", got, tt.want)
|
||||
}
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user