[release-branch.go1.21] maps: remove Keys and Values

Preserve the names in case we want them to return an iterator.
Keep the efficient runtime implementations for now,
as we will probably want them under some name, perhaps KeysSlice
and ValuesSlice.

Fixes golang#61538

Change-Id: I6b03010bf071fb4531cb2f967dad46425962fcb8
Reviewed-on: https://go-review.googlesource.com/c/go/+/513476
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-on: https://go-review.googlesource.com/c/go/+/513715
Run-TryBot: Russ Cox <rsc@golang.org>

api/go1.21.txt

@@ -344,8 +344,6 @@ pkg maps, func Copy[$0 interface{ ~map[$2]$3 }, $1 interface{ ~map[$2]$3 }, $2 c
 pkg maps, func DeleteFunc[$0 interface{ ~map[$1]$2 }, $1 comparable, $2 interface{}]($0, func($1, $2) bool) #57436
 pkg maps, func Equal[$0 interface{ ~map[$2]$3 }, $1 interface{ ~map[$2]$3 }, $2 comparable, $3 comparable]($0, $1) bool #57436
 pkg maps, func EqualFunc[$0 interface{ ~map[$2]$3 }, $1 interface{ ~map[$2]$4 }, $2 comparable, $3 interface{}, $4 interface{}]($0, $1, func($3, $4) bool) bool #57436
-pkg maps, func Keys[$0 interface{ ~map[$1]$2 }, $1 comparable, $2 interface{}]($0) []$1 #57436
-pkg maps, func Values[$0 interface{ ~map[$1]$2 }, $1 comparable, $2 interface{}]($0) []$2 #57436
 pkg math/big, method (*Int) Float64() (float64, Accuracy) #56984
 pkg net/http, method (*ProtocolError) Is(error) bool #41198
 pkg net/http, method (*ResponseController) EnableFullDuplex() error #57786

src/maps/maps.go

@@ -5,34 +5,6 @@
 // Package maps defines various functions useful with maps of any type.
 package maps
 
-import "unsafe"
-
-// keys is implemented in the runtime package.
-//
-//go:noescape
-func keys(m any, slice unsafe.Pointer)
-
-// Keys returns the keys of the map m.
-// The keys will be in an indeterminate order.
-func Keys[M ~map[K]V, K comparable, V any](m M) []K {
-	r := make([]K, 0, len(m))
-	keys(m, unsafe.Pointer(&r))
-	return r
-}
-
-// values is implemented in the runtime package.
-//
-//go:noescape
-func values(m any, slice unsafe.Pointer)
-
-// Values returns the values of the map m.
-// The values will be in an indeterminate order.
-func Values[M ~map[K]V, K comparable, V any](m M) []V {
-	r := make([]V, 0, len(m))
-	values(m, unsafe.Pointer(&r))
-	return r
-}
-
 // Equal reports whether two maps contain the same key/value pairs.
 // Values are compared using ==.
 func Equal[M1, M2 ~map[K]V, K, V comparable](m1 M1, m2 M2) bool {

src/maps/maps_test.go

@@ -6,87 +6,13 @@ package maps
 
 import (
 	"math"
-	"slices"
-	"sort"
 	"strconv"
 	"testing"
-	"unsafe"
 )
 
 var m1 = map[int]int{1: 2, 2: 4, 4: 8, 8: 16}
 var m2 = map[int]string{1: "2", 2: "4", 4: "8", 8: "16"}
 
-func keysForBenchmarking[M ~map[K]V, K comparable, V any](m M, s []K) {
-	keys(m, unsafe.Pointer(&s))
-}
-
-func TestKeys(t *testing.T) {
-	want := []int{1, 2, 4, 8}
-
-	got1 := Keys(m1)
-	sort.Ints(got1)
-	if !slices.Equal(got1, want) {
-		t.Errorf("Keys(%v) = %v, want %v", m1, got1, want)
-	}
-
-	got2 := Keys(m2)
-	sort.Ints(got2)
-	if !slices.Equal(got2, want) {
-		t.Errorf("Keys(%v) = %v, want %v", m2, got2, want)
-	}
-
-	// test for oldbucket code path
-	// We grow from 128 to 256 buckets at size 832 (6.5 * 128).
-	// Then we have to evacuate 128 buckets, which means we'll be done evacuation at 832+128=960 elements inserted.
-	// so 840 is a good number to test for oldbucket code path.
-	var want3 []int
-	var m = make(map[int]int)
-	for i := 0; i < 840; i++ {
-		want3 = append(want3, i)
-		m[i] = i * i
-	}
-
-	got3 := Keys(m)
-	sort.Ints(got3)
-	if !slices.Equal(got3, want3) {
-		t.Errorf("Keys(%v) = %v, want %v", m, got3, want3)
-	}
-}
-
-func valuesForBenchmarking[M ~map[K]V, K comparable, V any](m M, s []V) {
-	values(m, unsafe.Pointer(&s))
-}
-
-func TestValues(t *testing.T) {
-	got1 := Values(m1)
-	want1 := []int{2, 4, 8, 16}
-	sort.Ints(got1)
-	if !slices.Equal(got1, want1) {
-		t.Errorf("Values(%v) = %v, want %v", m1, got1, want1)
-	}
-
-	got2 := Values(m2)
-	want2 := []string{"16", "2", "4", "8"}
-	sort.Strings(got2)
-	if !slices.Equal(got2, want2) {
-		t.Errorf("Values(%v) = %v, want %v", m2, got2, want2)
-	}
-
-	//test for oldbucket code path
-	var want3 []int
-	var m = make(map[int]int)
-	for i := 0; i < 840; i++ {
-		want3 = append(want3, i*i)
-		m[i] = i * i
-	}
-
-	got3 := Values(m)
-	sort.Ints(got3)
-	if !slices.Equal(got3, want3) {
-		t.Errorf("Values(%v) = %v, want %v", m, got3, want3)
-	}
-}
-
 func TestEqual(t *testing.T) {
 	if !Equal(m1, m1) {
 		t.Errorf("Equal(%v, %v) = false, want true", m1, m1)
@@ -256,29 +182,3 @@ func TestCloneWithMapAssign(t *testing.T) {
 		}
 	}
 }
-
-func BenchmarkKeys(b *testing.B) {
-	m := make(map[int]int, 1000000)
-	for i := 0; i < 1000000; i++ {
-		m[i] = i
-	}
-	b.ResetTimer()
-
-	slice := make([]int, 0, len(m))
-	for i := 0; i < b.N; i++ {
-		keysForBenchmarking(m, slice)
-	}
-}
-
-func BenchmarkValues(b *testing.B) {
-	m := make(map[int]int, 1000000)
-	for i := 0; i < 1000000; i++ {
-		m[i] = i
-	}
-	b.ResetTimer()
-
-	slice := make([]int, 0, len(m))
-	for i := 0; i < b.N; i++ {
-		valuesForBenchmarking(m, slice)
-	}
-}