Support Go 1.22 and 1.23

.github/workflows/test.yaml

@@ -19,7 +19,7 @@ jobs:
         env: { GOEXPERIMENT: rangefunc }
       - uses: codecov/codecov-action@v4
         env: { CODECOV_TOKEN: "${{ secrets.CODECOV_TOKEN }}" }
-  test:
+  test-123:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
@@ -31,3 +31,16 @@ jobs:
           go-version: 1.23.0-rc.1
           cache: false
       - run: make test
+  test-122:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.22"
+          cache: false
+      - run: make test
+        env: { GOEXPERIMENT: rangefunc }

future/maps/maps.go

@@ -1,29 +1,22 @@
+//go:build go1.23
+
 // Package maps provides early implementations of map-related functions
 // available in Go 1.23+.
 package maps
 
-import "iter"
+import (
+	"iter"
+	"maps"
+)
 
 // All returns an iterator over key-value pairs from m. The iteration order is
 // not specified and is not guaranteed to be the same from one call to the
 // next.
 func All[Map ~map[K]V, K comparable, V any](m Map) iter.Seq2[K, V] {
-	return func(yield func(K, V) bool) {
-		for key, value := range m {
-			if !yield(key, value) {
-				return
-			}
-		}
-	}
+	return maps.All(m)
 }
 
 // Collect collects key-value pairs from seq into a new map and returns it.
 func Collect[K comparable, V any](seq iter.Seq2[K, V]) map[K]V {
-	m := make(map[K]V)
-
-	for key, value := range seq {
-		m[key] = value
-	}
-
-	return m
+	return maps.Collect(seq)
 }

future/maps/maps_1.22.go

@@ -0,0 +1,37 @@
+//go:build go1.22 && rangefunc
+
+// Package maps provides early implementations of map-related functions
+// available in Go 1.23+.
+//
+// If using Go 1.22, the rangefunc experimental feature must be enabled.
+//
+// If using Go 1.23 or later, prefer the functions from the standard library.
+//
+// This package will be removed in Go 1.24.
+package maps
+
+import "iter"
+
+// All returns an iterator over key-value pairs from m. The iteration order is
+// not specified and is not guaranteed to be the same from one call to the
+// next.
+func All[Map ~map[K]V, K comparable, V any](m Map) iter.Seq2[K, V] {
+	return func(yield func(K, V) bool) {
+		for key, value := range m {
+			if !yield(key, value) {
+				return
+			}
+		}
+	}
+}
+
+// Collect collects key-value pairs from seq into a new map and returns it.
+func Collect[K comparable, V any](seq iter.Seq2[K, V]) map[K]V {
+	m := make(map[K]V)
+
+	for key, value := range seq {
+		m[key] = value
+	}
+
+	return m
+}

future/slices/slices.go

@@ -1,27 +1,18 @@
-// Package slices provides early implementations of slice-related functions
-// available in Go 1.23+.
+//go:build go1.23
+
 package slices
 
-import "iter"
+import (
+	"iter"
+	"slices"
+)
 
 // Values returns an iterator over the slice elements, starting with s[0].
 func Values[Slice ~[]E, E any](slice Slice) iter.Seq[E] {
-	return func(yield func(E) bool) {
-		for _, value := range slice {
-			if !yield(value) {
-				return
-			}
-		}
-	}
+	return slices.Values(slice)
 }
 
 // Collect collects values from seq into a new slice and returns it.
 func Collect[E any](seq iter.Seq[E]) []E {
-	slice := make([]E, 0)
-
-	for item := range seq {
-		slice = append(slice, item)
-	}
-
-	return slice
+	return slices.Collect(seq)
 }

future/slices/slices_1.22.go

@@ -0,0 +1,35 @@
+//go:build go1.22 && rangefunc
+
+// Package slices provides early implementations of slice-related functions
+// available in Go 1.23+.
+//
+// If using Go 1.22, the rangefunc experimental feature must be enabled.
+//
+// If using Go 1.23 or later, prefer the functions from the standard library.
+//
+// This package will be removed in Go 1.24.
+package slices
+
+import "iter"
+
+// Values returns an iterator over the slice elements, starting with s[0].
+func Values[Slice ~[]E, E any](slice Slice) iter.Seq[E] {
+	return func(yield func(E) bool) {
+		for _, value := range slice {
+			if !yield(value) {
+				return
+			}
+		}
+	}
+}
+
+// Collect collects values from seq into a new slice and returns it.
+func Collect[E any](seq iter.Seq[E]) []E {
+	slice := make([]E, 0)
+
+	for item := range seq {
+		slice = append(slice, item)
+	}
+
+	return slice
+}