Support 1.23 iterator for set (#140)

* ci: add 1.22 and 1.23.0-rc2 and upgrade action version

* Add Values function return 1.23 iterator

* ci: add go versions in ci to 1.23.x and 1.24.x

* Rename Values to Elements

Use the name "Element" as it is more intuitive.

Author: amikai

.github/workflows/ci.yml

@@ -4,19 +4,18 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.20.1, 1.21.1]
+        go-version: [1.20.x, 1.21.x, 1.22.x, 1.23.x, 1.24.x]
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
-    - name: Install Go
-      uses: actions/setup-go@v3
-      with:
-        go-version: ${{ matrix.go-version }}
-        stable: false
-    - name: Checkout code
-      uses: actions/checkout@v3
-    - name: Test
-      run: |
-        go test -v -race ./...
-        # go vet ./...
-        # go test -bench=.
+      - name: Install Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ matrix.go-version }}
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Test
+        run: |
+          go test -v -race ./...
+          # go vet ./...
+          # go test -bench=.

set.go

@@ -257,3 +257,13 @@ func NewThreadUnsafeSetFromMapKeys[T comparable, V any](val map[T]V) Set[T] {
 
 	return s
 }
+
+// Elements returns an iterator that yields the elements of the set. Starting
+// with Go 1.23, users can use a for loop to iterate over it.
+func Elements[T comparable](s Set[T]) func(func(element T) bool) {
+	return func(yield func(element T) bool) {
+		s.Each(func(t T) bool {
+			return !yield(t)
+		})
+	}
+}

set123_test.go

@@ -0,0 +1,38 @@
+//go:build go1.23
+// +build go1.23
+
+package mapset
+
+import (
+	"testing"
+)
+
+func Test_Elements123(t *testing.T) {
+	a := NewSet[string]()
+
+	a.Add("Z")
+	a.Add("Y")
+	a.Add("X")
+	a.Add("W")
+
+	b := NewSet[string]()
+	for elem := range Elements(a) {
+		b.Add(elem)
+	}
+
+	if !a.Equal(b) {
+		t.Error("The sets are not equal after iterating (Each) through the first set")
+	}
+
+	var count int
+	for range Elements(a) {
+		if count == 2 {
+			break
+		}
+		count++
+	}
+
+	if count != 2 {
+		t.Error("Iteration should stop on the way")
+	}
+}

set_test.go

@@ -1373,6 +1373,38 @@ func Test_NewThreadUnsafeSetFromMapKey_Strings(t *testing.T) {
 	}
 }
 
+func Test_Elements(t *testing.T) {
+	a := NewSet[string]()
+
+	a.Add("Z")
+	a.Add("Y")
+	a.Add("X")
+	a.Add("W")
+
+	b := NewSet[string]()
+	Elements(a)(func(elem string) bool {
+		b.Add(elem)
+		return true
+	})
+
+	if !a.Equal(b) {
+		t.Error("The sets are not equal after iterating (Each) through the first set")
+	}
+
+	var count int
+	Elements(a)(func(elem string) bool {
+		if count == 2 {
+			return false
+		}
+		count++
+		return true
+	})
+
+	if count != 2 {
+		t.Error("Iteration should stop on the way")
+	}
+}
+
 func Test_Example(t *testing.T) {
 	/*
 	   requiredClasses := NewSet()