add new Fill iterator

iters/valit/docs.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2022 individual contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// <https://www.apache.org/licenses/LICENSE-2.0>
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package valit allows for native Go values to be used with
+// iterators.
+//
+// Iterators:
+//   - Fill - yields the same value forever.
+package valit

iters/valit/fill.go

@@ -0,0 +1,30 @@
+// Copyright (c) 2022 individual contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// <https://www.apache.org/licenses/LICENSE-2.0>
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package valit
+
+import (
+	"github.com/0x5a17ed/itkit"
+)
+
+// FillIterator represents an iterator yielding the same value over and over again.
+type FillIterator[T any] struct{ v T }
+
+func (it FillIterator[T]) Value() T   { return it.v }
+func (it FillIterator[T]) Next() bool { return true }
+
+// Fill provides an iterator which yields the same value over and over again.
+func Fill[T any](v T) itkit.Iterator[T] {
+	return &FillIterator[T]{v: v}
+}

iters/valit/fill_test.go

@@ -0,0 +1,48 @@
+// Copyright (c) 2022 individual contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// <https://www.apache.org/licenses/LICENSE-2.0>
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package valit_test
+
+import (
+	"testing"
+
+	assertPkg "github.com/stretchr/testify/assert"
+	requirePkg "github.com/stretchr/testify/require"
+
+	"github.com/0x5a17ed/itkit/iters/valit"
+)
+
+func TestFillIterator(t *testing.T) {
+	type object struct{}
+
+	t.Run("integer", func(t *testing.T) {
+		iter := valit.Fill(10)
+
+		var got []int
+		for i := 0; i < 5; i += 1 {
+			requirePkg.True(t, iter.Next())
+			got = append(got, iter.Value())
+		}
+		assertPkg.Equal(t, []int{10, 10, 10, 10, 10}, got)
+	})
+
+	t.Run("struct", func(t *testing.T) {
+		var o object
+		iter := valit.Fill(&o)
+		for i := 0; i < 5; i += 1 {
+			requirePkg.True(t, iter.Next())
+			assertPkg.Same(t, &o, iter.Value())
+		}
+	})
+}