Add slicehelpers.Chunks

slicehelpers/slicehelpers.go

@@ -0,0 +1,23 @@
+package slicehelpers
+
+// Chunk splits the slice s into n number of chunks.
+func Chunk[T any](s []T, n int) [][]T {
+	if len(s) == 0 {
+		return nil
+	}
+	var partitions [][]T
+	sizeDefault := len(s) / n
+	sizeBig := len(s) - sizeDefault*n
+	size := sizeDefault + 1
+	for i, idx := 0, 0; i < n; i++ {
+		if i == sizeBig {
+			size--
+			if size == 0 {
+				break
+			}
+		}
+		partitions = append(partitions, s[idx:idx+size])
+		idx += size
+	}
+	return partitions
+}

slicehelpers/slicehelpers_test.go

@@ -0,0 +1,66 @@
+package slicehelpers
+
+import (
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+)
+
+func TestChunk(t *testing.T) {
+	c := qt.New(t)
+	c.Assert(Chunk(
+		[]int{1, 2, 3, 4, 5}, 2),
+		qt.DeepEquals,
+		[][]int{
+			{1, 2, 3},
+			{4, 5},
+		},
+	)
+
+	c.Assert(Chunk(
+		[]int{1, 2}, 3),
+		qt.DeepEquals,
+		[][]int{
+			{1},
+			{2},
+		},
+	)
+
+	c.Assert(Chunk(
+		[]int{1}, 2),
+		qt.DeepEquals,
+		[][]int{
+			{1},
+		},
+	)
+
+	c.Assert(Chunk(
+		[]int{}, 2),
+		qt.IsNil,
+	)
+
+	c.Assert(
+		Chunk([]string{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"}, 3),
+		qt.DeepEquals,
+		[][]string{
+			{"a", "b", "c", "d", "e", "f", "g", "h", "i"},
+			{"j", "k", "l", "m", "n", "o", "p", "q", "r"},
+			{"s", "t", "u", "v", "w", "x", "y", "z"},
+		},
+	)
+
+	c.Assert(
+		Chunk([]string{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"}, 7),
+		qt.DeepEquals,
+		[][]string{
+			{"a", "b", "c", "d"},
+			{"e", "f", "g", "h"},
+			{"i", "j", "k", "l"},
+			{"m", "n", "o", "p"},
+			{"q", "r", "s", "t"},
+			{"u", "v", "w"},
+			{"x", "y", "z"},
+		},
+	)
+
+}