slicehelpers: Add Partition

slicehelpers/slicehelpers.go

@@ -24,3 +24,22 @@ func Chunk[T any](s []T, n int) [][]T {
 	}
 	return partitions
 }
+
+// Parition partitions s into slices of size size.
+func Partition[T any](s []T, size int) [][]T {
+	if len(s) == 0 {
+		return nil
+	}
+	if size <= 0 {
+		return nil
+	}
+	var partitions [][]T
+	for i := 0; i < len(s); i += size {
+		end := i + size
+		if end > len(s) {
+			end = len(s)
+		}
+		partitions = append(partitions, s[i:end])
+	}
+	return partitions
+}

slicehelpers/slicehelpers_test.go

@@ -66,3 +66,72 @@ func TestChunk(t *testing.T) {
 		},
 	)
 }
+
+func TestPartition(t *testing.T) {
+	c := qt.New(t)
+
+	c.Assert(
+		Partition([]int{1, 2, 3, 4, 5}, 2),
+		qt.DeepEquals,
+		[][]int{
+			{1, 2},
+			{3, 4},
+			{5},
+		},
+	)
+
+	c.Assert(
+		Partition([]int{1, 2, 3, 4, 5}, 3),
+		qt.DeepEquals,
+		[][]int{
+			{1, 2, 3},
+			{4, 5},
+		},
+	)
+
+	c.Assert(
+		Partition([]int{1, 2, 3, 4, 5}, 1),
+		qt.DeepEquals,
+		[][]int{
+			{1},
+			{2},
+			{3},
+			{4},
+			{5},
+		},
+	)
+
+	c.Assert(
+		Partition([]int{1, 2, 3, 4, 5}, 5),
+		qt.DeepEquals,
+		[][]int{
+			{1, 2, 3, 4, 5},
+		},
+	)
+
+	c.Assert(
+		Partition([]int{1, 2, 3, 4, 5}, 6),
+		qt.DeepEquals,
+		[][]int{
+			{1, 2, 3, 4, 5},
+		},
+	)
+
+	c.Assert(
+		Partition([]int{1, 2, 3, 4, 5}, 7),
+		qt.DeepEquals,
+		[][]int{
+			{1, 2, 3, 4, 5},
+		},
+	)
+
+	c.Assert(
+		Partition([]int{1, 2, 3, 4, 5}, 0),
+		qt.IsNil,
+	)
+
+	c.Assert(
+		Partition([]int{}, 2),
+		qt.IsNil,
+	)
+}