Generalize BreakUp/RangByChunks functions

utils/slice/slice.go

@@ -54,3 +54,28 @@ func Move[T any](slice []T, srcIndex int, dstIndex int) []T {
 	value := slice[srcIndex]
 	return Insert(Remove(slice, srcIndex), value, dstIndex)
 }
+
+func BreakUp[T any](items []T, chunkSize int) [][]T {
+	numTracks := len(items)
+	var chunks [][]T
+	for i := 0; i < numTracks; i += chunkSize {
+		end := i + chunkSize
+		if end > numTracks {
+			end = numTracks
+		}
+
+		chunks = append(chunks, items[i:end])
+	}
+	return chunks
+}
+
+func RangeByChunks[T any](items []T, chunkSize int, cb func([]T) error) error {
+	chunks := BreakUp(items, chunkSize)
+	for _, chunk := range chunks {
+		err := cb(chunk)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

utils/slice/slice_test.go

@@ -69,4 +69,25 @@ var _ = Describe("Slice Utils", func() {
 			Expect(slice.Move([]string{"1", "2", "3"}, 1, 1)).To(ConsistOf("1", "2", "3"))
 		})
 	})
+
+	Describe("BreakUp", func() {
+		It("returns no chunks if slice is empty", func() {
+			var s []string
+			chunks := slice.BreakUp(s, 10)
+			Expect(chunks).To(HaveLen(0))
+		})
+		It("returns the slice in one chunk if len < chunkSize", func() {
+			s := []string{"a", "b", "c"}
+			chunks := slice.BreakUp(s, 10)
+			Expect(chunks).To(HaveLen(1))
+			Expect(chunks[0]).To(ConsistOf("a", "b", "c"))
+		})
+		It("breaks up the slice if len > chunkSize", func() {
+			s := []string{"a", "b", "c", "d", "e"}
+			chunks := slice.BreakUp(s, 3)
+			Expect(chunks).To(HaveLen(2))
+			Expect(chunks[0]).To(ConsistOf("a", "b", "c"))
+			Expect(chunks[1]).To(ConsistOf("d", "e"))
+		})
+	})
 })