slice_loop.go

package gofu

// MapChunks splits s into chunks, calls fn on each, and collects the results. [ Immutable ] [ time: O(n); space: O(n)]
//
// Chunks are distributed so the size difference between any two chunks is at most one element.
// See ForEachChunk for the exact distribution algorithm.
//
// Example:
//
//	gofu.Slice([]int{1, 2, 3, 4, 5, 6, 7}).
//	    MapChunks(3, func(i int, chunk gofu.Slice[int]) string { return fmt.Sprint(chunk) })
//	// []string{"[1 2 3]", "[4 5 6]", "[7]"}
func (s Slice[T]) MapChunks[R any](chunks int, fn func(int, Slice[T]) R) []R {
	if len(s) == 0 || chunks <= 1 {
		return []R{fn(0, s)}
	}
	if chunks > len(s) {
		chunks = len(s)
	}
	results := make([]R, chunks)
	size := len(s) / chunks
	rem := len(s) % chunks
	start := 0
	for i := 0; i < chunks; i++ {
		end := start + size
		if i < rem {
			end++
		}
		results[i] = fn(i, s[start:end])
		start = end
	}
	return results
}