underscore/scan.go
Ruidy 0bf04c224e
feat: add Scan function (reduce with history) (#43)
- Add Scan: returns all intermediate accumulator values
- Also known as prefix scan or cumulative fold
- Comprehensive tests including edge cases and different types
- Benchmark included

Example: Scan([]int{1,2,3,4}, 0, +) → [1, 3, 6, 10]

Resolves Issue 15

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <noreply@anthropic.com>
2025-11-16 08:53:05 +01:00

18 lines
466 B
Go

package underscore
// Scan is like Reduce but returns all intermediate accumulator values.
// Also known as prefix scan or cumulative fold.
//
// Example: Scan([]int{1,2,3,4}, 0, func(acc, n int) int { return acc + n }) → [1, 3, 6, 10]
func Scan[T, P any](values []T, acc P, fn func(P, T) P) []P {
if len(values) == 0 {
return []P{}
}
res := make([]P, 0, len(values))
for _, v := range values {
acc = fn(acc, v)
res = append(res, acc)
}
return res
}