mirror of
https://github.com/rjNemo/underscore
synced 2026-06-06 10:36:43 +00:00
Ruidy
1031038d42
- Add `Chunk` to split slices into groups of size n. - Add `ContainsBy` for predicate-based containment checks. - Add `UniqueBy` to deduplicate slices by key selector. - Add `ParallelMap` for concurrent mapping with context and error handling. - Add `maps.Keys` and `maps.Values` helpers for extracting map keys/values. - Update README and docs for new features. - Refactor `Contains` to use `slices.Contains`.
72 lines
1.2 KiB
Go
72 lines
1.2 KiB
Go
package underscore
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import (
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"context"
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"runtime"
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"sync"
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)
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// ParallelMap applies fn to each element of values using a worker pool and preserves order.
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// If workers <= 0, it defaults to GOMAXPROCS.
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// On error, the first error is returned and processing is canceled; partial results are discarded.
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func ParallelMap[T, P any](ctx context.Context, values []T, workers int, fn func(context.Context, T) (P, error)) ([]P, error) {
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if workers <= 0 {
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workers = runtime.GOMAXPROCS(0)
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}
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type task struct {
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idx int
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val T
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}
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res := make([]P, len(values))
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tasks := make(chan task)
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ctx, cancel := context.WithCancel(ctx)
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defer cancel()
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var wg sync.WaitGroup
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var once sync.Once
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var firstErr error
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worker := func() {
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defer wg.Done()
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for t := range tasks {
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select {
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case <-ctx.Done():
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return
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default:
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}
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v, err := fn(ctx, t.val)
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if err != nil {
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once.Do(func() {
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firstErr = err
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cancel()
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})
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continue
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}
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res[t.idx] = v
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}
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}
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wg.Add(workers)
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for i := 0; i < workers; i++ {
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go worker()
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}
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OUTER:
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for i, v := range values {
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select {
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case <-ctx.Done():
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break OUTER
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default:
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tasks <- task{idx: i, val: v}
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}
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}
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close(tasks)
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wg.Wait()
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if firstErr != nil {
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return nil, firstErr
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}
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return res, nil
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}
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