All

Executes a function for each item in a slice concurrently. Uses a Group internally.

Signature

func All[T any](ctx context.Context, items []T, fn func(ctx context.Context, item T) error, opts ...GroupOption) error

Type Parameters

Parameter	Description
T	The type of each item in the slice.

Parameters

Parameter	Type	Description
ctx	context.Context	Parent context.
items	[]T	Slice of items to iterate over.
fn	func(ctx context.Context, item T) error	Function to execute for each item.
opts	...GroupOption	Options passed to the underlying NewGroup call.

Return Value

Returns nil if all invocations succeed. Otherwise returns all errors via errors.Join.

If items is empty, returns nil immediately without creating a group.

Options

Naming

Option	Description
WithName(name)	Custom metric/tracing label. Default: "gofuncy.all"

Resilience

Option	Description
WithTimeout(d)	Per-invocation timeout. Each retry attempt gets a fresh deadline.
WithRetry(n, opts...)	Automatic retry with configurable backoff.
WithCircuitBreaker(cb)	Fail fast on broken dependencies. Stateful — share across calls.
WithFallback(fn, opts...)	Called when the operation fails. Return nil to suppress the error.

Telemetry

Option	Default	Description
WithoutTracing()	on	Disable span creation.
WithDetachedTrace()	varies	Root span linked to parent instead of child span. Default for Go/Start/StartWithReady/StartWithStop/GoWithCancel.
WithChildTrace()	varies	Force child span. Default for Do/Wait/NewGroup.
WithoutStartedCounter()	on	Disable started counter.
WithoutErrorCounter()	on	Disable error counter.
WithoutActiveUpDownCounter()	on	Disable active counter.
WithDurationHistogram()	off	Enable duration histogram.
WithMeterProvider(mp)	global	Custom OTel meter provider.
WithTracerProvider(tp)	global	Custom OTel tracer provider.

Concurrency

Option	Description
WithLimiter(sem)	Shared *semaphore.Weighted for cross-callsite concurrency control.

Middleware

Option	Description
WithMiddleware(m...)	Append custom middleware. Applied after resilience, before telemetry.
WithLogger(l)	Custom *slog.Logger for error reporting.
WithStallThreshold(d)	Log a warning if the goroutine runs longer than d.
WithStallHandler(h)	Custom callback for stall detection.

Group-Only

Option	Description
WithLimit(n)	Max concurrent functions in this group.
WithFailFast()	Cancel remaining functions on first error.

Example

package main

import (
	"context"
	"fmt"

	"github.com/foomo/gofuncy"
)

func main() {
	ctx := context.Background()

	urls := []string{
		"https://api.example.com/users",
		"https://api.example.com/orders",
		"https://api.example.com/products",
	}

	err := gofuncy.All(ctx, urls, func(ctx context.Context, url string) error {
		fmt.Println("fetching", url)
		// fetch(ctx, url)
		return nil
	},
		gofuncy.WithLimit(2), // at most 2 concurrent fetches
	)
	if err != nil {
		fmt.Println("errors:", err)
	}
}

TIP

All is a convenience wrapper around NewGroup + Add + Wait. If you need per-item options or want to add functions dynamically, use Group directly.