This repository provides Go concurrency utils to execute tasks and collect results or errors concurrently.

gruppen.Gather and gruppen.GatherSoon use errgroup.Group to control and limit concurrency, the results are collected to a []interface{}. If any non-nil error occurs, the first one would be returned.

When a non-nil error is found, gruppen.GatherSoon uses an additional channel to cancel all the tasks not started; while gruppen.Gather continues to execute the remaining tasks with the cancel func for the ctx called.

gruppen comes from the name of a well-known 20-th century composition for three orchestras by Karlheinz Stockhausen.

facebookgo/errgroup is similar to sync.WaitGroup, but it collects all the errors.

gollback and hunch provide functions as gruppen.Gather does, but the concurrency cannot be set directly.