Concurrency pattern: worker with variable number of results

I want to create a worker pool in golang, to divide a big task in multiple jobs.

The problem is that the routines may produce multiple output as a result for the computation, so I cannot know in advance how many times I shall iterate over the results channel.

I know that I can use WaitGroup, but I was wondering if there is another pattern I can use, in order to let the main thread advanced on the computation and iterate over the results instead of waiting first every routine to be done.

Another solution I thought, which is not very elegant to me, is to create a Result struct or return an array of results. Since I can count the number of works, I know how many results arrays I'm gonna receive.