Golang proposal: iters: package with convenience methods for iter.Seq and iter.Seq2

Proposal Details

iter.Seq and iter.Seq2 open a wide range of possibilities to provide iterable views of data structures without involving memory copies.

While the Go standard library already provides some helper functions to create iter.Seq (e.g. slices.Values) or iter.Seq2 (e.g. maps.All), it still lacks many usual functions to manipulate the sequences (e.g. filtering, modifying) or aggregating them (e.g. Reduce, Max, Min).

I would like to offer the iters package to fill this gap: https://github.com/mariomac/iters , the donation would contain whole package, or just a part, depending on the Go community needs and criteria.

iters is a simple package relying only on the Go standard library that provides the following group of functionalities: * Instantiation of sequences (instantiate.go): creates sequences from slices, maps, varargs, numeric ranges, channels, and other sequences. It also allows generating infinite sequences from generator functions, or concatenating sequences. * Transformations of sequences (transformers.go): modify sequences (Map, Peek), filter them (Filter, Distinct), cut them (Limit, Skip)... * Aggregations of sequences (terminals.go): functional Reduce operator, common aggregators like Count, Max, Min, booleans (AllMatch, AnyMatch, NoneMatch), etc...

Some examples in the project README: https://github.com/mariomac/iters/blob/main/README.md

For more information about the provided functions, please go to the API documentation https://pkg.go.dev/github.com/mariomac/iters

Key points of the iters package: * Convenience methods for common operations, based on a well-known specification like the Java Streams API, for faster familiarization with developers. * Lazy evaluation allows working with infinite sequences without involving any copy of memory.

Comment From: apparentlymart

I think this earlier proposal overlaps this one: https://github.com/golang/go/issues/61898.

Comment From: mariomac

Thanks for the info @apparentlymart ! They totally overlap. Feel free to close te proposal if you think is not work repeating the same discussion again :)