@hackage foldl-transduce0.1.2.1

What's in this library?

Stateful transducers and streaming-preserving group operations for the folds in Gabriel Gonzalez's foldl package.

When to use this library?

• When you want to wrap a stateful decoder over a Fold. An example is decoding UTF-8: the decoder must be stateful because a multi-byte character may have been split across two blocks of bytes.

• When you want to tweak the stream of data that arrives into a Fold, but only at certain positions. Stripping whitespace at the beginning of a text stream, for example.

• When you want to perform group operations without breaking "streaminess", similar to what pipes-group does.

Why use this library for grouping instead of pipes-group?

Grouping fold-side instead of producer-side has the advantage that, since the results are still Folds, you can combine them using Applicative.

Also, Folds can work with sources other than Producers from pipes.

Grouping fold-side has limitations as well:

• You can't perform bracketing operations like "withFile" that span the folding of an entire group. You can do that in pipes-group.

• You have more flexibility in pipes-group to decide how to fold a group based on previous results.