Featured functions

We just started a new section of the site called “Featured functions” – This will house quick overviews of functions Though we may expand this beyond functions to also include featured types, typeclasses, libraries, etc. that we think deserve some extra love and attention.

We’ve opened it up with two list functions from the base package: Both of these functions also have variants in other packages, and so we also discuss ListLike, text, bytestring, containers, unordered-containers, vector, and witherable.

• mapMaybe – Map and filter a list at the same time! This is one that a lot of people look for but often miss because it’s tucked away at the bottom of the Data.Maybe module.
• intercalate – A mysterious word! We may not know how to pronounce it, but it comes in handy, usually when dealing with strings.

The Featured functions pages will all be free for everyone.

In the penultimate Web Servers lesson, we discuss connection persistence – why it is desirable, and how to make it happen. At this point, we are starting to really take full advantage of Attoparsec’s incremental parsing. We also begin to shift away from lazy I/O, preferring to explicitly read and write chunks of strict ByteStrings instead, in preparation for introducing pipes in the next lesson.