On Fri, Mar 28, 2014 at 12:54:03AM -0500, John M. Dlugosz wrote:
More generally, is there some effective way to search for non-alphabetical Haskell things? Google just ignores the "punctuation".
You can find :| on Hayoo [1], the other handy place where to look for APIs stuff being Hoogle [2] (Hoogle is more focused on 'standard' Haskell libraries, Hayoo searches in all Hackage, both have their usefulness).
From there, if I need to search, say, a blog post, I will refer to the name of the typeclass/module/data and feed it to a search engine (so in this case "data NonEmpty etc. etc."). Apparently Google ignores punctuation in most cases [3].
Back to the original question
What is the meaning of :| ?
Clicking on the first occurrence in Hoogle brings me to Data.List.NonEmpty, where the specific operator is listed as the lone constructor of |data NonEmpty|. If the conspicuous name were not enough, checking the code: data NonEmpty a = a :| [a] we can see this looks like a list without the empty-list constructor. Does that answer your question? [1] http://holumbus.fh-wedel.de/hayoo/hayoo.html#0:%3A| [2] http://www.haskell.org/hoogle/ [3] https://support.google.com/websearch/answer/2466433 [4] http://hackage.haskell.org/package/semigroups-0.12.2/docs/Data-List-NonEmpty...