[Haskell-cafe] Re: Re-order type (flip map)

Stephen Tetley stephen.tetley at gmail.com
Mon Oct 11 03:23:23 EDT 2010

On 11 October 2010 00:00, Johannes Waldmann
<waldmann at imn.htwk-leipzig.de> wrote:
>> My point was: you need to find/define two operators, not just one.
> Sure, I need  flip ($)  and  flip (.)
> Since the Prelude forgot to define these (and  flip map),
> the question was: are there established names for these two operators?

(#) was quite "established" for flip ($) around 2000 - its in a couple
of papers that appeared at the PADL conferences - one written by Erik
Meijer, Daan Leijen and (I think) James Hook on scripting Microsoft
Agents with COM. The authors noted reverse application with (#) gave
code a nice OO-like reading.

The other was Peter Thiemann's Wash - (#) is again flip ($) and (##)
is flipped compose.

Typographically I think these are a good fit, unfortunately they now
might play badly with GHC's magic hash operator.

Best wishes


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