[Haskell-cafe] Re: map (-2) [1..5]

[Jón Fairbairn]

Aaron Denney <wnoise at ofb.net> writes:

> We already have this great syntax, parsing semanticsi for precedence,
> and so forth for declaring infix operators.  Couldn't we add to that
> slightly by declaring postfix operators as well?  Actually, declaring a
> unary operator infix yielding a postfix operator doesn't seem like too
> much abuse. 

Possibly not, provided they're always used as sections. 
(e #) already always means "supply e as the first argument
to (#)").

> (I haven't thought this through to any great extent.  How much would it
> complicate parsing?  Not much, I would assume, as this fails in ghc at
> the type-checking stage.)

I don't think it would complicate mechanical parsing
unreasonably. I do think (if done without the parentheses)
it might complicate /human/ parsing unreasonably.

-- 
Jón Fairbairn                                 Jon.Fairbairn at cl.cam.ac.uk
http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html  (updated 2006-09-07)