[Haskell-cafe] Arrows: definition of pure & arr

Wolfgang Jeltsch g9ks157k at acme.softbase.org
Tue Feb 19 05:28:40 EST 2008

Am Sonntag, 17. Februar 2008 14:32 schrieb Peter Verswyvelen:
> I don't get why the name isn't "arrow" instead of "arr"... Arr reminds
> me of pirates, "arrrrrrrhh" ;-)
> I guess "first" was chosen because "fst" was already taken, but then it
> would be logical to choose "arrow" instead of "arr" ;-)

arr has two problems in my opinion.  First, it is an unneccessarily truncated 
name.  Is it really so difficult to type two letters more?  Second, it 
doesn’t describe its purpose very well.  Okay, it constructs an arrow.  But 
(>>>) and first do this as well.  pure makes much more sense to me, since it 
says that it constructs *pure* arrows.

If you look at Grapfruit’s source code, you probably won’t find any occurences 
of arr (but you’ll find Arrow.pure rather often).

Best wishes,

More information about the Haskell-Cafe mailing list