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Subject: Re: [Caml-list] Simple idea for making a function infix
From: skaller <skaller@users.sourceforge.net>
To: Till Varoquaux <till.varoquaux@gmail.com>
Cc: Keisuke Nakano <ksk@mist.i.u-tokyo.ac.jp>, caml-list@inria.fr
In-Reply-To: <9d3ec8300611130819q7e13d5f4mb84b9fb1a2ac74ae@mail.gmail.com>
References: <1EB857FD-F706-419C-9181-D45DEA88B756@mist.i.u-tokyo.ac.jp>
	 <9d3ec8300611130819q7e13d5f4mb84b9fb1a2ac74ae@mail.gmail.com>
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Date: Tue, 14 Nov 2006 04:58:35 +1100
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X-Spam: no; 0.00; infix:01 0100,:01 redefining:01 sourceforge:01 wrote:01 precedence:01 caml-list:01 let:03 problem:05 fold:06 definition:07 approach:08 function:08 fun:08 john:09 

On Mon, 2006-11-13 at 17:19 +0100, Till Varoquaux wrote:
> Hi,
> 
> I don't really understand the point of the */ operator i your
> definition. It's fuy ecause I've cosiderig the same problem recetly ad
> came dow to this approach ( I'm redefining(@)... oe c )

> >    let ( /* ) x y = y x
> >    and ( */ ) x y = x y

The point is precedence: consider only /* then

	x /* f y

means

	x /* (f y)

whereas

	x /* f */ y

means

	(f x) y

Of course

	x /* f */ y z

means

	f x (y z)

but then 

	x + y z

also means

	(+) x (y z)


Also you can write

	x /* g h */ y

which means

	(g h) x y

which is kind of cute, eg:

	[] /* List.fold_left (fun x y -> y::x) */ [1;2;3]


-- 
John Skaller <skaller at users dot sf dot net>
Felix, successor to C++: http://felix.sf.net