There is no technical reason for this. It's a matter of taste. As someone
else pointed out, different arities is usually a bug.
-- Lennart
On Jan 13, 2008 3:12 PM, Neil Mitchell [EMAIL PROTECTED] wrote:
Hi,
It's nice to write functions in point free style:
f = sort . nub
But
Hello Neil,
Monday, January 14, 2008, 2:12:52 AM, you wrote:
But sometimes I have to add an extra case, on a certain value:
f [] = [1]
f = sort . nub
Is there a reason this isn't done?
this may be also due an error, and in most cases it actually will be
due an error. then it makes type
That eta-expansion desugaring would lose sharing. Offhand, I don't know of
a desugaring that would do the trick and preserve sharing. Any ideas? -
Conal
On Jan 13, 2008 3:12 PM, Neil Mitchell [EMAIL PROTECTED] wrote:
Hi,
It's nice to write functions in point free style:
f = sort . nub
G'day all.
Quoting Neil Mitchell [EMAIL PROTECTED]:
It's nice to write functions in point free style:
f = sort . nub
But sometimes I have to add an extra case, on a certain value:
f [] = [1]
f = sort . nub
But now these equations have different arities, and its rejected by
Haskell.
I
G'day all.
Quoting Conal Elliott [EMAIL PROTECTED]:
That eta-expansion desugaring would lose sharing. Offhand, I don't know of
a desugaring that would do the trick and preserve sharing. Any ideas?
How about this?
f = let body = sort . nub
in \xs - case xs of
[] - [1]
Hi Conal,
On 1/13/08, Conal Elliott [EMAIL PROTECTED] wrote:
That eta-expansion desugaring would lose sharing.
Ah, that will be it.
1. Equations with different arities more often signal bugs than
correct intentions.
I don't believe that. I suspect the type system will mop these up.
2.
Neil Mitchell writes:
I quite like the idea of permitting equations to have different
arities. It removes restrictions, makes things more regular etc.
More regular???
My goodness... Of course, it removes restrictions. But in the history of
humanity rarely the removal of restrictions made
On 13 Jan 2008, at 5:38 PM, [EMAIL PROTECTED] wrote:
Neil Mitchell writes:
I quite like the idea of permitting equations to have different
arities. It removes restrictions, makes things more regular etc.
More regular???
My goodness... Of course, it removes restrictions. But in the
history
Neil Mitchell wrote:
Hi,
It's nice to write functions in point free style:
f = sort . nub
But sometimes I have to add an extra case, on a certain value:
f [] = [1]
f = sort . nub
But now these equations have different arities, and its rejected by
Haskell. Why does this not simply desugar
G'day all.
Quoting Neil Mitchell [EMAIL PROTECTED]:
I don't believe that. I suspect the type system will mop these up.
As previously noted, anything involving undefined (thanks to seq) is
not equivalent.
While undefined is arguably uncommon, error most certainly isn't:
f1 (x:xs) = {-
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