On 10/2/10, Christopher Done chrisd...@googlemail.com wrote:
On 2 October 2010 20:23, Max Bolingbroke batterseapo...@hotmail.com wrote:
Do you like this feature and think it would be worth incorporating
this into GHC? Or is it too specialised to be of use? If there is
enough support, I'll
To repeat, the analogues in SML and Erlang *do* support multiple
clauses (as well as pattern matching) and the failure of Haskell
lambdas to do so has always seemed like a weird restriction in a
language that's usually free of weird restrictions.
I agree with this sentiment. I have never
On 05/10/10 07:52, Nicolas Wu wrote:
I'd prefer to see something like
\ 1 - f
| 2 - g
but I'm sure something could be worked out.
While I think the case of
is a good idea, multiple clauses in lambdas seems more canonical to
me.
Alternatively, we could abandon
I also vote +1 for lambda-case, and abstain for lambda-if.
I don't think multiple-clause lambdas being desirable should be an
argument against lambda-case. After all, we can also define top-level
functions with either multiple clauses or a single case expression.
Haskell has always followed the
For what it's worth, after all this discussion my rather cheeky preference
is as follows:
Instead of introducing more specialised syntax, remove both existing special
syntaxes for if and case, and introduce multi-clause support for lambdas!
Cheers!
On 2 October 2010 19:23, Max Bolingbroke
Richard O'Keefe schrieb:
I'd prefer to see something like
\ 1 - f
| 2 - g
but I'm sure something could be worked out.
In order to be consistent with current case, maybe in layout mode:
\1 - f
2 - g
and in non-layout mode
\{1 - f; 2 - g}
?
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On 10/5/10 12:38 , Henning Thielemann wrote:
In order to be consistent with current case, maybe in layout mode:
\1 - f
2 - g
and in non-layout mode
\{1 - f; 2 - g}
+1; likewise for consistency it should support guards (which would
Donn Cave d...@avvanta.com writes:
I think you're not the first to ask. Just out of curiosity, or is
there a use for these variations?
Just that they seem to be natural generalizations. If it's just the
single form of paramtrizing the condition, I think it's better served by
a regular
Quoth Ketil Malde ke...@malde.org,
...
Just that they seem to be natural generalizations. If it's just the
single form of paramtrizing the condition, I think it's better served by
a regular function, 'bool' or (??) or whatever.
Well, yes, there's some logic to that. Like,
bool b c a = if a
On 5 October 2010 17:38, Henning Thielemann
schlepp...@henning-thielemann.de wrote:
Richard O'Keefe schrieb:
I'd prefer to see something like
\ 1 - f
| 2 - g
but I'm sure something could be worked out.
In order to be consistent with current case, maybe in layout mode:
\1 - f
On 4 October 2010 00:38, Conal Elliott co...@conal.net wrote:
I like it!
Are the other sections available as well, e.g.,
(if False then else Cafe) Haskell -- Cafe
They are not, though this would certainly make sense for lambda-if.
It's not so clear with lambda-case because of the issue
On 6/10/2010, at 5:56 AM, Brandon S Allbery KF8NH wrote:
In order to be consistent with current case, maybe in layout mode:
\1 - f
2 - g
and in non-layout mode
\{1 - f; 2 - g}
+1; likewise for consistency it should support guards (which would preclude
using | the way Richard
-1 for if then. The examples of curried if then else look, to my
eyes, less readable than the pointed version. And it's easy enough to
write a 'bool' deconstructor, or an 'ifM' for the monadic case.
+1 for something to solve the dummy - m; case dummy of problem.
Here are the possibilities I can
Max Bolingbroke batterseapo...@hotmail.com writes:
[1] http://hackage.haskell.org/trac/haskell-prime/ticket/41
I tried to find anything about lambda-if in there, but failed (Trac and
I aren't on very friendly terms, so it's probably my fault). Is there
more information about the rationale and
Quoth Ketil Malde ke...@malde.org,
Max Bolingbroke batterseapo...@hotmail.com writes:
...
Prelude (if then Haskell else Cafe) False
Cafe
Presumably, this extends to
Prelude (if False then else Cafe) Haskell
Cafe
and
Prelude (if then Haskell else) False Cafe
Cafe
as well?
I think
I really like the lambda-case. There are dozens of places in my code
where I could use it.
Not so sure about the lambda-if. It is just as easily done using an
ordinary function.
lambda-case: +1
lambda-if: neutral
___
Haskell-Cafe mailing list
On 4/10/2010, at 8:30 PM, Ketil Malde wrote:
Prelude (case of 1 - One; _ - Not-one) 1
One
Prelude :q
case of looks a bit weird, but I like the points brought up about
avoiding to name a one-use variable (e.g., getArgs = case of ...)
AFACS, this isn't easily implemented in Haskell
Quoth Richard O'Keefe o...@cs.otago.ac.nz,
...
Erlang manages fine with multiclause 'fun':
(fun (1) - One ; (_) - Not-one end)(1)
ML manages fine with multiclause 'fn':
(fn 1 = one | _ = not-one)(1)
In both cases, the same notation is used for multiclause lambda as
for single
On 5/10/2010, at 12:49 PM, Donn Cave wrote:
Just to be sure, are you saying, rather than
case of
1 - f
2 - g
you'd like to see \ support pattern matching etc. like named functions -
\ 1 - f
2 - g
Absolutely.For the record, lambda DOES support pattern
I like it!
Are the other sections available as well, e.g.,
(if False then else Cafe) Haskell -- Cafe
- Conal
On Sat, Oct 2, 2010 at 11:23 AM, Max Bolingbroke batterseapo...@hotmail.com
wrote:
Hi Cafe,
I implemented the proposed Haskell' feature lambda-case/lambda-if [1]
during the
Max == Max Bolingbroke batterseapo...@hotmail.com writes:
Prelude (if then Haskell else Cafe) False
Max Cafe
My reaction is to ask:
Can you write this as:
(if then else) False Haskell Cafe
?
--
Colin Adams
Preston Lancashire
() ascii ribbon campaign - against html e-mail
/\
On Sat, 2 Oct 2010, Max Bolingbroke wrote:
Hi Cafe,
I implemented the proposed Haskell' feature lambda-case/lambda-if [1]
during the Haskell Implementors Workshop yesterday for a bit of fun.
The patches are online [2, 3].
The feature is demonstrated in this GHCi session:
$
On Sat, 2 Oct 2010, Colin Paul Adams wrote:
Max == Max Bolingbroke batterseapo...@hotmail.com writes:
Prelude (if then Haskell else Cafe) False
Max Cafe
My reaction is to ask:
Can you write this as:
(if then else) False Haskell Cafe
?
Sure:
ifThenElse :: Bool - a - a - a
On 2 October 2010 20:23, Max Bolingbroke batterseapo...@hotmail.com wrote:
Do you like this feature and think it would be worth incorporating
this into GHC? Or is it too specialised to be of use? If there is
enough support, I'll create a ticket and see what GHC HQ make of it.
Nice work! I like
I just had a look at hpaste.org, and, amusingly, the first paste has this:
down - openLazyURI http://list.iblocklist.com/?list=bt_level1;
case down of
Left _ - error Could not download file
Right bs - do input - bs
...
I can
On 2 October 2010 19:33, Henning Thielemann
lemm...@henning-thielemann.dewrote:
On Sat, 2 Oct 2010, Max Bolingbroke wrote:
... lambda-case/lambda-if ...
Nice! Concerning if-then-else I would more like to see an according
function to go to Data.Bool, then we won't need more syntactic sugar
On 02.10.2010, at 20:35, Henning Thielemann wrote:
On Sat, 2 Oct 2010, Colin Paul Adams wrote:
Prelude (if then Haskell else Cafe) False
Max Cafe
My reaction is to ask:
Can you write this as:
(if then else) False Haskell Cafe
?
Sure:
ifThenElse :: Bool - a - a - a
ifThenElse
On Sat, Oct 2, 2010 at 4:13 PM, Christopher Done
chrisd...@googlemail.com wrote:
There's nothing more annoying than having to introduce intermediate
bindings when you're going to immediate pattern match against it
immediately and never use it again. It's both annoying to have to
think of a
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On 10/2/10 15:27 , Jan Christiansen wrote:
You can use a similar approach for case expressions ; )
There are several better (that is, not using unsafePerformIO) versions at
http://haskell.org/haskellwiki/Case .
- --
brandon s. allbery
On 10/2/10 3:13 PM, Christopher Done wrote:
There's nothing more annoying than having to introduce intermediate
bindings when you're going to immediate pattern match against it
immediately and never use it again. It's both annoying to have to
think of a variable name that makes sense and is not
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