[I think this thread would be more appropriate on haskell-café, so I'm redirecting it]
| addToSPair :: Char - (String, String) - (String, String)
| addToSPairc (xs, ys) = (c:xs, ys)
|
| ---
|
| g1 is similar to
addToSPairc ~(xs, ys) =3D (c:xs, ys)
I thought pattern bindings had an implicit ~?
Keean.
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Haskell type classes don't really behave as one might expect coming from an
OO perspective; cf.
http://www.ninebynine.org/Software/Learning-Haskell-Notes.html#type-class-misuse
That commentary doesn't say anything about interface inheritance. I don't
offhand have a good answer for that
On Wed, Oct 13, 2004 at 09:23:43AM +0100, MR K P SCHUPKE wrote:
You can only return a list of pair's lazily, not
a pair of lists. If the two strings are independant, then
generate each in a separate function, and pair off the
results lazily.
No, I have several labeled fields in a record,
addToSPair :: Char - (String, String) - (String, String)
What about:
addToSPair :: Char - String - String - (String,String)
so that the pattern match is:
addToSPair c xs ys = (c:xs,ys)
This is irrefutable?
Keean.
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In message [EMAIL PROTECTED] John Goerzen
[EMAIL PROTECTED] writes:
OK, recently I posed a question about rethinking some OO idioms, and
that spawned some useful discussion.
I now have a followup question.
One of the best features of OO programming is that of inheritance. It
can be used
Serge D. Mechveliani wrote:
As the types are resolved before the computation, as the above
program shows, how can addToSPair expect anything besides a string
pair? Why tilda is not a default?
Haskell pairs are lifted, meaning that they also include an extra
value (bottom) which doesn't match
The only problem with this is name.
It is too easy to have naming clash in haskell. Field selectors are also
top-level functions and they shared the same namespace with other
functions.
for any reasonable scale program, we'll end up with ModuleA.read x,
ModuleB.read b. (Yes, we can alias the
[Switched to haskell-cafe]
At 13:24 13/10/04 -0400, Jacques Carette wrote:
-- It's kind of like an converse map.
I have attempted, unsuccessfully, to write flist above in a point-free
manner. Is it possible?
Of course it is, but why?
flist = flip (map . flip ($))
Some functions are
--- Robert Dockins [EMAIL PROTECTED] wrote:
Then perhaps it is worth considering having multiple
implementations and
choosing between them with pragmas and/or command
line switches (with
a sensible default naturally). Maybe doubly linked
lists are not a
great idea, but if we had a
On Wed, 13 Oct 2004, Shawn Garbett wrote:
Lists are an integral part of the Haskell language,
and in fact most languages have some version of list
at a fundamental level. Here's an interesting (not
necessarily useful!) shift of viewpoint: What if List
were a type class?
Then we'd need
John Goerzen wrote:
One of the best features of OO programming is that of inheritance.
...
Oleg, Keean and me have lying around a draft that adds to this
discussion. We reconstruct OCaml's tutorial in Haskell
The short paper version is online and under consideration for FOOL:
Shawn Garbett [EMAIL PROTECTED] writes:
viewpoint: What if List were a type class?
Or, what if String were one? Could we have painless read/show with
arrays of Char, as well as lists, for instance?
-kzm
--
If I haven't seen further, it is by standing in the footprints of giants
Some people say that ocaml's object system is kinda useless. The best
support I hear so far was:it does not hurt
implementation inheritance, the strange # syntax, virtual method, why do
I need them?
In Java, people are doing programming-against-interface, implementation
injection etc. All these
[EMAIL PROTECTED] wrote:
Some people say that ocaml's object system is kinda useless. The best
support I hear so far was:it does not hurt
Why do you (or do these people) think having all the OO idioms of OCaml
(see OCamls OO tutorial) is useless? Or do you mean too baroque? If not,
what's
--- Ketil Malde wrote:
Or, what if String were one? Could we have painless read/show with
arrays of Char, as well as lists, for instance?
--- end of quote ---
I think with a decent set of type classes for collections, better handling of strings
would come for free. If any list function could
Why do you (or do these people) think having all the OO idioms of OCaml
(see OCamls OO tutorial) is useless? Or do you mean too baroque? If not,
what's missing?
Because it does not give us much that we cannot do nicely with the current
functional part.
separate name space of course. But it
I thank Jeremy Gibbons, Ben Rudiak-Gould, and other people,
for their helpful explanations.
On Wed, Oct 13, 2004 at 02:34:55PM +0100, Ben Rudiak-Gould wrote:
Serge D. Mechveliani wrote:
As the types are resolved before the computation, as the above
program shows, how can addToSPair
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