Sitzman <[EMAIL PROTECTED]> writes:
> Hey all.. Gosh, this feels embarrassing to ask.. but how do I get a string
> to print out with a carriage return in it? (like using \n in c++)...
>
> I want
> > listBooks :: [Book] -> [String]
> > listBooks [] = []
> > listBooks (Book lang year last first t
Tim,
I am aware that it is not an assignment, but rather a binding to a value.
However, my intent is to model a system that has both declarative and
imperative constructs, then build it in another language. If I can use :=, I
can make it look more like the final system, which is good for
demonstr
Hey all.. Gosh, this feels embarrassing to ask.. but how do I get a string
to print out with a carriage return in it? (like using \n in c++)...
I want
> listBooks :: [Book] -> [String]
> listBooks [] = []
> listBooks (Book lang year last first title:bs)
> =
(lang++","++year++","++last++","++fi
On Fri, Apr 28, 2000 at 07:08:22PM -0700, Mike Jones wrote:
> Is there a way to define (:=) to be (<-) in the context of a do?
> The goal is to make the language look Pascal like for those who will use it.
I'd say that goal is ill-concieved. If you are trying to help
people learn functional pro
All,
Is there a way to define (:=) to be (<-) in the context of a do? This would
then allow:
result = do
initialize
vi1 := Vi.create
Vi.setValue vi1 5.5
Vi.enable vi1
vi2 := Vi.create
Vi.setValue vi2 6.0
cond1 (isnt (Vi.enabled vi2)) (Vi.se
On Sat, 29 Apr 2000, Fergus Henderson wrote:
> On 28-Apr-2000, Jan Skibinski <[EMAIL PROTECTED]> wrote:
> >
> > When can I safely cheat haskell compiler/interpreter
> > by pretending that I perform pure computations,
> > when in fact they are not?
>
> That depends on what degree o
On 28-Apr-2000, Erik Meijer <[EMAIL PROTECTED]> wrote:
> Hi Jan,
>
> > When can I safely cheat haskell compiler/interpreter
> > by pretending that I perform pure computations,
> > when in fact they are not?
>
> If the computation is not pure, you cannot pretend it is.
Indeed. And i
On 28-Apr-2000, Frank Atanassow <[EMAIL PROTECTED]> wrote:
> Jan Skibinski writes:
> >When can I safely cheat haskell compiler/interpreter
> >by pretending that I perform pure computations,
> >when in fact they are not? Here is a real example,
> >from my Md5Digest module which
On 28-Apr-2000, Jan Skibinski <[EMAIL PROTECTED]> wrote:
>
> When can I safely cheat haskell compiler/interpreter
> by pretending that I perform pure computations,
> when in fact they are not?
That depends on what degree of safety and portability you want.
If you want the great
Jan Skibinski wrote:
> digest :: String -> String
> digest string
> = unsafePerformIO (
> marshall_string_ string >>= \x1 ->
> prim_Md5Digest_digest x1 >>= \x2 ->
> unmarshall_string_ x2 >>= \x3 ->
>
Jan Skibinski writes:
> When can I safely cheat haskell compiler/interpreter
> by pretending that I perform pure computations,
> when in fact they are not? Here is a real example,
> from my Md5Digest module which works fine in Hugs:
I don't understand what is impure about
Hi Jan,
> When can I safely cheat haskell compiler/interpreter
> by pretending that I perform pure computations,
> when in fact they are not?
If the computation is not pure, you cannot pretend it is.
> Here is a real example,
> from my Md5Digest module which works fi
Workshop on Generic Programming
http://www.cs.uu.nl/~johanj/wgp2000/wgp2000cfp.html
6th July 2000
Ponte de Lima , Portugal
Call for proposals for 10 minutes slots
The one day Workshop on Generic Programming (see the
Facing a risk of being stomped all over again
without reason, I nevertheless post this question
to get to the bottom of things:
When can I safely cheat haskell compiler/interpreter
by pretending that I perform pure computations,
when in fact they
The implementation that uses laziness to get
true backpointers seems to have caught everybody's
imagination. Several people have hinted at
the big weakness of this implementation, but lest
any beginners reading this thread be misled, let me
just state that weakness explicitly -- it takes O(n)
t
For those who prefer the thrill of the latest features over
the safety of a tested release: C->Haskell is now available
via anonymous CVS. Details at
http://www.cse.unsw.edu.au/~chak/haskell/c2hs/#cvs
Cheers,
Manuel
On Fri, 28 Apr 2000, Fergus Henderson wrote:
> >
> > This is all fine and dandy if `currentSecond' is within `where'
> > clause, because it will be always evaluated afresh.
>
> It might happen to work with current Haskell implementations,
> but I don't think there's any guarantee of t
> Jerzy Karczmarczuk wrote:
>
> Yes, Simula-67.
>
> Actually *they did* that. A "node" had two sub-classes, the link and the
> head, and the link chain was doubly attached to the head. This structure
> has been havily used for the maintenance of the co-routine bedlam
> exploited in si
Erik:
> You have discovered the essence of monads, ie the difference between the bad
> and ugly world of side-effecting computations and the nice and clean world
> of pure functions. And even using my favourite example (*)!
Let's put it in other words: I knew the difference,
> "Jerzy" == Jerzy Karczmarczuk <[EMAIL PROTECTED]> writes:
> The idea of double lists was to permit a fast two-directional
> navigation,
> and the ease of insertion/deletion.
> But in Haskell, where the beasts are not mutable:
> ... Actually, has anybody really used the
Jerzy Karczmarczuk ([EMAIL PROTECTED]) wrote:
: But in Haskell, where the beasts are not mutable:
:
: ... Actually, has anybody really used them for practical purposes?
I have used doubly linked lists in Haskell about four
years ago to implement a queue from which objects could
be added at fron
Chris Angus:
>
> Would it not be better to tag a start point then we can manipulate this
> easier
> and move it back to a singly linked list etc.
>
> data Db a = Dd (Db a) a (Db a)
> | DStart (Db a) a (Db a)
>
> ...
Well, I am sufficiently old to confess that one of my favourite OO
l
Would it not be better to tag a start point then we can manipulate this
easier
and move it back to a singly linked list etc.
data Db a = Dd (Db a) a (Db a)
| DStart (Db a) a (Db a)
instance Show a => Show (Db a) where
show xs = show (enumerate xs)
instance Eq
> -Original Message-
> From: Peter Hancock [mailto:[EMAIL PROTECTED]]
> Sent: 28 April 2000 10:23
> To: [EMAIL PROTECTED]
> Cc: [EMAIL PROTECTED]
> Subject: Re: doubly linked list
>
>
> > "Jan" == Jan Kort <[EMAIL PROTECTED]> writes:
>
> > Anyway, a doubly linked list could be
> "Jan" == Jan Kort <[EMAIL PROTECTED]> writes:
> Anyway, a doubly linked list could be defined like this:
That was very interesting. It seems to generalise to put
back-pointers and other context info in a variety of data
structures. This seems a pretty performance-enhancing thing to do
> Jan Brosius wrote:
> I wonder if it is possible to simulate a doubly linked list in
> Haskell.
... and the number of answers was impressive...
Want some more?
This is a short for *making* true double
lists, and as an extra bonus it is circular. Slightly longer than
the solution of Jan Kort, n
At 11:00 am +0200 28/4/00, Erik Meijer wrote:
>If you want to play it rough, you could do what ML programmers do and
>explicitely delay and force the computation of currentSecond:
>
> currentSecond :: () -> Int
> currentSecond () = second $ unsafePerformIO localDateTime
>
>However, you should
> currentSecond = second $ unsafePerformIO localDateTime
>
> where `localDateTime' has been defined via primitive
> call to C:
>
> localDateTime :: IO DateTime
>
> To my distress the clock stopped after the first call to
> `currentSecond'. I took me much more than
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