G'day all.
On Fri, Aug 22, 2003 at 03:41:14PM +1000, [EMAIL PROTECTED] wrote:
> Seeing as its thst time of year again and everyone is posting their
> homework, has anyone got any good puzzles to do?
> I wouldn't mind having a go at something a bit tricky.
OK, here's a tricky problem.
Take a lis
G'day all.
On Fri, Aug 22, 2003 at 09:40:12AM +1000, Job L. Napitupulu wrote:
> Can anyone help me how to make a function which takes an integer n > 0 and
> returns the list of integers in Line of Pascal's Triangle. For examples,
>
> pascalLine 4 -> [1,4,6,4,1]
> pascalLine 7 -> [1,7,21,35,35,21
Seeing as its thst time of year again and everyone is posting their
homework, has anyone got any good puzzles to do?
I wouldn't mind having a go at something a bit tricky.
Tom
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"Job L. Napitupulu" <[EMAIL PROTECTED]> writes:
> Can anyone help me how to make a function which takes an integer n >
> 0 and returns the list of integers in Line of Pascal's Triangle.
Yes, I imagine a lot of people can, but you're supposed to do your own
homework. Here's a rough outline, thoug
Can anyone help me how to make a function which takes an integer n > 0 and
returns the list of integers in Line of Pascal's Triangle. For examples,
pascalLine 4 -> [1,4,6,4,1]
pascalLine 7 -> [1,7,21,35,35,21,7,1]
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On Thursday 21 August 2003 23:39, Tom Pledger wrote:
> Try
>
> x :: Fractional a => a
> x = 0.5
>
> instead. That way, the type signature is in the right place to
> prevent defaulting.
Right - thanks!
Konrad.
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Tim Docker writes:
:
| Is it normal or common to support multiple simultaneous queries on
| a single DB connection?
In transaction processing, yes. There's an idiom where you use one
query to select all the (financial) transactions in a batch, but
there's so much variation in how you need to p
Konrad Hinsen writes:
| On Thursday 21 August 2003 23:23, Jon Cast wrote:
| > > I can make such a declaration, but it still gets converted to Double.
| >
| > How are you doing this? I'm not seeing the behavior you describe.
|
| module Foo where
| x = 0.5 :: Fractional a => a
Try
x ::
On Thu, Aug 21, 2003 at 10:30:33PM +0200, Konrad Hinsen wrote:
> I might also declare all my constants to be "Rational" and use
> "fromRational", but I don't know much about the "Rational" type. Do I
> have to worry about insufficient or compiler-dependent precision?
I would guess that this is the
On Thursday 21 August 2003 23:23, Jon Cast wrote:
> > I can make such a declaration, but it still gets converted to Double.
>
> How are you doing this? I'm not seeing the behavior you describe.
module Foo where
x = 0.5 :: Fractional a => a
Then I run "hugs Foo.hs" and get:
Foo> :type x
x :: Dou
Konrad Hinsen <[EMAIL PROTECTED]> wrote:
> On Thursday 21 August 2003 22:42, Jon Cast wrote:
>
> > > (or any other type I declare it to be).
> >
> > Right. But: you can declare it to have type Fractional alpha =>
> > alpha, which is the same type the constant has in the middle of an
> > expressio
> tor 2003-08-21 klockan 22.26 skrev Jon Cast:
> > Yes. Many complicated proposals have been made, but there's a
> > straightforward, general mechanism:
> >
> > > addMaybe :: Num alpha => Maybe alpha -> Maybe alpha -> Maybe alpha
> > > addMaybe a b = a >>= \x ->
> > >b >>= \y ->
>
On Thursday 21 August 2003 22:42, Jon Cast wrote:
> > (or any other type I declare it to be).
>
> Right. But: you can declare it to have type Fractional alpha => alpha,
> which is the same type the constant has in the middle of an expression.
I can make such a declaration, but it still gets conv
On dinsdag, aug 19, 2003, at 15:09 Europe/Amsterdam, C T McBride wrote:
Hi
As an example, I'll use the Maybe monad. Suppose I want to write
code to
handle experimental data, in which there might be missing values. I
might
then decide to represent measurements by data of type "Maybe
Double", wi
tor 2003-08-21 klockan 22.26 skrev Jon Cast:
> Yes. Many complicated proposals have been made, but there's a
> straightforward, general mechanism:
>
> > addMaybe :: Num alpha => Maybe alpha -> Maybe alpha -> Maybe alpha
> > addMaybe a b = a >>= \x ->
> >b >>= \y ->
> >
Konrad Hinsen <[EMAIL PROTECTED]> wrote:
> I am trying to write a larger piece of code using only type
> constraints for all the numbers, not specific types, in order to be
> able to choose the precision as late as possible.
Good for you! (I say this in all seriousness.)
> This works rather wel
Konrad Hinsen <[EMAIL PROTECTED]> wrote:
> I have been following the recent "Monad tutorial" discussion with
> interest, and even read the tutorial, which is a useful addition to
> the existing Haskell documentation. So useful in fact that it raises a
> question...
>
> The whole monad mechanism
I am trying to write a larger piece of code using only type constraints for
all the numbers, not specific types, in order to be able to choose the
precision as late as possible. This works rather well (something I can't say
of many other languages), but one problem I keep running into is constan
>
> hi guys,
> may i know how to use recursive in a function. for example i have a function lets
> call it old which accept [[Bool]]->[(Int),(Int)]->(Int,Int) and return
> [(Int),(Int)]
> and now i have another function lets say its called new, which calls the previous
> function and new will r
> Things that seem important (to me) are:
>
>- Do you want to observe cycles and or sharing?
Yes.
> Of course this is very hard to do because of garbage collection.
Only in the sense that holding onto an object pointer to detect a cycle might
cause you to hold onto the object too - ca
Hi
> > Or, more generally,
> >
> > infixl 9 <$>
> >
> > (<$>) :: Monad m => m (s -> t) -> m s -> m t
> > mf <$> ms =
> > do f <- mf
> >s <- ms
> >return (f s)
>
> or just liftM2 ($)
> or just ap
OK, I'm a bad citizen and I never look things up in the library. If it
isn't
> From: Tim Docker [mailto:[EMAIL PROTECTED]
>
> > It also has the benefit that the function you pass to doquery can
> make
> > other calls to doquery, without mucking up the 'current row' state.
> > There would be one current row per Cursor, not one per Process.
>
> Is it normal or common to s
Tom Pledger wrote:
> How about introducing a Cursor abstract data type?
>
> doquery :: Process -> String -> b -> (Cursor -> b -> IO (b,
Bool))
>-> IO b
> stringv :: Cursor -> CInt -> IO String
> doublev :: Cursor -> CInt -> IO Double
> intv:: Cursor -> C
hi guys,
may i know how to use recursive in a function. for example i have a function lets call it old which accept [[Bool]]->[(Int),(Int)]->(Int,Int) and return [(Int),(Int)]
and now i have another function lets say its called new, which calls the previous function and new will recursively check
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