On 14/02/10 02:21, Lennart Augustsson wrote:
I agree, I don't think this is a bug. If the grammar actually says
that this is legal, then I think the grammar is wrong.
As far as I can tell Doitse is correct in that GHC does not implement
the grammar, so it's either a bug in GHC or the
In UHC it was unpleasant to make it work, because in (e) and (e +) it
only is detected just before the closing parenthesis which of the two
alternatives (i.e. parenthesized or sectioned expression) must be
chosen. The use of LL parsing aggravates this somewhat, so the
required
On 14 feb 2010, at 09:32, Simon Marlow wrote:
On 14/02/10 02:21, Lennart Augustsson wrote:
I agree, I don't think this is a bug. If the grammar actually says
that this is legal, then I think the grammar is wrong.
As far as I can tell Doitse is correct in that GHC does not
implement the
On 10/02/10 07:53, Atze Dijkstra wrote:
On 10 Feb, 2010, at 00:53 , Lennart Augustsson wrote:
Do you deal with this correctly as well:
case () of _ - 1==1==True
No, that is, in the same way as GHC Hugs, by reporting an error.
Note that Haskell 2010 now specifies that expression to be a
On 09/02/10 21:43, S. Doaitse Swierstra wrote:
One we start discussing syntax again it might be a good occasion to
reformulate/make more precise a few points.
The following program is accepted by the Utrecht Haskell Compiler (here
we took great effort to follow the report closely ;-} instead of
I don't think this is a bug. I do not expect to be able to unfold a definition
without some syntactic issues. For example,
two = 1+1
four = 2 * two
but unfolding fails (four = 2 * 1 + 1). In general, we expect to have to
parenthesize things when unfolding them.
John
On Feb 13, 2010, at
I agree, I don't think this is a bug. If the grammar actually says
that this is legal, then I think the grammar is wrong.
On Sun, Feb 14, 2010 at 1:48 AM, John Launchbury j...@galois.com wrote:
I don't think this is a bug. I do not expect to be able to unfold a
definition without some
On Sun, Feb 14, 2010 at 03:21:54AM +0100, Lennart Augustsson wrote:
I agree, I don't think this is a bug. If the grammar actually says
that this is legal, then I think the grammar is wrong.
Then what do you think the grammar should say instead?
That sections should be
( fexp qop )
?
I've
1443
To: Haskell Prime haskell-prime@haskell.org
Subject: Re: Negation
One we start discussing syntax again it might be a good occasion to
reformulate/make more precise a few points.
The following program is accepted by the Utrecht Haskell Compiler
(here we took great effort to follow the report
On Feb 9, 2010, at 10:43 PM, S. Doaitse Swierstra wrote:
-- but if we now unfold the definition of one we get a parser error
in GHC
increment' = ( let x=1 in x + )
The GHC and Hugs parsers are trying so hard to adhere to the meta
rule that bodies of let-expressions
extend as far as
Lennart Augustsson wrote:
Of course unary minus should bind tighter than any infix operator.
I remember suggesting this when the language was designed, but the
Haskell committee was very set against it (mostly Joe Fasel I think).
Are there archives of this discussion anywhere?
Cheers,
Sittampalam, Ganesh
ganesh.sittampa...@credit-suisse.com
writes:
Lennart Augustsson wrote:
Of course unary minus should bind tighter than any infix operator.
I remember suggesting this when the language was designed, but the
Haskell committee was very set against it (mostly Joe Fasel I
It's not true at all that Haskell was created by type theorists.
It is true that little attention was paid for how things are done in C. :)
On Tue, Feb 9, 2010 at 2:39 PM, johndea...@cox.net wrote:
It needs to be appreciated that the Haskell language was created by type
theorists who were
| I imagine it would be something like deleting the production
|
| lexp6- - exp7
The rational for the current choice was the example:
f x = -x^2
| and adding the production
|
| exp10- - fexp
But I would also recommend this change.
It would also make sense to
My impression is that combinatory logic figures prominently in the design of
Haskell and some of the constructs seem to be best understood as combinatorial
logic with syntactic sugar. One could predict from this a number of things. One
of such is the language would at some points seem counter
One we start discussing syntax again it might be a good occasion to
reformulate/make more precise a few points.
The following program is accepted by the Utrecht Haskell Compiler
(here we took great effort to follow the report closely ;-} instead of
spending our time on n+k patterns), but
Do you deal with this correctly as well:
case () of _ - 1==1==True
On Tue, Feb 9, 2010 at 10:43 PM, S. Doaitse Swierstra doai...@cs.uu.nl wrote:
One we start discussing syntax again it might be a good occasion to
reformulate/make more precise a few points.
The following program is accepted
On 10 Feb, 2010, at 00:53 , Lennart Augustsson wrote:
Do you deal with this correctly as well:
case () of _ - 1==1==True
No, that is, in the same way as GHC Hugs, by reporting an error. The
report acknowledges that compilers may not deal with this correctly
when it has the form ``let
On Monday 08 February 2010 11:18:07 am Simon Peyton-Jones wrote:
I think that Hugs is right here. After all, there is no ambiguity in any
of these expressions. And an application-domain user found this behaviour
very surprising.
I think it's clear what one would expect the result of these
On Mon, Feb 08, 2010 at 04:18:07PM +, Simon Peyton-Jones wrote:
Which of these definitions are correct Haskell?
x1 = 4 + -5
x2 = -4 + 5
x3 = 4 - -5
x4 = -4 - 5
x5 = 4 * -5
x6 = -4 * 5
Ghc accepts x2, x4, x6 and rejects the others with a message like
Foo.hs:4:7:
On Mon, Feb 08, 2010 at 04:59:59PM +, Ross Paterson wrote:
But I agree they should all be legal, i.e. that unary minus should bind
more tightly than any infix operator (as in C).
See also
http://hackage.haskell.org/trac/haskell-prime/wiki/NegativeSyntax
Thanks
Ian
Måndag 8. februar 2010 17.59.59 skreiv Ross Paterson:
But I agree they should all be legal, i.e. that unary minus should bind
more tightly than any infix operator (as in C).
I second this, at least in general.
However, one issue is function application. Should unary minus bind tighter
than it
Of course unary minus should bind tighter than any infix operator.
I remember suggesting this when the language was designed, but the
Haskell committee was very set against it (mostly Joe Fasel I think).
I think it's too late to change that now, it could really introduce
some subtle bugs with no
On Mon, Feb 08, 2010 at 04:18:07PM +, Simon Peyton-Jones wrote:
Which of these definitions are correct Haskell?
x1 = 4 + -5
x2 = -4 + 5
x3 = 4 - -5
x4 = -4 - 5
x5 = 4 * -5
x6 = -4 * 5
Ghc accepts x2, x4, x6 and rejects the others with a message like
Foo.hs:4:7:
On Mon, Feb 08, 2010 at 01:24:55PM -0800, John Meacham wrote:
What would be the actual change proposed? If it is something concrete
and not something like negatives should be interpreted as unary minus
when otherwise it would lead to a parse error then that wouldn't be
good. I have enough
| Of course unary minus should bind tighter than any infix operator.
| I remember suggesting this when the language was designed, but the
| Haskell committee was very set against it (mostly Joe Fasel I think).
|
| I think it's too late to change that now, it could really introduce
| some subtle
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