Bryan O'Sullivan wrote:
On Mon, Oct 13, 2008 at 1:58 AM, Simon Marlow [EMAIL PROTECTED] wrote:
Thanks! New versions of Alex Happy uploaded.
Where to? I only see 2.3 on Hackage, and haskell.org claims that Alex
is still at 2.2.
Just on Hackage for the time being, I'll update the web pages
| I totally agree. Getting the value of the field should just evaluate
| x and then use a pointer indirection; there should be no conditional
| jumps involved in getting the value.
| GHC is just doing the wrong thing.
You're right. As Simon says, GHC's Core language has no type distinction
On 16/10/2008, at 21:34, Simon Peyton-Jones wrote:
For strict *constructors*, on the other hand, we *do* guarantee to
evaluate the argument before building the constructor. We generate
a wrapper thus
wC = \ab. case a of { a' - C a' b }
(Remember 'case' always evaluates in Core.) So
| BUT people who care probably UNPACK their strict fields too, which
| is even better. The time you can't do that is for sum types
| data T = MkT ![Int]
|
| You also can't do it for polymorphic components. I've used code like:
|
|data T a = MkT !a
|
|foo :: T (a,b) - a
|foo
Lennart Augustsson wrote:
True, if there can be indirections then that's bad news.
That would make strict fields much less efficient.
But I don't see why indirections should be needed. Simon?
This kind of thing has always been a problem for GHC, and IIRC hbc does/did
better here.
I don't
On Thursday 16 October 2008 07:03:05 Roman Leshchinskiy wrote:
On 16/10/2008, at 21:34, Simon Peyton-Jones wrote:
BUT people who care probably UNPACK their strict fields too, which
is even better. The time you can't do that is for sum types
data T = MkT ![Int]
You also can't do it
twhitehead:
On Thursday 16 October 2008 07:03:05 Roman Leshchinskiy wrote:
On 16/10/2008, at 21:34, Simon Peyton-Jones wrote:
BUT people who care probably UNPACK their strict fields too, which
is even better. The time you can't do that is for sum types
data T = MkT ![Int]
