Thanks Peter. Simon Marlow's talk was really interesting. After
reading the slides I read related GHC code and realized that
cost-centre stack and the stack trace printed using GHC.Stack is
same thing. `libraries/base/GHC/Stack.hsc` has this definition:
currentCallStack :: IO [String]
Ömer Sinan Ağacan wrote:
(off-topic: I'm wondering why an empty tuple is passed to `getCurrentCSS`?)
See the comment on getCurrentCCS# in compiler/prelude/primops.txt.pp -
it's a token to prevent GHC optimisations from floating the primop up
(which obviously might change the call stack).
Now
Thanks again for the answer.
Not sure what _call_ is suppose to be. What's the context?
In Simon Marlow's slides, stack traces are implemented in terms of
call and push operations. I guess `push` in STG syntax is stands
for push operation explained in the slides but as far as I can see
call is
Hello *,
I've been experimenting with the code from the Dependently Typed
Programming with Singletons paper[1] from the following is derived (modulo some
irrelevant renamings):
{-# LANGUAGE TypeOperators, DataKinds, GADTs, TypeFamilies #-}
module CheckedList where
data Nat = Z
Hello again,
...while experimenting with TypeLits I stumbled over the following
simple case failing to type-check with GHC 7.8.2:
{-# LANGUAGE DataKinds, GADTs #-}
data List l t where
Nil :: List 0 t
Cons :: { lstHead :: t, lstTail :: List l t } - List (l+1) t
with
Type lits currently can't do an abstract reasoning. It can only decide
if two concrete literals are equal or reduce an expression made from
concrete literals to a new concrete literal.
For that reason I'm using peano style Nats in my own lib engineering.
On Sunday, May 18, 2014, Herbert
Hi,
a small reminder to the masteres of the stable branch: The ghc-7.8
branch currently still does not validate on Travis:
Am Samstag, den 03.05.2014, 22:08 +0200 schrieb Joachim Breitner:
ghc-7.8:
Unexpected failures:
annotations/should_compile/th annth_compunits [bad exit code]
The short answer here (to Is there a way to avoid the non-exhaustive
pattern-match warning?) is no, not in general. See #3927
(https://ghc.haskell.org/trac/ghc/ticket/3927).
And, after some playing around, I couldn't find a way to do this in your
specific example, either. I will say that I've
Yes, the TypeLits solver is still in early stages, but there's active work
being done to improve the situation. For better concrete syntax with Peano
naturals, I recommend the following construction:
type family U n where -- U stands for unary
U 0 = Z
U n = S (n - 1)
It works well in
Austin,
Could we please make sure to include this bug for 7.8.3?
https://ghc.haskell.org/trac/ghc/ticket/9078
The ticket already includes a patch that solves the problem for us.
As remarked by Levent, this bug will probably affect all EDSL that use Andy’s
StableName-based observable sharing
A little more tinkering got this working, with the definitions in my earlier
email, below (with ScopedTypeVariables):
index :: forall i n t. (i :? S n) = List (S n) t - SNat i - t
index (x :- _)SZ= x
index (_ :- xs) (SS (i :: SNat i')) = case ltProof :: i' : n of
11 matches
Mail list logo
