#5395: Context reduction stack overflow without undecidable instances
-----------------------------------------+----------------------------------
Reporter: guest | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 7.0.4
Keywords: type family, termination | Testcase:
Blockedby: | Difficulty:
Os: Unknown/Multiple | Blocking:
Architecture: Unknown/Multiple | Failure: GHC rejects valid
program
-----------------------------------------+----------------------------------
Comment(by simonpj@…):
commit d3a31e480ace72a82a301ffb11fd5f73d9ede5bd
{{{
Author: Simon Peyton Jones <[email protected]>
Date: Fri Sep 2 09:07:46 2011 +0100
Increase the "context stack depth" to 200 (from 20)
This parameter controls the allowed depth of reasoning in the
type constraint solver. Perfectly well-behaved programs can
use deep stacks, and 20 is obviously too small. (Indeed, if
you don't have UndecidableInstances, the constraint solver
is supposed to terminate, so no limit should be needed.)
Responding to Trac #5395 this patch increases the default
to 200.
includes/HaskellConstants.hs | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
}}}
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5395#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
Glasgow-haskell-bugs mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
