Proposal: Improved error message of "Error in array index"

Simon Marlow simonmar at
Wed Nov 9 06:40:39 EST 2005

On 09 November 2005 11:40, Simon Marlow wrote:

> On 09 November 2005 10:18, Ketil Malde wrote:
>> Simon Marlow wrote:
>>> Hmm yes, this is indeed rather unhelpful.  I can explain why it
>>> happens, though.  The compiler has lifted out the error case into a
>>> top-level binding: 
>>>  x = error "Error in array index"
>> Would the compiler be less agressive with this if I turn off
>> optimization?   I usually use optimization with profiling as well,
>> but could of course turn it off if it would result in more useful
>> stack backtraces.
> Possible... but not guaranteed.  I think the simplifier does limited
> forms of let-floating even without -O. 

Oh, and that code is in a library, so turning off -O won't help there.


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