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

Simon Marlow simonmar at
Wed Nov 9 06:40:08 EST 2005

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.


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