deeqSeq proposal

John Meacham john at
Thu Apr 6 16:55:28 EDT 2006

On Thu, Apr 06, 2006 at 12:06:53AM -0700, Andy Gill wrote:
> Because deepSeq's cost to evaluate a list that will eventually be  
> required is linear.
> The maximum number of deepSeq calls (and recursive calls) you can do  
> over any
> structure is simply the number of nodes.
> Consider:
>   foldr (\ a as -> deepSeq (a : as)) [] $ some list
> With the bit ==> one deepSeq per cons, then we hit the 'is-pre- 
> deepSeqd' bit.
> Without the bit ==> O(n^2)

Ah, I see, I was thinking of something else.

unfortunatly, this scheme or any scheme with changes to the run-time
representation will be impossible in jhc. there is no concept of WHNF
or thunks, let alone a generic way to evaluate them at run time in GRIN.


John Meacham - ⑆⑆john⑈

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