Re: What are the preconditions of newArray#

I agree (unless it has a performance cost). I had to fix a couple of bugs in my code associated with generating zero-length arrays. On Mon, Aug 22, 2011 at 5:54 PM, Edward Kmett wrote:

It would still be nice to have a consistent base case.

On Mon, Aug 22, 2011 at 3:43 AM, Johan Tibell wrote:

...

On Mon, Aug 22, 2011 at 5:55 AM, Edward Z. Yang wrote:

...

stg_newArrayzh in rts/PrimOps.cmm doesn't appear to give any indication, so this might be a good patch to add.  But I'm curious: what would allocating Array#s of size 0 do? Null pointers? That sounds dangerous...

I would imagine that a zero sized array would be a StgArrPtrs header with its size field set to 0. It's not a very useful thing to have, I admit. If someone (Simon?) can confirm that we don't intend to support zero-length array I'll push a patch that adds a comment.

Johan

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