Re: [q-lang-users] "and then" and stack usage

[<Dr....@t-...>]

/me wrote:
> ww wrote:
> 
>> I've been exploring Q recently and I've noticed that "and then" doesn't
>> seem to run in constant space. From it's definition (in the docs), I was
>> expecting that it could reuse the stack frame but that doesn't seem to 
>> be the case. Am I missing something?
> 
> I thought about this problem a little more -- it's really been haunting 
> me. ;-) So here's the result of my contemplations...
> 
> [snipped]

I thought about it still some more, and finally decided that this is 
really a bug that needs to be solved. Said and done. ;-) So in cvs you 
can now find a new version of the interpreter that is fully 
tail-recursive. That is, tail calls are now optimized for builtins and 
special arguments just as for user-defined rules. Thus, e.g., (=) and 
`all' on lists now run in constant stack space, without the need to 
rewrite anything. Enjoy! :)

Albert

-- 
Dr. Albert Gr"af
Email:  Dr....@t-..., ag...@mu...
WWW:    http://www.musikwissenschaft.uni-mainz.de/~ag