>>>>> "RLS" == Randal L Schwartz <merlyn@stonehenge.com> writes:
>>>>> "Uri" == Uri Guttman <[EMAIL PROTECTED]> writes: Uri> sorting in p6 is not at all like in p5. instead of coding up an explicit Uri> comparison code block and duplicating all the key access code (for $a Uri> and $b), you will specify how to extract/generate each key for a given Uri> record. this new syntax was posted by damian (who else) and it is very Uri> similar to the api in my p5 module sort::maker (we did discuss this Uri> api). i don't know if any A/E/S doc covers it but it is definitely in Uri> the archives. RLS> I hope the old (perl5) way is still available as well. There are times RLS> when parts of the comparison should be done lazily. Consider two RLS> objects that have a value for a primary sorting order, but only RLS> for those which the value is the same, we fall back to a secondary RLS> sort key that is expensive to compute (like maybe calling a database). RLS> For these scenarios, specifying the sort comparison will be simpler RLS> and cheaper than specifying the sort key. RLS> So, we need both, but if we get only one, the Perl5 way is superior. i will let damian handle this one (if he sees it). but an idea would be to allow some form ofkey extraction via a closure with lazy evaluation of the secondary (and slower) key. and if you need that feature then you can't use the standard ST or GRT which preextract the keys. you could mung the ST to do this with lazy eval support but not the GRT since it packs the keys and there is no place to put in code for lazy keys. note that the API damian proposed did not specify an implementation so this could be supported internally at some point. and supporting the old simple p5 sort shouldn't be a problem and is probably a good idea anyhow. but the $a and $b will have to become $^a and $^b and be proper params of a closure. i dunno if that will cause a speed hit as $a/$b we designed to bypass the normal slow arg passing in p5. uri -- Uri Guttman ------ [EMAIL PROTECTED] -------- http://www.stemsystems.com --Perl Consulting, Stem Development, Systems Architecture, Design and Coding- Search or Offer Perl Jobs ---------------------------- http://jobs.perl.org
