Re: [Chicken-users] two procedures looking for a good home
If redundancy were a reason for deleting egg functionality, we have about seven object systems to get rid of. ;-) Ah, but if you pick any two of those, they will have their differences! In this case, however, *absolutely* all usages of the new code are supported by the old one and it is *impossible* for a user to find any difference between them (other than the fact that orders' function is called cmp-key and the combinator's make-/key) no matter how hard they try. IMHO case that should be enough of a reason not to add the copy of the code in another egg with a different name. Alejo. http://azul.freaks-unidos.net/ ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] two procedures looking for a good home
On Sun, Feb 24, 2008 at 1:16 PM, Alejandro Forero Cuervo [EMAIL PROTECTED] wrote: If redundancy were a reason for deleting egg functionality, we have about seven object systems to get rid of. ;-) Ah, but if you pick any two of those, they will have their differences! In this case, however, *absolutely* all usages of the new code are supported by the old one and it is *impossible* for a user to find any difference between them (other than the fact that orders' function is called cmp-key and the combinator's make-/key) no matter how hard they try. No worries, I was just joking. :-) I agree, the redundancy is pointless. It's pointless, I say. I'd like to add a (sort/decorated lst cmp key) proc to your orders egg, that calculates the key values only once; this can be more efficient than (sort ... (cmp-key ...)) for cases where key generation is expensive. I think it fits in your egg; are you OK with that? (The name 'decorated' is an allusion to the 'decorate-sort-undecorate' idiom in Python, which this replicates; we can rename to something more clear.) Graham ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] two procedures looking for a good home
No worries, I was just joking. :-) I agree, the redundancy is pointless. It's pointless, I say. Ahh, hahahahah, I thought you were serious. Sowwy. I'd like to add a (sort/decorated lst cmp key) proc to your orders egg, that calculates the key values only once; this can be more efficient than (sort ... (cmp-key ...)) for cases where key generation is expensive. I think it fits in your egg; are you OK with that? You are still joking here, right? (See the sort-key-cache function in said egg.) ;-) Heheh. Alejo, feeling very redundant with Graham today. :-) http://azul.freaks-unidos.net/ ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] two procedures looking for a good home
On Sun, Feb 24, 2008 at 1:55 PM, Alejandro Forero Cuervo [EMAIL PROTECTED] wrote: I'd like to add a (sort/decorated lst cmp key) proc to your orders egg, that calculates the key values only once; this can be more efficient than (sort ... (cmp-key ...)) for cases where key generation is expensive. I think it fits in your egg; are you OK with that? You are still joking here, right? (See the sort-key-cache function in said egg.) ;-) D'oh, no I wasn't joking that time, I just hadn't read the whole egg properly. Funny. :-) Alejo, feeling very redundant with Graham today. :-) Heh. I am fighting a cold today; I didn't think it was impairing my judgment, but I think I was wrong... Best wishes, Graham http://azul.freaks-unidos.net/ ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] two procedures looking for a good home
On Thu, Feb 21, 2008 at 3:26 PM, Kon Lovett [EMAIL PROTECTED] wrote: I find that I use these two procedures frequently, and I'd love to see them in an egg so I don't need to keep including them locally. Perhaps is someone interested in working on a shared misc-combinators egg, to store handy little things like this? Done. See release/3/combinators. Ignore the License stuff, much of this is automatically generated boiler-plate. Damn, Kon, you are fast! This is the clinching evidence supporting my theory that you are actually a bot. Thanks, konbot, G ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] two procedures looking for a good home
(define (key-on proc #!optional (comparator )) ;; Define a comparator function for a sort. E.g. to sort a list of ;; lists by their first items, using string-case-insensitive ;; comparison: (sort lst (key-on first string-ci?)) (lambda (a b) (comparator (proc a) (proc b This sounds very similar to the under-documented cmp-key function in the orders egg: (define (cmp-key cmp key) (lambda args (apply cmp (map key args The orders egg provides some convenience wrappers around this. Any help documenting that egg would be appreciated. :-) Alejo. http://azul.freaks-unidos.net/ ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] two procedures looking for a good home
On Feb 21, 2008, at 12:15 PM, Graham Fawcett wrote: Hi folks, I find that I use these two procedures frequently, and I'd love to see them in an egg so I don't need to keep including them locally. Perhaps is someone interested in working on a shared misc-combinators egg, to store handy little things like this? If such an egg exists and I'm not aware of it, please let me know. Graham (define (group-by keyproc lst #!optional (is-equal equal?)) ;; group a list of elements by some key attribute. ;; the list must be in sorted order with respect to the key. ;; examples: ;; (group-by identity '(1 2 3 3 4 4 4)) -- ((1) (2) (3 3) (4 4 4)) ;; (group-by car '((a 1) (a 2) (b 1))) -- '(((a 1) (a 2)) ((b 1))) (let loop ((lst lst) (acc '())) (if (null? lst) (reverse acc) ;; possibly remove the reversal? (let ((key (keyproc (car lst (receive (grouped rest) (span (lambda (item) (is-equal key (keyproc item))) lst) (loop rest (cons grouped acc))) (define (key-on proc #!optional (comparator )) ;; Define a comparator function for a sort. E.g. to sort a list of ;; lists by their first items, using string-case-insensitive ;; comparison: (sort lst (key-on first string-ci?)) (lambda (a b) (comparator (proc a) (proc b Done. See release/3/combinators. Ignore the License stuff, much of this is automatically generated boiler-plate. ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users Best Wishes, Kon ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
