[Chicken-users] Re: crazy behaviour in csi!
Sunnan wrote: Thanks, I guess I was stressed, and forgot that unknown macros can already be defined. The error message just looked so weird. I was pretty sleep-deprived at the time. I hadn't looked at srfi-31 before. I thought I knew most of the srfis. This one was pretty disappointing. (define (...) 10) ; They want to write: ((rec (F N) (if (zero? N) 1 (* N (F (- N 1) (...)) ;; instead of: (let f ((n (...))) (if (zero? n) 1 (* n (f (- n 1) ;; it's the exact same number of characters! Almost - note that REC returns the recursive function, so you need to return the function in the let: ((let f ((n (...))) (if (zero? n) 1 (* n (f (- n 1 f) (...)) -- Jens Axel Søgaard ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
[Chicken-users] Re: Better algorithm for growing hash tables
I too am suffering from very slow hash tables. I'm brand-new to chicken (although not to scheme) so it's possible that I'm doing something wrong. The gist of the problem is: I'm using bignums (from the numbers) extension as the hash table key; I created the table with (make-hash-table =); I'm reading lines from /usr/share/dict/words, and for each line, I'm computing a number, and using that number as the hash key, and the word as the value. It starts out storing perhaps 300 words per second, then gets progressively slower; as I write this, it's storing perhaps 30 words per second (the hash table has about 34,000 entries). I'm using version 212 (which I got from darcs), so I expect all the patches that have been previously mentioned have already been applied. I'm happy to make the code available if anyone's interested (it's small). Any ideas how I can speed this up? -- Paul Graham is right. --Shriram Krishnamurthi ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
the point of REC , was (Re: [Chicken-users] Re: crazy behaviour in csi!)
On Mon, 2005-12-05 at 23:54 +0100, Jens Axel Søgaard wrote: Sunnan wrote: ;; instead of: (let f ((n (...))) (if (zero? n) 1 (* n (f (- n 1) ;; it's the exact same number of characters! Almost - note that REC returns the recursive function, so you need to return the function in the let: ((let f ((n (...))) (if (zero? n) 1 (* n (f (- n 1 f) (...)) But that does the same thing; the whole expression as such returns the result of the recursive function in both cases. The recursive function returned by REC is use-once-and-destroy. And in chicken, ((rec (F N) (if (zero? N) 1 (* N (F (- N 1) (...)) macroexpands to almost the same as (let f ((n (...))) (if (zero? n) 1 (* n (f (- n 1) if I recall correctly. BTW, your example evaluates (...) twice. AML, Sunnan ___ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users
