-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Yingjian,
On 05/31/11 01:17, Yingjian Ma wrote: > Hi All, > > I wrote a piece of code to count the occurrance of a letter in a list. But > it gave me an error saying "#<procedure:...uments..." What makes you think it's an error? > The code is below: > > (define (count-matches s l) > (cond > [(empty? l) 0] > [(equal? s (first l)) (lambda (i)(+ i 1))] > [else (count-matches s (rest l))])) Part of this code reads: compare s to the first element of list l and if they are equal return a function that returns its argument plus one (and forget about the rest of the list). Marijn -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk3koL8ACgkQp/VmCx0OL2ztFwCfUG1WrfbagBXTp7F9prAvvaL8 sycAoJWBleSTJ/eE2CExwx1zt71Z1Lks =e+cf -----END PGP SIGNATURE----- _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
