Yingjian, if you point us to the web page with the problems, we might be able to help you more effectively.
On May 31, 2011, at 12:01 PM, Yingjian Ma wrote: > Hi Marijn, > > I am new to Racket. I did not expect that output is > "#<procedure:...uments...". It is like an error message to me. > > Because the restrictions on this function (and on others), I need to study > more about Racket to go further. I also need to code a function to remove > the duplicates from a list. There is a such function in Racket but I cannot > use it. > > On Tue, May 31, 2011 at 1:03 AM, Marijn <hk...@gentoo.org> wrote: > -----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
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