Hi Matthias, The problem is not on the internet. Since I am a beginner, I need to read more. If at last I cannot figure it out, I'll email you the requirements.
Thanks a lot. On Tue, May 31, 2011 at 9:04 AM, Matthias Felleisen <matth...@ccs.neu.edu>wrote: > > 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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