[racket-dev] Please help me to fix the code

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 <hkBst at gentoo.org> wrote:
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> 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
> 
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