On May 30, 2011, at 7:17 PM, 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..." > > The code is below: > > (define (count-matches s l) > (cond > [(empty? l) 0] > [(equal? s (first l)) (lambda (i)(+ i 1))]
What's this lambda doing here? > [else (count-matches s (rest l))])) > > Where the s is a letter and l is a list. To use it as an example, I typed > > (count-matches 'f '(f )) > > and got the error. The right result should be 1. > > Do I need to initialize i? If so, how can I do it? > > Note that the keywords that I can use are pretty much used in the code. If > the solution needs keywords outside this post, it may not be useful to me. > > Thank you very much. > _________________________________________________ > For list-related administrative tasks: > http://lists.racket-lang.org/listinfo/dev _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
