On Rosetta code in "Count occurrences of a substring" I found this for Racket:
(define count-substring (compose length regexp-match*)) Example: (count-substring "th" "the three truths") 3 I like to use it for getting the number of occurences of a list of characters in a string. For this I used it like this: (count-subsring "[a-z2;]" "arst;452") Let us assume the part between the brackets could be anything. How would I escape certain characters in order to make sure the regular expression still works fine? Examples: -> (count-substring "[\\[]" "a[rts[a3]") 2 -> (count-substring "[a-z\\[]" "a[rts[a3]") 7 -> (count-substring "[\\]]" "a[rts[a3]") 0 The first two seem to work fine, the last one doesn't. -- Manfred ____________________ Racket Users list: http://lists.racket-lang.org/users
