I like this but I'm getting a warning message.

Hi everyone,

I wrote these functions, and they are pretty good in my humble opinion.  (
Forgive the lack of modesty, but I really worked hard on these. )

However, I'm getting "Warning 10: this function should have output unit( )"
or something like that.

Is that really a bad thing?  Is there a workaround?  Thanks for sharing.

*(* Use the following functions to get the frequencies from a list. *)*


*let get_frequency n lst = let count = ref 0 in *

*let rec getFrequency m l = match l with *

*|[ ] -> [ ]*

*|head :: tail -> if head = m then begin incr count ; getFrequency m tail
end else getFrequency m tail in *

*getFrequency n lst ; *

*[ n ; !count ] ;;*


*let rec makeSet lst = let rec mem num l = match l with *

*|[ ] -> false*

*|head :: tail -> if head = num then true else mem num tail in *

*match lst with *

*|[ ] -> [ ]*

*|head :: tail -> if mem head tail then makeSet tail else head :: ( makeSet
tail ) ;;*


*let frequency_list lst = let set = makeSet lst in *

*let rec freq_list s l = match s with *

*|[ ] -> [ ]*

*|head :: tail -> ( get_frequency head l ) :: ( freq_list tail l ) in *

*freq_list ( List.sort compare set ) lst ;;*


*(* Use the following function to generate a list of random integers
between "lower" and "upper", inclusive. *)*

*let rec random_sequence lower upper size = if size = 0 then [ ] else (
lower + Random.int( upper - lower + 1 ) ) :: *

*( random_sequence lower upper ( size - 1 ) ) ;;*


So for example, if I apply the function *frequency_list* to [ 1; 1; 1; 1;
1; 2; 2; 2; 2; 2; 2 ] Ocaml should return

[ [1; 5] ; [2; 6] ]

( Interpretation: The original list contains 5 1's and 6 2's. )


Thanks for the help!  I really struggled with this one.  There could be an
easier way to find the frequencies of a list, but that's my solution to the
problem.  It works!  But not sure how really "efficient" or fast my code is
compared to other solutions to the same problem.


Best,


Douglas.