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[Caml-list] List.sort
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Date: 2002-06-19 (14:55)
From: Johann Spies <jspies@s...>
Subject: [Caml-list] List.sort
I apologise for asking a newbie question on this list, but the
beginners-list seems to have a problem.  After 24 hours my message
did not appear on the list and there was actually no activity the last
few days.

I am trying to figure out how to use List.sort.

According to the manual the Persvasives.compare function is suitable
to use with List.sort.  I can't figure out how to use it:
# k;;
- : int list = [3; 2; 1]
# List.sort (compare 1 2) k;;
This expression has type int but is here used with type 'a -> 'a ->
# List.sort (+) k;;
- : int list = [1; 2; 3]
# a;;
- : char list = ['d'; 'b'; 'g']
# List.sort (+) a;;
This expression has type char list but is here used with type int list
# List.sort (compare 'a' 'b') a;;
This expression has type int but is here used with type 'a -> 'a ->
# compare 'a' 'b';;
- : int = -1
What is confusing to me is that the manual says:

"Sort a list in increasing order according to a comparison
function. The comparison function must return 0 if it arguments
compare as equal, a positive integer if the first is greater, and a
negative integer if the first is smaller. For example, the compare
function is a suitable comparison function. " 

I could not find a single example on how to use this function in the
manual.  Can somebody show me how to use it please?

Johann Spies          Telefoon: 021-808 4036
Informasietegnologie, Universiteit van Stellenbosch

     "My son, if sinners entice thee, consent thou not." 
                               Proverbs 1:10
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