[Ocaml-lib-devel] String.nsplit empty string

[Richard J. <ri...@an...>]

Currently, String.nsplit "" _ returns a single element list:

$ ocaml -I +extlib
        Objective Caml version 3.08.3

# #load "unix.cma";;
# #load "extLib.cma";;
# open ExtString;;
# String.nsplit "" ",";;
- : string list = [""]
# String.nsplit "execute" ",";;
- : string list = ["execute"]

I would argue, however, that it'd be much better if it acted like
Perl's split and this was special-cased to return a zero-length list:

$ perl -MData::Dumper -e 'print (Dumper (split /,/, ""))'
$ perl -MData::Dumper -e 'print (Dumper (split /,/, "execute"))'
--> $VAR1 = 'execute';
$ perl -MData::Dumper -e 'print (Dumper (split /,/, "execute,him"))'
--> $VAR1 = 'execute';
    $VAR2 = 'him';

The reason is that otherwise you need a special case when dealing with
lists of flags, for example:

let f ?(flags = "") () =
  let flags = String.nsplit flags "," in
  (* following doesn't work because if there are no flags, the
   * inner function is called once with a "" argument
   *)
  List.iter (
    fun flag ->
      (* handle it *)
  ) flags;

Rich.

-- 
Richard Jones, CTO Merjis Ltd.
Merjis - web marketing and technology - http://merjis.com
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