[ocaml-extlib] r427 committed - speed up String.nsplit (linear memory usage) (Closes issue 17)

[codesite...@google.com]

Revision: 427
Author: ygrekheretix
Date: Wed Nov 13 10:26:24 2013 UTC
Log: speed up String.nsplit (linear memory usage) (Closes issue 17)

http://code.google.com/p/ocaml-extlib/source/detail?r=427

Modified:
/trunk/extlib/extString.ml

=======================================
--- /trunk/extlib/extString.ml Wed May 8 17:27:54 2013 UTC
+++ /trunk/extlib/extString.ml Wed Nov 13 10:26:24 2013 UTC
@@ -101,18 +101,17 @@
sub str 0 p, sub str (p + len) (slen - p - len)

let nsplit str sep =
- if str = "" then []
- else if sep = "" then raise Invalid_string
- else (
- let rec nsplit str sep =
- try
- let s1 , s2 = split str sep in
- s1 :: nsplit s2 sep
- with
- Invalid_string -> [str]
+ if str = "" then []
+ else if sep = "" then raise Invalid_string
+ else
+ let rec loop acc pos =
+ if pos > String.length str then
+ List.rev acc
+ else
+ let i = try find_from str pos sep with Invalid_string ->
String.length str in
+ loop (String.sub str pos (i - pos) :: acc) (i + String.length sep)
in
- nsplit str sep
- )
+ loop [] 0

let join = concat