MINOR: lua: Add tokenize function.

For tokenizing a string, standard Lua recommends to use regexes.
The followinf example splits words:

   for i in string.gmatch(example, "%S+") do
      print(i)
   end

This is a little bit overkill for simply split words. This patch
adds a tokenize function which quick and do not use regexes.

doc/lua-api/index.rst

@@ -645,6 +645,40 @@ Core class
   Match two networks. For example "127.0.0.1/32" matchs "127.0.0.0/8". The order
   of network is not important.
 
+.. js:function:: core.tokenize(str, separators [, noblank])
+
+  **context**: body, init, task, action, sample-fetch, converter
+
+  This function is useful for tokenizing an entry, or splitting some messages.
+  :param string str: The string which will be split.
+  :param string separators: A string containing a list of separators.
+  :param boolean noblank: Ignore empty entries.
+  :returns: an array of string.
+
+  For example:
+
+.. code-block:: lua
+
+	local array = core.tokenize("This function is useful, for tokenizing an entry.", "., ", true)
+	print_r(array)
+..
+
+  Returns this array:
+
+.. code-block:: text
+
+	(table) table: 0x21c01e0 [
+	    1: (string) "This"
+	    2: (string) "function"
+	    3: (string) "is"
+	    4: (string) "useful"
+	    5: (string) "for"
+	    6: (string) "tokenizing"
+	    7: (string) "an"
+	    8: (string) "entry"
+	]
+..
+
 .. _proxy_class:
 
 Proxy class

src/hlua_fcn.c

@@ -915,6 +915,53 @@ int hlua_fcn_post_init(lua_State *L)
 	return 1;
 }
 
+/* This Lua function take a string, a list of separators.
+ * It tokenize the input string using the list of separators
+ * as separator.
+ *
+ * The functionreturns a tablle filled with tokens.
+ */
+int hlua_tokenize(lua_State *L)
+{
+	const char *str;
+	const char *sep;
+	int index;
+	const char *token;
+	const char *p;
+	const char *c;
+	int ignore_empty;
+
+	ignore_empty = 0;
+
+	str = luaL_checkstring(L, 1);
+	sep = luaL_checkstring(L, 2);
+	if (lua_gettop(L) == 3)
+		ignore_empty = hlua_checkboolean(L, 3);
+
+	lua_newtable(L);
+	index = 1;
+	token = str;
+	p = str;
+	while(1) {
+		for (c = sep; *c != '\0'; c++)
+			if (*p == *c)
+				break;
+		if (*p == *c) {
+			if ((!ignore_empty) || (p - token > 0)) {
+				lua_pushlstring(L, token, p - token);
+				lua_rawseti(L, -2, index);
+				index++;
+			}
+			token = p + 1;
+		}
+		if (*p == '\0')
+			break;
+		p++;
+	}
+
+	return 1;
+}
+
 int hlua_parse_addr(lua_State *L)
 {
 	struct hlua_addr *addr;
@@ -1000,6 +1047,7 @@ int hlua_fcn_reg_core_fcn(lua_State *L)
 	hlua_class_function(L, "get_info", hlua_get_info);
 	hlua_class_function(L, "parse_addr", hlua_parse_addr);
 	hlua_class_function(L, "match_addr", hlua_match_addr);
+	hlua_class_function(L, "tokenize", hlua_tokenize);
 
 	/* Create listener object. */
 	lua_newtable(L);