Add lua bindings for levenshtein distance

diff --git a/src/lua/lua_util.c b/src/lua/lua_util.c
index b17eef9aee0c2ef5e183763ec7bb9214c8b52836..57b93d12f8f3e5953bf22ca698f3fd74afc013df 100644 (file)
--- a/src/lua/lua_util.c
+++ b/src/lua/lua_util.c
@@ -86,6 +86,15 @@ LUA_FUNCTION_DEF (util, tanh);
  */
 LUA_FUNCTION_DEF (util, parse_html);
 
+/***
+ * @function util.levenshtein_distance(s1, s2)
+ * Returns levenstein distance between two strings
+ * @param {string} s1 the first string
+ * @param {string} s2 the second string
+ * @return {number} number of differences in two strings
+ */
+LUA_FUNCTION_DEF (util, levenshtein_distance);
+
 static const struct luaL_reg utillib_f[] = {
        LUA_INTERFACE_DEF (util, create_event_base),
        LUA_INTERFACE_DEF (util, load_rspamd_config),
@@ -96,6 +105,7 @@ static const struct luaL_reg utillib_f[] = {
        LUA_INTERFACE_DEF (util, tokenize_text),
        LUA_INTERFACE_DEF (util, tanh),
        LUA_INTERFACE_DEF (util, parse_html),
+       LUA_INTERFACE_DEF (util, levenshtein_distance),
        {NULL, NULL}
 };
 
@@ -500,6 +510,25 @@ lua_util_parse_html (lua_State *L)
        return 1;
 }
 
+static gint
+lua_util_levenshtein_distance (lua_State *L)
+{
+       const gchar *s1, *s2;
+       gsize s1len, s2len;
+       gint dist = 0;
+
+       s1 = luaL_checklstring (L, 1, &s1len);
+       s2 = luaL_checklstring (L, 2, &s2len);
+
+       if (s1 && s2) {
+               dist = rspamd_strings_levenshtein_distance (s1, s1len, s2, s2len);
+       }
+
+       lua_pushnumber (L, dist);
+
+       return 1;
+}
+
 static gint
 lua_load_util (lua_State * L)
 {