improve string.lastof

1 files changed, 90 insertions, 0 deletions

diff --git a/core/src/xmake/string/lastof.c b/core/src/xmake/string/lastof.c
new file mode 100644
index 000000000..2be44ba22
--- /dev/null
+++ b/core/src/xmake/string/lastof.c
@@ -0,0 +1,90 @@
+/*!A cross-platform build utility based on Lua
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright (C) 2015-2020, TBOOX Open Source Group.
+ *
+ * @author      ruki
+ * @file        lastof.c
+ *
+ */
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * trace
+ */
+#define TB_TRACE_MODULE_NAME                "string_lastof"
+#define TB_TRACE_MODULE_DEBUG               (0)
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * includes
+ */
+#include "prefix.h"
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * private implementation
+ */
+static tb_void_t xm_string_lastof_str(lua_State* lua, tb_char_t const* cstr, tb_size_t nstr, tb_char_t const* csubstr, tb_size_t nsubstr)
+{
+    // find it
+    tb_char_t const* curr = tb_null;
+    tb_char_t const* next = cstr;
+    do
+    {
+        next = tb_strstr(next, csubstr); // faster than tb_strnstr()
+        if (next)
+        {
+            curr = next;
+            next += nsubstr;
+        }
+
+    } while (!next);
+
+    // found?
+    if (curr) lua_pushinteger(lua, curr - cstr + 1);
+    else lua_pushnil(lua);
+}
+static tb_void_t xm_string_lastof_chr(lua_State* lua, tb_char_t const* cstr, tb_size_t nstr, tb_char_t ch)
+{
+    tb_char_t const* pos = tb_strrchr(cstr, ch); // faster than tb_strnrchr()
+    if (pos) lua_pushinteger(lua, pos - cstr + 1);
+    else lua_pushnil(lua);
+}
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * implementation
+ */
+
+/* lastof string (only support plain text)
+ *
+ * @param str             the string
+ * @param substr          the substring
+ */
+tb_int_t xm_string_lastof(lua_State* lua)
+{
+    // check
+    tb_assert_and_check_return_val(lua, 0);
+
+    // get string
+    size_t           nstr = 0;
+    tb_char_t const* cstr = luaL_checklstring(lua, 1, &nstr);
+
+    // get substring
+    size_t           nsubstr = 0;
+    tb_char_t const* csubstr = luaL_checklstring(lua, 2, &nsubstr);
+
+    // lastof it
+    lua_newtable(lua);
+    if (nsubstr == 1) xm_string_lastof_chr(lua, cstr, (tb_size_t)nstr, csubstr[0]);
+    else xm_string_lastof_str(lua, cstr, (tb_size_t)nstr, csubstr, nsubstr);
+    return 1;
+}