add utf8.sub and lastof

5 files changed, 203 insertions, 0 deletions

diff --git a/core/src/xmake/engine.c b/core/src/xmake/engine.c
index ff7c79061..098a808c8 100644
--- a/core/src/xmake/engine.c
+++ b/core/src/xmake/engine.c
@@ -285,6 +285,8 @@ tb_int_t xm_utf8_char(lua_State *lua);
 tb_int_t xm_utf8_codepoint(lua_State *lua);
 tb_int_t xm_utf8_offset(lua_State *lua);
 tb_int_t xm_utf8_codes(lua_State *lua);
+tb_int_t xm_utf8_sub(lua_State *lua);
+tb_int_t xm_utf8_lastof(lua_State *lua);
 
 // the string functions
 tb_int_t xm_string_trim(lua_State *lua);
@@ -597,6 +599,8 @@ static luaL_Reg const g_utf8_functions[] = {
     {"codepoint", xm_utf8_codepoint},
     {"len", xm_utf8_len},
     {"offset", xm_utf8_offset},
+    {"sub", xm_utf8_sub},
+    {"lastof", xm_utf8_lastof},
     {tb_null, tb_null}
 };
 
diff --git a/core/src/xmake/utf8/lastof.c b/core/src/xmake/utf8/lastof.c
new file mode 100644
index 000000000..8c5ec7dd3
--- /dev/null
+++ b/core/src/xmake/utf8/lastof.c
@@ -0,0 +1,65 @@
+/*!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-present, Xmake Open Source Community.
+ *
+ * @author      ruki
+ * @file        lastof.c
+ *
+ */
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * includes
+ */
+#include "utf8.h"
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * implementation
+ */
+
+/* utf8.lastof(s, substr)
+ */
+tb_int_t xm_utf8_lastof(lua_State *lua) {
+    size_t len;
+    tb_char_t const* s = luaL_checklstring(lua, 1, &len);
+    size_t sublen;
+    tb_char_t const* sub = luaL_checklstring(lua, 2, &sublen);
+
+    if (sublen == 0) {
+        lua_pushnil(lua);
+        return 1;
+    }
+
+    tb_char_t const* p = s;
+    tb_char_t const* last = tb_null;
+    
+    while (1) {
+        p = tb_strstr(p, sub);
+        if (!p) break;
+        last = p;
+        p += 1; 
+    }
+
+    if (last) {
+        tb_long_t count = xm_utf8_len_impl(s, len, 1, last - s, tb_true, tb_null);
+        if (count < 0) {
+             lua_pushnil(lua);
+             return 1;
+        }
+        lua_pushinteger(lua, count + 1);
+    } else {
+        lua_pushnil(lua);
+    }
+    return 1;
+}
diff --git a/core/src/xmake/utf8/sub.c b/core/src/xmake/utf8/sub.c
new file mode 100644
index 000000000..c86c60f22
--- /dev/null
+++ b/core/src/xmake/utf8/sub.c
@@ -0,0 +1,88 @@
+/*!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-present, Xmake Open Source Community.
+ *
+ * @author      ruki
+ * @file        sub.c
+ *
+ */
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * includes
+ */
+#include "utf8.h"
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * implementation
+ */
+
+/* utf8.sub(s, i [, j])
+ */
+tb_int_t xm_utf8_sub(lua_State *lua) {
+    size_t len;
+    tb_char_t const* s = luaL_checklstring(lua, 1, &len);
+    lua_Integer i = luaL_checkinteger(lua, 2);
+    lua_Integer j = luaL_optinteger(lua, 3, -1);
+
+    // map i (char index) to byte offset
+    tb_long_t start_byte = 0;
+    if (i > 0) {
+        start_byte = xm_utf8_offset_impl(s, len, i, 1);
+    } else if (i < 0) {
+        start_byte = xm_utf8_offset_impl(s, len, i, len + 1);
+    } else {
+        start_byte = 1;
+    }
+
+    if (start_byte == -1) {
+        if (i > 0) {
+            lua_pushliteral(lua, "");
+            return 1;
+        } else {
+            start_byte = 1;
+        }
+    } else if (start_byte == 0) {
+        if (i < 0) {
+            start_byte = 1;
+        } else {
+            lua_pushliteral(lua, "");
+            return 1;
+        }
+    }
+
+    // map j (char index) to byte offset (end)
+    tb_long_t end_byte = 0;
+    if (j >= 0) {
+        end_byte = xm_utf8_offset_impl(s, len, j + 1, 1);
+    } else {
+        end_byte = xm_utf8_offset_impl(s, len, j + 1, len + 1);
+    }
+
+    if (end_byte == -1) {
+        if (j >= 0) end_byte = len + 1;
+        else end_byte = 1;
+    } else if (end_byte == 0) {
+         if (j >= 0) end_byte = len + 1;
+         else end_byte = 1;
+    }
+
+    if (end_byte <= start_byte) {
+        lua_pushliteral(lua, "");
+        return 1;
+    }
+
+    lua_pushlstring(lua, s + start_byte - 1, end_byte - start_byte);
+    return 1;
+}
diff --git a/tests/modules/utf8/test.lua b/tests/modules/utf8/test.lua
index f342c8402..51da441d9 100644
--- a/tests/modules/utf8/test.lua
+++ b/tests/modules/utf8/test.lua
@@ -62,3 +62,47 @@ end
 function test_charpattern(t)
     t:require(utf8.charpattern)
 end
+
+function test_sub(t)
+    t:are_equal(utf8.sub("ABC", 1, 1), "A")
+    t:are_equal(utf8.sub("ABC", 2, 2), "B")
+    t:are_equal(utf8.sub("ABC", 1, 2), "AB")
+    t:are_equal(utf8.sub("你好", 1, 1), "你")
+    t:are_equal(utf8.sub("你好", 2, 2), "好")
+    t:are_equal(utf8.sub("你好", 1, 2), "你好")
+    
+    -- mixed
+    t:are_equal(utf8.sub("A你好B", 2, 3), "你好")
+    t:are_equal(utf8.sub("A你好B", 1, 3), "A你好")
+    t:are_equal(utf8.sub("A你好B", 2, 4), "你好B")
+
+    -- negative
+    t:are_equal(utf8.sub("ABC", -1), "C")
+    t:are_equal(utf8.sub("ABC", -2), "BC")
+    t:are_equal(utf8.sub("你好", -1), "好")
+    t:are_equal(utf8.sub("你好", -2), "你好")
+    t:are_equal(utf8.sub("你好", 1, -1), "你好")
+    t:are_equal(utf8.sub("你好", 1, -2), "你")
+
+    -- out of bounds
+    t:are_equal(utf8.sub("ABC", 4), "")
+    t:are_equal(utf8.sub("ABC", 1, 5), "ABC")
+    t:are_equal(utf8.sub("ABC", 0), "ABC")
+    t:are_equal(utf8.sub("ABC", -10), "ABC")
+end
+
+function test_lastof(t)
+    t:are_equal(utf8.lastof("ABC", "A"), 1)
+    t:are_equal(utf8.lastof("ABC", "B"), 2)
+    t:are_equal(utf8.lastof("ABC", "C"), 3)
+    t:are_equal(utf8.lastof("ABCA", "A"), 4)
+
+    t:are_equal(utf8.lastof("你好", "你"), 1)
+    t:are_equal(utf8.lastof("你好", "好"), 2)
+    t:are_equal(utf8.lastof("你好你", "你"), 3)
+
+    t:are_equal(utf8.lastof("A你好A", "A"), 4)
+    t:are_equal(utf8.lastof("A你好A", "好"), 3)
+
+    t:are_equal(utf8.lastof("ABC", "D"), nil)
+end
diff --git a/xmake/core/base/utf8.lua b/xmake/core/base/utf8.lua
index 1a1edc0ea..7351475f8 100644
--- a/xmake/core/base/utf8.lua
+++ b/xmake/core/base/utf8.lua
@@ -29,6 +29,8 @@ local utf8 = utf8 or {}
 -- @interface   utf8.codepoint(s [, i [, j]])
 -- @interface   utf8.offset(s, n [, i])
 -- @interface   utf8.codes(s [, lax])
+-- @interface   utf8.sub(s, i [, j])
+-- @interface   utf8.lastof(s, substr)
 --
 
 -- the char pattern