add gui.escape_markup

doc/en/scripting/builtins/libgui.md

@@ -50,3 +50,14 @@ gui.clear_markup(
 ```
 
 Removes markup from text.
+
+```lua
+gui.escape_markup(
+    -- markup language ("md" - Markdown)
+    language: str,
+    -- text with markup
+    text: str
+) -> str
+```
+
+Escapes markup in text.

doc/ru/scripting/builtins/libgui.md

@@ -47,3 +47,14 @@ gui.clear_markup(
 ```
 
 Удаляет разметку из текста.
+
+```lua
+gui.escape_markup(
+    -- язык разметки ("md" - Markdown)
+    language: str, 
+    -- текст с разметкой
+    text: str
+) -> str
+```
+
+Экранирует разметку в тексте.

src/graphics/ui/markdown.cpp

@@ -1,7 +1,5 @@
 #include "markdown.hpp"
 
-#include <sstream>
-
 #include "graphics/core/Font.hpp"
 
 using namespace markdown;
@@ -66,6 +64,7 @@ Result<CharT> process_markdown(
                         pos++;
                         continue;
                 }
+                pos--;
             }
         } else if (first == '*') {
             if (pos + 1 < source.size() && source[pos+1] == '*') {

src/graphics/ui/markdown.hpp

@@ -2,6 +2,7 @@
 
 #include <string>
 #include <memory>
+#include <sstream>
 
 struct FontStylesScheme;
 
@@ -19,4 +20,24 @@ namespace markdown {
 
     Result<char> process(std::string_view source, bool eraseMarkdown);
     Result<wchar_t> process(std::wstring_view source, bool eraseMarkdown);
+
+    template <typename CharT>
+    inline std::basic_string<CharT> escape(std::string_view source) {
+        std::basic_stringstream<CharT> ss;
+        int pos = 0;
+        while (pos < source.size()) {
+            CharT first = source[pos];
+            if (first == '\\' && pos + 1 < source.size()) {
+                CharT second = source[++pos];
+                ss << first << second;
+                pos++;
+                continue;
+            } else if (first == '*' || first == '~' || first == '_') {
+                ss << '\\';
+            }
+            ss << first;
+            pos++;
+        }
+        return ss.str();
+    }
 }

src/logic/scripting/lua/libs/libgui.cpp

@@ -738,6 +738,15 @@ static int l_gui_clear_markup(lua::State* L) {
     return lua::pushstring(L, text);
 }
 
+static int l_gui_escape_markup(lua::State* L) {
+    auto lang = lua::require_string(L, 1);
+    std::string text = lua::require_string(L, 2);
+    if (std::strcmp(lang, "md") == 0) {
+        text = std::move(markdown::escape<char>(text));
+    }
+    return lua::pushstring(L, text);
+}
+
 const luaL_Reg guilib[] = {
     {"get_viewport", lua::wrap<l_gui_getviewport>},
     {"getattr", lua::wrap<l_gui_getattr>},
@@ -746,5 +755,7 @@ const luaL_Reg guilib[] = {
     {"str", lua::wrap<l_gui_str>},
     {"get_locales_info", lua::wrap<l_gui_get_locales_info>},
     {"clear_markup", lua::wrap<l_gui_clear_markup>},
+    {"escape_markup", lua::wrap<l_gui_escape_markup>},
     {"__reindex", lua::wrap<l_gui_reindex>},
-    {NULL, NULL}};
+    {NULL, NULL}
+};