Fix syntax highlighting unicode support (#475)

* convert BasicParser to a template

* fix syntax hightlighting with unicode characters

src/devtools/syntax.hpp

@@ -16,11 +16,11 @@ namespace devtools {
 
     struct Token {
         TokenTag tag;
-        std::string text;
+        std::wstring text;
         Location start;
         Location end;
 
-        Token(TokenTag tag, std::string text, Location start, Location end)
+        Token(TokenTag tag, std::wstring text, Location start, Location end)
             : tag(tag),
               text(std::move(text)),
               start(std::move(start)),

src/devtools/syntax_highlighting.cpp

@@ -56,7 +56,7 @@ static std::unique_ptr<FontStylesScheme> build_styles(
 }
 
 std::unique_ptr<FontStylesScheme> devtools::syntax_highlight(
-    const std::string& lang, std::string_view source
+    const std::string& lang, std::wstring_view source
 ) {
     try {
         if (lang == "lua") {

src/devtools/syntax_highlighting.hpp

@@ -11,6 +11,6 @@ namespace devtools {
     };
 
     std::unique_ptr<FontStylesScheme> syntax_highlight(
-        const std::string& lang, std::string_view source
+        const std::string& lang, std::wstring_view source
     );
 }