Fix syntax highlighting unicode support (#475)

* convert BasicParser to a template

* fix syntax hightlighting with unicode characters

src/coders/BasicParser.hpp

@@ -0,0 +1,53 @@
+#pragma once
+
+#include "commons.hpp"
+#include "data/dv.hpp"
+
+template <typename CharT>
+class BasicParser {
+    using StringT = std::basic_string<CharT>;
+    using StringViewT = std::basic_string_view<CharT>;
+protected:
+    std::string_view filename;
+    StringViewT source;
+    uint pos = 0;
+    uint line = 1;
+    uint linestart = 0;
+
+    virtual void skipWhitespace();
+    void skip(size_t n);
+    void skipLine();
+    bool skipTo(const StringT& substring);
+    void expect(CharT expected);
+    void expect(const StringT& substring);
+    bool isNext(const StringT& substring);
+    void expectNewLine();
+    void goBack(size_t count = 1);
+    void reset();
+
+    int64_t parseSimpleInt(int base);
+    dv::value parseNumber(int sign);
+    dv::value parseNumber();
+    StringT parseString(CharT chr, bool closeRequired = true);
+
+    parsing_error error(const std::string& message);
+public:
+    StringViewT readUntil(CharT c);
+    StringViewT readUntil(StringViewT s, bool nothrow);
+    StringViewT readUntilWhitespace();
+    StringViewT readUntilEOL();
+    StringT parseName();
+    StringT parseXmlName();
+    bool hasNext();
+    size_t remain() const;
+    CharT peek();
+    CharT peekInLine();
+    CharT peekNoJump();
+    CharT nextChar();
+
+    BasicParser(std::string_view file, StringViewT source)
+        : filename(file), source(source) {
+    }
+};
+
+#include "BasicParser.inl"