Add custom syntax highlighter and optimize

include/syntax/langs.h

@@ -0,0 +1,28 @@
+#ifndef SYNTAX_LANGS_H
+#define SYNTAX_LANGS_H
+
+#include "syntax/decl.h"
+
+#define DEF_LANG(name)                                                         \
+  std::shared_ptr<void> name##_parse(std::vector<Token> *tokens,               \
+                                     std::shared_ptr<void> in_state,           \
+                                     const char *text, uint32_t len);          \
+  bool name##_state_match(std::shared_ptr<void> state_1,                       \
+                          std::shared_ptr<void> state_2);
+
+#define LANG_A(name) {name##_parse, name##_state_match}
+
+DEF_LANG(ruby);
+
+inline static const std::unordered_map<
+    std::string,
+    std::tuple<std::shared_ptr<void> (*)(std::vector<Token> *tokens,
+                                         std::shared_ptr<void> in_state,
+                                         const char *text, uint32_t len),
+               bool (*)(std::shared_ptr<void> state_1,
+                        std::shared_ptr<void> state_2)>>
+    parsers = {
+        {"ruby", LANG_A(ruby)},
+};
+
+#endif