feat: add 61 lexer

src/yycc/carton/lexer61.hpp

@@ -0,0 +1,46 @@
+#pragma once
+#include "../macro/class_copy_move.hpp"
+#include <expected>
+#include <vector>
+#include <string>
+#include <string_view>
+
+namespace yycc::carton::lexer61 {
+
+    enum class LexerState { Space, Single, Double, Escape, Normal };
+
+    // @brief Any error occurs when lexer working.
+    enum class LexerError {
+        UnexpectedEnd, ///< The end of command line is not expected.
+    };
+
+    template<typename T>
+    using LexerResult = std::expected<T, LexerError>;
+
+    class Lexer61 {
+    public:
+        Lexer61();
+        ~Lexer61();
+        YYCC_DEFAULT_COPY_MOVE(Lexer61)
+
+    public:
+        LexerResult<std::vector<std::u8string_view>> lex(const std::u8string_view& cmd);
+        LexerResult<std::vector<std::u8string>> owend_lex(const std::u8string_view& cmd);
+
+    private:
+        void reset();
+
+        void proc_space();
+        void proc_single();
+        void proc_double();
+        void proc_escape();
+        void proc_normal();
+
+        std::vector<std::u8string_view> m_ArgsCollection; ///< Internal result holder.
+        std::u8string m_CurrentArg;                   ///< Holding current building commandline argument.
+        char8_t m_CurrentChar;                    ///< Holding current char analysing.
+        LexerState m_State;                       ///< Recording current state.
+        LexerState m_PrevState;                   ///< Recording previous state.
+    };
+
+} // namespace yycc::carton::lexer61