made the token type less repetitive

src/token/type.hpp

@@ -1,60 +1,50 @@
 #pragma once
 
+#include <array>
 #include <ostream>
+#include <string_view>
 
-enum class TokenType {
-    ILLEGAL,
-    EOF_,
+namespace lexer {
 
-    IDENT,
-    INT,
+// X-macro list of token types and their string representations
+#define TOKEN_LIST                                                             \
+    X(ILLEGAL, "ILLEGAL")                                                      \
+    X(EOF_, "EOF")                                                             \
+    X(IDENT, "IDENT")                                                          \
+    X(INT, "INT")                                                              \
+    X(ASSIGN, "=")                                                             \
+    X(PLUS, "+")                                                               \
+    X(COMMA, ",")                                                              \
+    X(SEMICOLON, ";")                                                          \
+    X(LPAREN, "(")                                                             \
+    X(RPAREN, ")")                                                             \
+    X(LBRACE, "{")                                                             \
+    X(RBRACE, "}")                                                             \
+    X(FUNCTION, "FUNCTION")                                                    \
+    X(LET, "LET")
 
-    ASSIGN,
-    PLUS,
+    // Define the TokenType enum using the X-macro
+    enum class TokenType {
+#define X(name, str) name,
+        TOKEN_LIST
+#undef X
+    };
 
-    COMMA,
-    SEMICOLON,
+    // Array mapping enum values to their string representations
+    static constexpr std::
+        array<std::string_view, static_cast<size_t>(TokenType::LET) + 1>
+            tokenTypeStrings = {
+#define X(name, str) str,
+                TOKEN_LIST
+#undef X
+    };
 
-    LPAREN,
-    RPAREN,
-    LBRACE,
-    RBRACE,
-
-    FUNCTION,
-    LET
-};
-
-inline std::ostream& operator<<(std::ostream& os, TokenType tt) {
-    switch (tt) {
-    case TokenType::ILLEGAL:
-        return os << "ILLEGAL";
-    case TokenType::EOF_:
-        return os << "EOF";
-    case TokenType::IDENT:
-        return os << "IDENT";
-    case TokenType::INT:
-        return os << "INT";
-    case TokenType::ASSIGN:
-        return os << "=";
-    case TokenType::PLUS:
-        return os << "+";
-    case TokenType::COMMA:
-        return os << ",";
-    case TokenType::SEMICOLON:
-        return os << ";";
-    case TokenType::LPAREN:
-        return os << "(";
-    case TokenType::RPAREN:
-        return os << ")";
-    case TokenType::LBRACE:
-        return os << "{";
-    case TokenType::RBRACE:
-        return os << "}";
-    case TokenType::FUNCTION:
-        return os << "FUNCTION";
-    case TokenType::LET:
-        return os << "LET";
-    default:
+    // Stream insertion operator using the lookup array
+    inline std::ostream& operator<<(std::ostream& os, TokenType type) {
+        auto idx = static_cast<size_t>(type);
+        if (idx < tokenTypeStrings.size())
+            return os << tokenTypeStrings[idx];
         return os << "Unknown";
     }
-}
+
+} // namespace lexer