add flex lexer

src/lexer/lex.l

@@ -0,0 +1,47 @@
+%{
+#include "token.h"
+int current_line = 1;
+int current_column = 1;
+
+int yywrap() {
+    return 1;
+}
+%}
+
+%%
+
+\"(\\[a-z\"'`]|[^\\"])*\" {
+    add_token(TOKEN_STRING, yytext, current_line, current_column);
+    current_column += yyleng;
+}
+
+[0-9]+ {
+    add_token(TOKEN_NUMBER, yytext, current_line, current_column);
+    current_column += yyleng;
+}
+
+[a-zA-Z_][a-zA-Z0-9_]* {
+    add_token(TOKEN_IDENTIFIER, yytext, current_line, current_column);
+    current_column += yyleng;
+}
+
+"." {
+    add_token(TOKEN_DOT, yytext, current_line, current_column);
+    current_column += yyleng;
+}
+
+\n {
+    add_token(TOKEN_NEW_LINE, yytext, current_line, current_column);
+    current_line++;
+    current_column = 1;
+}
+
+[ \t]+ {
+    current_column += yyleng;  // Advance column for whitespace
+}
+
+.   { 
+    fprintf(stderr, "Error: Unexpected character '%c' at line %d\n", *yytext, yylineno);
+    exit(1);
+}
+%%