set basic repo structure

grammar/MXLexer.g4

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+lexer grammar MXLexer;
+
+// Keywords
+INT: 'int';
+VOID: 'void';
+IF: 'if';
+ELSE: 'else';
+RETURN: 'return';
+
+// Operators
+PLUS: '+';
+MINUS: '-';
+MULTIPLY: '*';
+DIVIDE: '/';
+ASSIGN: '=';
+
+// Punctuation
+LPAREN: '(';
+RPAREN: ')';
+LBRACE: '{';
+RBRACE: '}';
+SEMICOLON: ';';
+
+// Identifiers
+ID: [a-zA-Z_][a-zA-Z_0-9]*;
+
+// Literals
+INT_LITERAL: [0-9]+;
+
+// Whitespace and comments
+WS: [ \t\r\n]+ -> skip;
+COMMENT: '//' ~[\r\n]* -> skip;