• program: "sub", "main", "(", ")", {statement, "\n"}, "end", "sub";

• statement: (assingment | print | declare | while | if_else);

• assingment: identifier, "=", rel_expression;

• print: "print", rel_expression;

• declare: "dim", identifier, "as", type;

• while: "while", rel_expression, {statement, "\n"}, "wend";

• if_else: "if", rel_expression, "then", {statement, "\n"}, ["else", "\n", {statement, "\n"}], "end", "if";

• rel_expression: expression, (("=" | ">" | "<"), expression);

• expression: term, {("+" | "-" | "or"), term};

• term: factor, {("*" | "/" | "and"), factor};

• factor: number, ("True" | "False"), (“+” | “-” | "not"), identifier | "(", rel_expression, ")" | "input");

• type: "integer" | "boolean"

• identifier = letter, { letter | digit | “_” } ;

• number = digit, { digit } ;

• letter = "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L" | "M" | "N" | "O" | "P" | "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z" ;

• digit = ( "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ) ;

Para utilizar o compilador, rode o arquivo main.py, passando como argumento o arquivo *.vbs a ser compilado. Para testar com o arquivo de teste:

$ python main.py test_file.vbs