output=""
return_code=0
grammar='embedded_actions.y'
lookuptable=[
('n','NUMBER'),
('l','LPAREN'),
('r','RPAREN'),
('p','PLUS'),
('t','TIMES'),
('m','MINUS'),
('d','DIVIDE'),
]
testdrives=[
('',False),
('n',True,"number expression"),
('npn',True,"number number plus expression"),
('ntn',True,"number number times expression"),
('ndn',True,"number number divide expression"),
('nmn',True,"number number minus expression"),
('lnmnr',True,"number number minus parens expression"),
('lnpnrtn',True,"number number plus parens number times expression"),
]

// Set the token type to be of type int
/* This is expression which we are trying to evaluate.
 * Nonterminals start with a lowercase letter and are
 * written conventionaly all lowercase.
 * Each production stops with a dot.
 * After each production there may be an embedded block
 * of C Code, which will be executed once the expression
 * was red.
 */
%include {void append_string(const char*);}
start::= expr. {append_string( "expression "); }

// Note how we can assign letters like A,B and C
// for the values of expressions and use them in C code.
expr ::= expr PLUS expr. { append_string( "plus "); }
expr ::= expr TIMES expr.{ append_string( "times "); }
expr::= expr MINUS expr.{ append_string( "minus "); }
expr::= expr DIVIDE expr.{ append_string( "divide "); }
// Terminals all start with an uppercase first letter and usually
// are written all upercase.
expr ::= LPAREN expr RPAREN.{ append_string( "parens "); }
expr ::= NUMBER.{append_string( "number "); }

// This makes the operators left associative.
%left PLUS MINUS.
// The order is important: TIMES and DIVIDE get higher precedence than PLUS MINUS,
// because they are below.
%left TIMES DIVIDE.