/* expr-tree.bison */

%token INT
%type Exp
%%
line : expr '\n'      { cout << ($1)->eval(); }
     ;
expr : expr '+' term  { $$ = new PlusExp($1, $3); }
     | term
     ;
term : term '*' fact  { $$ = new TimesExp($1, $3); }
     | fact
     ;
fact : '(' expr ')'   { $$ = $2; }
     | INT            { $$ = new IntegerLiteral($1); }
     ;