line    :   push identifier ent                 {pushStack($2);}
        |   line push identifier ent            {pushStack($3);}
        |   pop identifier ent                  {popStack($2);}
        |   line pop identifier ent             {popStack($3);}
        |   exit_command ent                    {exit(EXIT_SUCCESS);}
        |   show identifier ent                 {showVal($2);}
        |   line show identifier ent            {showVal($3);}
        |   load identifier identifier ent      {loadVal($2,$3);}
        |   line load identifier identifier ent {loadVal($3,$4);}
        |   line exit_command ent               {exit(EXIT_SUCCESS);}
        |   line exp ent                        {$$ = $2; getError($$);}
        |   exp ent                             {$$ = $1; getError($$);}
        |   '-' '-' exp ent                     {printf("ERROR !\n");}
        |   line '-' '-' exp ent                {printf("ERROR !\n");}
        ;

exp     :   term            {$$ = $1;}
        |   '+' exp         {checkError();}
        |   '*' exp         {checkError();}
        |   '/' exp         {checkError();}
        |   exp and exp     {$$ = $1 & $3;}
        |   exp or exp      {$$ = $1 | $3;}
        |   exp '+' exp     {$$ = $1 + $3;}
        |   exp '-' exp     {$$ = $1 - $3;}
        |   exp '*' exp     {$$ = $1 * $3;}
        |   exp '/' exp     {$$ = $1 / $3;}
        |   exp '\\' exp    {$$ = $1 % $3;}
        |   exp '^' exp     {$$ = pow($1,$3);}
        |   '-' exp         {$$ = $2*-1;}
        |   not exp         {$$ = !$2;}
        |   '(' exp ')'     {$$ = $2;}
        ;

term    :   number      {$$ = $1;}
        |   identifier  {$$ = symbolVal($1);}
        ;