Grammar polygones;
Lexer
  num = ('0'..'9')+;
  blank = ' ' | #9 | #10 | #13;

Parser
  Ignored blank;
  polygone = '(' (point Separator ',')* ')' ;
  point =
    {cart:} '(' num 'x' ',' num 'y' ')' |
    {pol:} '(' num ',' num 'deg' ')' ;