// Pequeno LOGO

// 

// Exemplos

// r45f100r45f100l45f20mb60wf20

{

var resp='<svg height="200" width="400">  <path d="M150 0 '

var x=150;

var y=0;

var dir=0;

var pen="L";

var rest= '" stroke="red" stroke-width="3" fill="none" /> </svg>'; 

}

start = command* {return resp+rest;}

command = forward / backward / right / left / penup / pendown 

forward = "f" n:number 
{

  x=x+n*Math.cos(dir*Math.PI/180); 

  y=y+n*Math.sin(dir*Math.PI/180);

  resp=resp+pen+x+' '+y+' ';

  return "";

}

backward = "b" n:number 

{

  x=x-n*Math.cos(dir*Math.PI/180); 

  y=y-n*Math.sin(dir*Math.PI/180);

  resp=resp+pen+x+' '+y+' ';

  return "";

}

right = "r" n:number {dir=dir+n; return "";}  

left = "l" n:number {dir=dir-n; return "";}  

penup = "m" {pen="M";}

pendown = "w" {pen="L";}

number= digit+ {return parseInt(text());}

identifier = letter char* {return text();}

char=letter/digit

digit=[0-9]

letter=[a-zA-Z]

_ "whitespace"
  = [ \t\n\r]*

nl= [\n] _