"repeat 6 [\n\tmove 100; \n\tturn 30;\n\trepeat 15 [\n\t\tpen red; \n\t\tmove 100; \n\t\tturn 43; \n\t\tpen blue;\n\t\trepeat 20 [\n\t\t\tmove 25; \n\t\t\tturn 13;\n            pen yellow; move 16; pen blue; turn 5;\n\t\t]\n\tpen red;\n\tmove 100;]\n]"

lex tokens:

[CommandName "repeat",Parameter "6",OpenBracket,CommandName "move",Parameter "100",Semicolon,CommandName "turn",Parameter "30",Semicolon,CommandName "repeat",Parameter "15",OpenBracket,CommandName "pen",Parameter "red",Semicolon,CommandName "move",Parameter "100",Semicolon,CommandName "turn",Parameter "43",Semicolon,CommandName "pen",Parameter "blue",Semicolon,CommandName "repeat",Parameter "20",OpenBracket,CommandName "move",Parameter "25",Semicolon,CommandName "turn",Parameter "13",Semicolon,CommandName "pen",Parameter "yellow",Semicolon,CommandName "move",Parameter "16",Semicolon,CommandName "pen",Parameter "blue",Semicolon,CommandName "turn",Parameter "5",Semicolon,CloseBracket,CommandName "pen",Parameter "red",Semicolon,CommandName "move",Parameter "100",Semicolon,CloseBracket,CloseBracket]

parser stack