FILE <- TOKEN (_ TOKEN)* _*
TOKEN <- (HELLO / WORLD / SMILEY / ESCAPES) { PRINT($0); }
HELLO <- "Hello"
WORLD <- 'world'
SMILEY <- "😊"
ESCAPES <- '\\\'\"\a\b\f\t\v\x3d\u20AC'
_ <- ' ' / '\r\n' / '\n'
