The keywords of sketch are picturebox curve
def dots frame global input
line polygon put repeat set
sweep and then. The sketch parser will note a
syntax error if any of these are used in place of a proper identifier.
In addition, there are reserved words
that can currently be defined by the user, but with the risk that
future versions of sketch will reject those definitions. The
reserved words are atan2 cos inverse
perspective project rotate scale
sin special sqrt translate unit and
view.