This slang allows you to put whitespace between the name of a subroutine and the opening parenthesis.
Be aware that this introduces ambiguous situations, like when you want to pass a Parcel to a sub, or
when you need parens around the condition after the keywords if, while and so on...
foo 3, 5; # 15, as usual
foo(3, 5); # also 15, as usual
foo (3, 5); # 15, /o\
# It also allows to put space before argument lists in method calls:
42.fmt('-%d-'); # -42-
42.fmt: '-%d-'; # -42-
42.fmt ('-%d-'); # -42-