From type/Allomorph

See Original text in context

method flip(Allomorph:D:)

Calls Str.flip on the invocant's Str value.

From type/Cool

See Original text in context

sub flip(Cool $s --> Str:D)
method flip()

Coerces the invocant (or in sub form, its argument) to Str, and returns a reversed version.

say 421.flip;       # OUTPUT: «124␤»

From type/Str

See Original text in context

multi sub    flip(Str:D  --> Str:D)
multi method flip(Str:D: --> Str:D)

Returns the string reversed character by character.

Examples:

"Raku".flip;  # OUTPUT: «ukaR» 
"ABBA".flip;  # OUTPUT: «ABBA»