Documentation for routine before assembled from the following pages:

Language documentation: Operators §

From Operators

(Operators) infix before §

multi sub infix:<before>(Any,       Any)
multi sub infix:<before>(Real:D,    Real:D)
multi sub infix:<before>(Str:D,     Str:D)
multi sub infix:<before>(Version:D, Version:D)

Generic ordering, uses the same semantics as cmp. Returns True if the first argument is smaller than the second.

Class: StrDistance §

From StrDistance

(StrDistance) method before §

This is actually a class attribute, and called as a method returns the string before the transformation:

say $str-dist.before; # OUTPUT: «fold␤»