StrDistance objects are used to represent the return of the string transformation operator.

say (($ = "fold") ~~ tr/old/new/).^name;  # OUTPUT: «StrDistance␤»

A StrDistance object will stringify to the resulting string after the transformation, and will numify to the distance between the two strings.

my $str = "fold";
my $str-dist = ($str ~~ tr/old/new/);
say ~$str-dist;  # OUTPUT: «fnew␤» 
say +$str-dist;  # OUTPUT: «3␤» 

Methods

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␤» 

method after

Also a class attribute, returns the string after the transformation:

say $str-dist.after;  # OUTPUT: «fnew␤» 

method Bool

Returns True if before is different from after.

method Numeric

Returns the distance as a number.

method Int

multi method Int(StrDistance:D:)

Returns the distance between the string before and after the transformation.

method Str

multi method Str(StrDistance:D: --> Str)

Returns an after string value.

my $str-dist = ($str ~~ tr/old/new/);
say $str-dist.Str; # OUTPUT: «fnew␤» 
say ~$str-dist;    # OUTPUT: «fnew␤»