Dual value floating-point number and string
class NumStr is Allomorph is Num { }
NumStr is a dual value type, a subclass of both Allomorph, hence Str, and Num.
See Allomorph for further details.
my $num-str = <42.1e0>;
say $num-str.^name; # OUTPUT: «NumStr»
my Num $num = $num-str; # OK!
my Str $str = $num-str; # OK!
# ∈ operator cares about object identity
say 42e10 ∈ <42e10 55 1>; # OUTPUT: «False»
method new(Num $i, Str $s)
The constructor requires both the Num and the Str value, when constructing one directly the values can be whatever is required:
my $f = NumStr.new(42.1e0, "forty two and a bit");
say +$f; # OUTPUT: «42.1»
say ~$f; # OUTPUT: «"forty two and a bit"»
method Num
Returns the Num value of the NumStr.
multi method Numeric(NumStr:D: --> Num:D)
multi method Numeric(NumStr:U: --> Num:D)
The :D variant returns the numeric portion of the invocant. The :U variant issues a warning about using an uninitialized value in numeric context and then returns value 0e0.
multi method Real(NumStr:D: --> Num:D)
multi method Real(NumStr:U: --> Num:D)
The :D variant returns the numeric portion of the invocant. The :U variant issues a warning about using an uninitialized value in numeric context and then returns value 0e0.
multi infix:<===>(NumStr:D $a, NumStr:D $b)
NumStr Value identity operator. Returns True if the Num values of $a and $b are identical and their Str values are also identical. Returns False otherwise.