Re: The sperm secret operator: is it new?

On Wed, Mar 14, 2012 at 7:48 AM, John Douglas Porter
<[email protected]> wrote:
> So is that the Perl 6 smart match operator? or something else?

The latter.

> In any case... How does it work here? =A0It looks like it's functionally
> equivalent to scalar()... but why?

Perl's ~ is operand sensitive; if its operand has a numeric value
(either because it was assigned a number, the result of a numeric
operation,  or had been used in numeric context), it is a numeric
bitwise or (implicitly converting to UV, or under the scope of use
integer, IV, first); otherwise it is a string bitwise or.

For most inputs, in either case it can be repeated to reproduce the
original value and acts just like scalar().

Examples of exceptions:

# floating point

$x =3D 1.23; print ~~$x; # 1

# string used in numeric context

$x =3D "1.23"; print ~~$x if $x !=3D 0; # 1

# integer out of range

use Config '%Config';

$x=3D2**(8*$Config{uvsize}); print ~~$x; # max uv

$x =3D -1; print ~~$x; # max uv

$x =3D 2**(8*$Config{uvsize}-1); use integer; print ~~$x; # min iv

$x =3D -2**(8*$Config{uvsize}-1)-1; use integer; print ~~$x; # min iv