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Here’s a quick way to create an attribute that coerces to an integer from any other number:
package Local::Eg3; use Moose; use Types::Standard -types; has foo => ( is => "ro", isa => Int->plus_coercions( Num, sub{int($_)} ), coerce => 1, ); __PACKAGE__->meta->make_immutable;
You can express the coercion as a string of Perl code, which will in some circumstances help Type::Tiny optimize things.
has foo => ( is => "ro", isa => Int->plus_coercions( Num, 'int($_)' ), coerce => 1, );
Caveats
Don’t forget the coerce => 1 bit. It’s very easy to forget.
If you’re supplying multiple coercions, it might seem clearer to use a fat comma:
Int->plus_coercions( Num => sub { int($_) }, ArrayRef => sub { scalar(@$_) }, Undef => sub { 0 }, )
This will not work because of the auto-quoting powers of =>. Take a look at the winking fat comma in perlsecret though.
