Re^3: Local for lexicals

[ikegami]

So what you really want are anon subs with named arguments. Have you looked at

• signatures
• Sub::Signatures
• Method::Signatures
• Perl6::Subs
• Perl6::Parameters

use signatures;
my $lamb = sub ($x, $y) { $x + $y };
print( $lamb->(3,4), "\n" );  # 7

Unfortunately, the following doesn't work

use signatures;
my $lamb = sub ($x) { $x = 4 };
my $y = 3;
$lamb->($y);
print("$y\n");  # 3  XXX want 4

I also tried Sub::Signatures and Perl6::Subs. Both accept anonymous subs with named parameters. Neither pass the alias test.

Maybe one of them can be fixed. Maybe it works with one of the other modules.

Update: To spend the least amount of effort, your best bet is to fork signatures. It hooks itself into the parser to change

sub (...) { ... }

into

sub { my (...) = @_; ... }

By changing what gets injected (my (...) = @_;) to something like the following, you can achieve aliasing (which also fixes tied vars):

Lexical::Alias::alias(my $x, $_[0]);
Lexical::Alias::alias(my $y, $_[1]);
Lexical::Alias::alias(my $z, $_[2]);

It might be best to use copying semantics by default, while adding a mechanism to specify aliasing ("is rw"?). That would allow you to extend signatures instead of replacing it.