either the $k or the $closure method work
Be careful! Whilst the for my $name... works, it is dangerous:
my @names = qw[ the quick brown fox ]; undef %h; for my $alias ( @names ){ $h{ $alias } = sub { print $alias; $alias = 'fred'; ####### Mysterious action at a distance +here }; }; pp \%h; { brown => sub { "???" }, fox => sub { "???" }, quick => sub { "???" }, the => sub { "???" }, } for my $key ( keys %h ) { $h{ $key }->(); };; the fox brown quick print @names;; fred fred fred fred
With the for my $name ( ... ) method, the closures are and remain aliases to the source list in the for loop; which means that if you assign to the closure within the subroutine, you will cause spooky action at a distance to the content of that source.
And perhaps worse, changes to the source of the for list, will remotely change the contents of the closures:
[0]{} Perl> my @names = qw[ the quick brown fox ]; undef %h; for my $alias ( @names ){ $h{ $alias } = sub { print $alias; }; }; pp \%h; { brown => sub { "???" }, fox => sub { "???" }, quick => sub { "???" }, the => sub { "???" }, } $names[ 1 ] .= 'Mysterious changes'; ###### And again here! for my $key ( keys %h ) { $h{ $key }->(); };; the fox brown quickMysterious changes
In reply to Re^3: naming anonymous subroutines inner variables
by BrowserUk
in thread naming anonymous subroutines inner variables
by writch
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