Re: Sequential defined-or operators

While you remain pre-5.10, you might like this technique:

use List::Util qw( first );
my $theme = first { defined $_ } (
    $global_config->{modes}{$current_mode}{theme},
    $theme_config->{current_theme},
    $default_theme,
    'none',
);
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Comment on Re: Sequential defined-or operators Download Code

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Re^2: Sequential defined-or operators by plobsing (Friar) on Jan 15, 2008 at 02:39 UTC
Thats all fine and good until your default value is `ask_user()`. Then this fails due to eager evaluation. `//` fixes this fortunately.	[reply] [d/l] [select]
Re^3: Sequential defined-or operators by ikegami (Patriarch) on Jan 15, 2008 at 03:28 UTC
It took me a second to understand that you are referring to the short-circuiting nature of `//`. If you needed the short-circuiting behaviour pre-5.10, here's one solution: `sub first(&@) { my $cb = shift(@_); for (@_) { my $i = ref eq 'CODE' ? $_->() : $$_; my $rv; $rv = $cb->() for $i; return $i if $rv; } return; } my $theme = first { defined } \$global_config->{modes}{$current_mode}{theme}, \$theme_config->{current_theme}, \&ask_user, \'none';` [download]	[reply] [d/l] [select]