config: use defined-or (//) in a few places

Just some golfing to reduce scrolling and hopefully readability.

diff --git a/lib/PublicInbox/Config.pm b/lib/PublicInbox/Config.pm
index f9184bd2872061411c7043592772da778a130346..ae9ad8deef9e910bd89c35388278522b388e47aa 100644 (file)
--- a/lib/PublicInbox/Config.pm
+++ b/lib/PublicInbox/Config.pm
@@ -19,7 +19,7 @@ sub _array ($) { ref($_[0]) eq 'ARRAY' ? $_[0] : [ $_[0] ] }
 # if keys may be multi-value, the value is an array ref containing all values
 sub new {
        my ($class, $file) = @_;
-       $file = default_file() unless defined($file);
+       $file //= default_file();
        my $self;
        if (ref($file) eq 'SCALAR') { # used by some tests
                open my $fh, '<', $file or die;  # PerlIO::scalar
@@ -136,9 +136,7 @@ sub limiter {
 sub config_dir { $ENV{PI_DIR} // "$ENV{HOME}/.public-inbox" }
 
 sub default_file {
-       my $f = $ENV{PI_CONFIG};
-       return $f if defined $f;
-       config_dir() . '/config';
+       $ENV{PI_CONFIG} // (config_dir() . '/config');
 }
 
 sub config_fh_parse ($$$) {