Re^2: Read File In Four-Line Chunks / TMTOWTDI / Golf (more)

[Aristotle]

Some further perversions of the LISPish way:

#!/usr/bin/perl -w
use strict;

open my $fh, '<', 'details.txt' or die $!;

my $read_lines;

while(
    my @details = ($read_lines = sub {
        my $amnt = shift;
        return unless defined(my $line = <$fh>);
        return (
            $line,
            $amnt > 1 ? $read_lines->($amnt - 1) : ()
        );
    })->(4)
) {
    print @details, "\n";
}

Refined perversion:

#!/usr/bin/perl -w
use strict;

sub make_read_lines {
    my ($fh, $lines) = @_;
    return $lines == 1
        ? sub { return unless defined(my $line = <$fh>); $line }
        : do {
            my $next_lines = make_read_lines($fh, $lines - 1);
            sub {
                return unless defined(my $line = <$fh>);
                $line, $next_lines->()
            };
        };
}

open my $fh, '<', 'details.txt' or die $!;

my $read_4_lines = make_read_lines($fh, 4);

while(my @details = $read_4_lines->()) {
    print @details, "\n";
}

Makeshifts last the longest.