So I was thinking about what BrowserUK said. "Misguided attempts to gloss over moderately 'difficult' Perl syntax..." It appears to me he's absolutely right. So I went ahead and rewrote some of the examples from the book. 
sub upto_list {
    my    $from = shift;
    state $upto = shift;
    return undef if $from > $upto;
    return {
        head => $from,
        tail => sub {
            upto_list( $from + 1 );
            },
    };
}

sub show {
    my $node = shift;
    my $i    = shift // 10;
    while ($node->{head} && $i-- > 0) {
        say $node->{head};
        $node = $node->{tail}->();
    }
}

show( upto_list( 10, 15 ) );

[download]
I personally think that that is much easier to understand than the Lisp-like version from the book... It even works faster. What's the point in making Perl look like Lisp anyway? So! I'll answer my own question. 'Anonimous Monk, just rewrite the whole damn chapter in Perl'. Thanks everyone! Especially BrowserUK.

In reply to Re: How to understand chapter 6 of Higher Order Perl? by Anonymous Monk
in thread How to understand chapter 6 of Higher Order Perl? by Anonymous Monk

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