It's not like providing (allowing & supporting) "lexically-scoped" subroutines should be so considered so radical -- they are the norm in most languages. Perl, because of it's origins as a scripting language wasn't perceived to need such subtleties as lexical scoping when it was first developed, because it wasn't designed to be a general-purpose high-level compiler-like language.

Certainly not. I'm only aware of Pascal having lexically scoped/nestable subroutines, likely Modula has inherited them. Many other languages only have one, global, namespace for subroutines - certainly, Python, Ruby, PHP, JavaScript, Visual Basic, C and C++ have it that way.

In Perl, what you want is written in the following idiom:

sub foo {
    my $bar = sub {
        print "In bar\n";
    };
    $bar->();
};

[download]

This idiom is frequently used and if somebody cannot read it, they should just learn Perl. You could change into a syntactically different flavour if you're willing to trade lexical for dynamic scope:

sub foo {
    local *bar = sub {
        print "In bar\n";
    };
    bar();
};

[download]

In reply to Re^5: Perl scoping not logical...? by Corion
in thread Perl scoping not logical...? by perl-diddler

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.