I've been staring at this unholy construct $self->{&{\&{$testname}}}->($system); for about 15 minutes, And I still haven't a clue what it's meant to do.

Perhaps you could fill in the blanks?

  1. $testname is a string containing the name of a subroutine?
  2. \&{ $testname }; returns a code reference to the named subroutine.
  3. &{ \&{ $testname } } invokes that coderef. Ie, a long winded and obfuscated way of doing: &$testname
  4. $self->{ &{ \&{ $testname } } } Uses the (if any) return code from the subroutine as a key into the object hash.
  5. $self->{ &{ \&{ $testname } } }->( ... ); who's associated value is another coderef, which it invokes ...
  6. $self->{ &{ \&{ $testname } } }->( $system ); passing one variable $system (which is apparently a hashref.)

Unless you have pre-populated the object hash with a key matching every possible return value from every possible test name, and associated an appropriate coderef for all of those keys; that line isn't trying to do what you think it is. (And even if it is, the way it is written is unnecessarily complicated and obfuscate.)

(And a brief glance at the rest of your code makes me think you're writing code you will not be able to maintain.)

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re: how to call a sub via variable in library by BrowserUk
in thread how to call a sub via variable in library by glenn

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.