Beefy Boxes and Bandwidth Generously Provided by pair Networks
Welcome to the Monastery

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??
* The reasoning behind sub NAME { } constructs being realized early is so that you can call subroutines even if their definition is "later" in the code.

That's mostly true, but not very precise.

If a subroutine is defined after it is called, the call has to use parenthesis. If it doesn't, it's interpreted as a string literal (or as an error if strict subs are in effect).

$ perl -E 'say 1, foo; sub foo { 3 }' 1foo $ perl -E 'sub foo { 3 }; say 1, foo' 13 $ perl -E 'say 1, foo(); sub foo { 3 }' 13

However it the call uses parenthesis, there's no need it has to be know at compile time at all:

$ perl -E 'eval "sub foo { 3 }"; say 1, foo();' 13

But I think for this discussion it's more important to ask when the lexical pad of sub a is being built and destroyed. As long as the a is not part of the call chain, $x is in no lex pad, and sub b can't work in a meaningful way.

Perl 6 - links to (nearly) everything that is Perl 6.

In reply to Re^3: Defining a sub within a sub: OK? by moritz
in thread Defining a sub within a sub: OK? by talexb

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

  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?

What's my password?
Create A New User
Domain Nodelet?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others scrutinizing the Monastery: (4)
As of 2024-04-24 02:52 GMT
Find Nodes?
    Voting Booth?

    No recent polls found