polypompholyx has it right. Some of your confusion may be related to the way that barewords are translated into filenames when Perl looks for a module. For example, 'use Math::Complex;' signals Perl to search for the file 'Math/Complex.pm' in @INC and to load it if found (or die with an error if it can't be found).

But even if the module Math/Complex.pm is found, it may or may not contain the package declaration Math::Complex. For example, it could have a typo:

package Math::Compelx;

# blah, blah, blah

1; # modules need to return 'true'

[download]

Or it could have multiple packages:

package Math::Complex;

# blah, blah, blah

package Math::Complex::Private;

# blah, blah, blah

1; # modules need to return 'true'

[download]

-xdg

Code written by xdg and posted on PerlMonks is public domain. It is provided as is with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.

In reply to Re: What is module? Difference between module and package? by xdg
in thread What is module? Difference between module and package? by shans

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.