Re: function encapsulation

A few points:

If you use use, the file has to have a .pm extension, even if it does not have any package definitions. On the other hand, require can take any arbitrary filename as an argument, so you could do:
```
require 'file.pl';
[download]
```
if you want, whereas with use the file needs to be called "file.pm".
In both cases (use and require), you do not need the filename::function syntax you mentioned if the file does not contain any package declarations and just has the function definitions. The functions are imported into your current namespace.
In both cases the included file has to return a true value. This is usually accomplished by putting a line containing "1;" at the end of the file.

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RE: Re: function encapsulation by maverick (Curate) on Jul 13, 2000 at 19:35 UTC
more points: 'use' happens when the script is compiled 'require' happens as the script runs So, if you make any changes to @INC, it won't effect any of the 'use' statements, but it will the 'require's. Also, if you 'perl -c' the script, the '.pm's that were 'use'd in will be checked for sytax, the ones that were 'require'd in won't be. /\/\averick	[reply]
RE: RE: Re: function encapsulation by davorg (Chancellor) on Jul 13, 2000 at 19:43 UTC
That's not to say that you can't make changes to @INC which will affect 'use' statements. Two ways that spring to mind are: Put the code that changes @INC in a BEGIN block. Use `use lib;` -- <http://www.dave.org.uk> European Perl Conference - Sept 22/24 2000, ICA, London <http://www.yapc.org/Europe/>	[reply]
RE: RE: RE: Re: function encapsulation by maverick (Curate) on Jul 13, 2000 at 19:54 UTC
True. You can also put the 'require's inside a BEGIN block and get their syntax checked by perl -c. I'm sure there's more examples we can think of... /\/\averick	[reply]
RE: RE: Re: function encapsulation by Buckaroo Buddha (Scribe) on Jul 20, 2000 at 17:41 UTC
then this raises an interesting question (for me at least) i should probably test this myself (and probably will but love discussion ... and have a deadline breathing down my neck ;) if i make a function, and encapsulate it in a file, then make calls to that function from a script which had been compiled using perl2exe... would the whole program still work? could i change the required and encapsulated function as needed? is this the basic concept behind a DLL file in windows? or are there more to them? i've not got a lot comp-sci so i'm trying to pick up advanced topics in programming on the fly, while simultaniously learning the basics i'd love some help me in gaining a deeper understanding of the whole system we're working in	[reply]