Re: When is "use module" not the same as require+import?

Not exactly. The documentation says:

It is exactly equivalent to

    BEGIN { require Module; Module->import( LIST ); }
[download]

And the BEGIN{} block makes all the difference. The BEGIN means that the code is run immediately after Perl has reached the closing curly brace. Which is well before Perl runs the code that initializes your @fields array. Putting the assignment to @fields into a(nother) BEGIN block would alleviate that problem.

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Re^2: When is "use module" not the same as require+import? by AZed (Monk) on Sep 18, 2008 at 19:23 UTC
Whee, except that comes with the additional interesting quirk that you can't actually declare the array in the BEGIN, because of course it will go out of scope between that block and the fresh BEGIN block implicit in `use`. What a mess. Looks like require+import is actually cleaner-looking. Thanks, both to you and moritz below, since the versioning issue is also good to know.	[reply] [d/l]
Re^3: When is "use module" not the same as require+import? by JadeNB (Chaplain) on Sep 18, 2008 at 20:34 UTC
It seems that you can get around the scoping issue by not leaving the `BEGIN` block: `BEGIN { my @fields = qw/field1 field2/; use fields @fields; } my $self = fields::new; $self->{field1} = 'value1';` [download] works just fine for me. It may fairly be argued that this is not much different from putting a `require` and `import` inside the `BEGIN`, though. UPDATE: ikegami correctly points out that I must not have tested what I thought I tested, because this code doesn't work. Sorry. I think Bloodnok's solution (adapted to `use fields`) works, though.	[reply] [d/l] [select]
Re^4: When is "use module" not the same as require+import? by ikegami (Patriarch) on Sep 19, 2008 at 19:20 UTC
`BEGIN { my @fields = qw/field1 field2/; use fields @fields; }` [download] is equivalent to `BEGIN { my @fields = qw/field1 field2/; BEGIN { require fields; fields->import(@fields); } }` [download] which is compiled and executed as follows: `my @fields = qw/field1 field2/;` is compiled `require fields;` is compiled `fields->import(@fields);` is compiled `require fields;` is executed `fields->import(@fields);` is executed `my @fields = qw/field1 field2/;` is executed As you can see, an empty array is passed to the module. I believe you were mistaken when you claimed it worked.	[reply] [d/l] [select]
Re^3: When is "use module" not the same as require+import? by Bloodnok (Vicar) on Sep 19, 2008 at 16:51 UTC
An alternative to get round the scoping problem is... `use vars qw/%a_hash/; BEGIN { $a_hash{key} = qw/val/; } . .` [download] A user level that continues to overstate my experience :-))	[reply] [d/l]