Re: Perl syntax checking without `perl -c`

Hi Ken,

> like 'perl -c ...', that will just check the syntax without executing any part of the code?

the problem is that imported functions can change the syntax.

Just think of something like sub foo (&) {} , which will only compile if it finds foo {...} later. That's the main reason why Perl is so hard to parse statically.

> The use statements will be my biggest problem; although, others may crop up here and there.

> "Can't locate SomeMod.pm in @INC ..."

OK let's suppose the exported functions don't change the syntax.

What you could do is pretending that "SomeMod.pm" was already loaded, by setting %INC in a BEGIN block.* No need to find a module which was already "loaded".

But these are kind of hairy workarounds, do you really think it's worth going down that road?

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery}

*) I seem to remember that perlrun allows you to inject a BEGIN without changing the actual code, just the way you start it.

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Re^2: Perl syntax checking without `perl -c` by kcott (Archbishop) on Dec 03, 2020 at 02:37 UTC
G'day Rolf, "the problem is that imported functions can change the syntax" You make a very good point; I hadn't considered that. I've only downloaded individual files (e.g. `Whatever.pm`) and these are all integrated into a much bigger framework; there will, in a number of places, be modules that change syntax. I really just wanted to get on with some work while the SysAdmin folks dealt with the disaster recovery. Setting up the environment — which not only involves code but also databases, web servers, etc. — would likely take substantially longer than the recovery (and, as I indicated above, depending on services affected, may not even be possible at this time). "But these are kind of hairy workarounds, do you really think it's worth going down that road?" No, I don't think so. :-) For now, I'll just rely on my editor's syntax highlighting and my own experience. In a day or two, I can upload all my changes and test in the full environment. Thanks for your feedback. — Ken	[reply] [d/l]
Re^3: Perl syntax checking without `perl -c` by LanX (Saint) on Dec 03, 2020 at 10:34 UTC
Hi Ken, > No, I don't think so. :-) OK. But just in case, here a tread where we discussed manipulating %INC . :) Re: Multiple Packages in a Module? (manipulate %INC) Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply]
Re^2: Perl syntax checking without `perl -c` by choroba (Cardinal) on Dec 03, 2020 at 10:43 UTC
Another workaround I sometimes use at work is to create a `fakelib/` directory with contents created like `echo 1 > SomeMod.pm` [download] Then include fakelib into your PERL5LIB (or run `perl -I /path/to/fakelib`). `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l] [select]
Re^3: Perl syntax checking without `perl -c` by Fletch (Bishop) on Dec 03, 2020 at 14:58 UTC
Seconded; I've used basically the same thing letting flycheck run on my desktop working copy at `$work` so that it's `perl -c` check behaves even though I don't have the same perl environment available as the production machines where the code actually runs. The cake is a lie. The cake is a lie. The cake is a lie.	[reply] [d/l] [select]
Re^4: Perl syntax checking without `perl -c` by LanX (Saint) on Dec 03, 2020 at 15:15 UTC
The problem I see with this filesystem approach is maintenance. What if a missing module was installed in the meantime? A module "FakeInc" called via something like `perl -MFakeInc -c` could check if the module is available before installing a facade. ~~~ Thinking about it, having a code hook at the last position of `@INC` could also handle all missing modules... from `require` : You can also insert hooks into the import facility by putting Perl code directly into the @INC array. There are three forms of hooks: subroutine references, array references, and blessed objects. update oops ... I didn't realized there was already a demo: Re: Perl syntax checking without `perl -c` Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l]
Re^5: Perl syntax checking without `perl -c` by stevieb (Canon) on Dec 05, 2020 at 17:00 UTC
Re^6: Perl syntax checking without `perl -c` by LanX (Saint) on Dec 05, 2020 at 17:44 UTC
Re^3: Perl syntax checking without `perl -c` by LanX (Saint) on Dec 03, 2020 at 14:49 UTC
Yeah, that's another good approach. I think it depends how many modules one needs to fake and often one needs them. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply]

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