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perlpackagemetaprogrammingpragma

Is there anyway to tell what features a package has enabled?

Let's say that I want to make sure someone implementing an interface has a specific experimental feature,

package Foo {
  use experimental "signatures";

}

Is there an way to determine what features, or more specifically "experimental features" that Foo has enabled?

Solution

  • No, because Foo does not have features enabled; features are tied to the lexical scope, not the package.

    Code within that lexical scope or called from that lexical scope can theoretically test enabled features with the hinthash return value from caller, but this value is essentially undocumented internals. Code from outside that scope would have to use something like PadWalker.

    A better approach if you just want to check for the presence or absence of particular features in certain files would be to write perlcritic rules.