Provide a "severity" for each import usage

[Ocramius]

Currently, used symbols are all at the same level.

There are though some symbols that may be "soft" dependencies (rare cases) and may be flagged differently.

Therefore, this suggestion may eventually be discarded after some discussion/suggestions.

Some examples:

often used in polyfills, minor issue:

if (class_exists(Foo::class)) { ... }

often used to do duck typing against running systems with unknown dependencies: warning (because the API is not guaranteed to work/be stable)

if ($instance instanceof Foo) { ... }

bad one: we are not duck-typing here, so strictness is necessary:

function foo(Foo $foo) { ... }

Hope this helps :-)

[Ocramius]

Note: there are no no-issue cases. Even internal classes that are in default extensions should be marked as "notice" or such, because that stuff actually breaks on custom PHP installations (and it happens a lot!)