[6.x] Add an eager() method to the lazy collection class

[JosephSilber]

The eager() method enumerates all of the lazy collection's values, and constructs a new LazyCollection instance, which will now be backed by an array:

$users = User::cursor();

$users = $users->eager();

$count = $users->count();

$users->each(function ($user) {
    //
});

The above will only fetch the users once. Without calling eager in between, the query would execute (and fetch all results) twice.

This is a pretty useless example, but is a clear illustration of what the eager method does.

[taylorotwell]

The naming of this and when to even use it are still very murky to me. 😄

[GrahamCampbell]

What about strict() as a method name?

[JosephSilber]

when to even use it are still very murky to me

Do you understand when a user would want to call lazy() on a regular collection? You may want to run lazy operations even on a list that is already all in memory.

eager is functionally equivalent to $lazyCollection()->collect()->lazy().

// These two end up doing the same thing:
$lazyCollection = $lazyCollection()->collect()->lazy();
$lazyCollection = $lazyCollection()->eager();

[BrandonSurowiec]

Would snapshot() be a clearer name?

[thecrypticace]

Yeah, I'm not a fan of the name cache. It feels too tied to actual persistent caching mechanisms. Tbh, snapshot() isn't a bad name. It seems pretty descriptive to me. In my lazy collection implementation I called this method eager() (as you eagerly collect the values into the collection — you are making it less lazy) which is another option.

[taylorotwell]

Definitely prefer eager.

[JosephSilber]

Updated.