On Nov 16, 7:19 pm, Greg Weeks <greg.we... / arm.com> wrote:
> I have a bone to pick with the generally-wonderful Pickaxe regarding
> "Top-Level Execution Environment", which states:
>
>   At the top-level, we're executing in the context of some predefined
>   object [of class Object].  When we define methods, we're actually
>   creating (private) instance methods for class Object.
>
> The second sentence is true and helpful.  But the first sentence is only
> sort of true, and only because of some unexplained magic.  Here's what I
> mean.
>
> I'm not aware that "in the context of some ... object" has an
> established meaning other than what "instance_eval" does; and
> "instance_eval" does not provide a context for constant definitions.
> Also, "instance_eval" interprets "def"s in the context of the
> singleton-class of the object (I think), which is inconsistent with the
> second (correct) sentence.
>
> The second sentence remedies both of these deficiencies.  But the
> consistency of the two sentences requires some magic: Most code of
> interest is evaluated in the context of "class Object ... end", AND self
> is not Object.
>
> Mightn't it be better to have self == Object at the top-level?  Then no
> magic would be required.

A fair suggestion, but I bet three was a reason. Personally think they
should be separate things altogether. You can always add to Object,
but this "magic" prevents us from creating top-level methods without
infecting all other objects. I 'd rather see an implied:

  module Main
    extend self

    ...code...

  end

T.