From: Ricky Ng <dummey@...>
Date: 2013-01-20T05:07:39+09:00
Subject: Re: Module including other module.

--bcaec55556b00f752304d3a9ac6b
Content-Type: text/plain; charset=ISO-8859-1

Ahh, that makes sense! Thanks Xavier!



On Sat, Jan 19, 2013 at 3:52 AM, Xavier Noria <fxn@hashref.com> wrote:

> I asked about this to Matz in the past and it works that way basically as
> a consequence of the implementation.
>>
>>
> As you probably know, MRI stores a linear flat chain of ancestors of
> a class or module. Each ancestor has a pointer to its own direct ancestor
> in the chain of that particular class or module conceptually (there are
> indirections but they are not important).
>
> Thing is, albeit new methods are found because method name resolution
> follows the pointers at the time of the call (conceptually), and albeit if
> you include another module in the very class the pointers are
> adjusted, when you include a 2nd order module the ancestor chains of the
> classes or modules the enclosing module was already mixed in are not
> updated and reflattened so to speak.
>
> Indeed, modules just do not keep that information, they do not know where
> they have been included. So that update is not even possible with the
> current implementation.
>
> Matz said he would be willing to make this work provided the
> implementation had no performance penalty.
>
> Sent from my iPhone
>



-- 
Incoherently,
Ricky Ng

--bcaec55556b00f752304d3a9ac6b
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">Ahh, that makes sense! Thanks Xavier!<div><br></div></div>=
<div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">On Sat, Jan 1=
9, 2013 at 3:52 AM, Xavier Noria <span dir=3D"ltr">&lt;<a href=3D"mailto:fx=
n@hashref.com" target=3D"_blank">fxn@hashref.com</a>&gt;</span> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">I asked about this to Matz in the past and i=
t works that way basically as a consequence of the implementation.<blockquo=
te class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc so=
lid;padding-left:1ex">

</blockquote><div><br></div><div>As you probably know, MRI stores=A0a linea=
r flat chain of ancestors of a=A0class or module. Each ancestor has a point=
er to its own direct ancestor in the chain of that particular class or modu=
le conceptually (there are indirections but they are not important).</div>

<div><br></div><div>Thing is, albeit new methods are found because method n=
ame resolution follows the pointers at the time of the call (conceptually),=
 and albeit if you include another module in the very class=A0the pointers =
are adjusted,=A0when you include a 2nd order module the ancestor chains of =
the classes or modules the enclosing module was already mixed in are not up=
dated and reflattened so to speak.</div>

<div><br></div><div>Indeed, modules just do not keep that information, they=
 do not know where they have been included. So that update is not even poss=
ible with the current implementation.</div><div><br></div><div>Matz said he=
 would be=A0willing to make this work provided the implementation had no pe=
rformance penalty.</div>

<div><br></div><div>Sent from my iPhone<span></span></div>
</blockquote></div><br><br clear=3D"all"><div><br></div>-- <br>Incoherently=
,<br>Ricky Ng
</div>

--bcaec55556b00f752304d3a9ac6b--