From: Stu <stu@...>
Date: 2012-11-28T06:06:53+09:00
Subject: Re: Novice: Understanding instance 'variables' and methods

--485b390f7deaa794c104cf806d59
Content-Type: text/plain; charset=ISO-8859-1

attr methods actually do the creation, probably with convert to string
append the '@' sigil in front and run it through eval, of what symbol was
given to them.

If you need a quick conceptual open up irb and type:

 puts '@' + :verb.to_s

look into define_method, as well as other eval family methods.
Getter/Setters are simple syntax sugar as ruby allows the method name to
have '=' so we don't have to type get_verb or set_verb( val). attr is a
unique piece of automation for the common templating, boiler plate code,
you see in object oriented languages.

attr_accesor is a method which creates methods. It wouldn't be as obvious
if we where able to actually send the sigilled version of what's being
created instead of a symbol. attr_writer( @foo, @bar) would be a bit more
obvious. But that won't work as @foo is just a variable and one that is not
set. It would actually send the value nil and not the name which is why
using a symbol or string does.

--485b390f7deaa794c104cf806d59
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

attr methods actually do the creation, probably with convert to string appe=
nd the &#39;@&#39; sigil in front and run it through eval, of what symbol w=
as given to them.<br><br>If you need a quick conceptual open up irb and typ=
e:<br>
<br>=A0puts &#39;@&#39; + :verb.to_s<br><br>look into define_method, as wel=
l as other eval family methods. Getter/Setters are simple syntax sugar as r=
uby allows the method name to have &#39;=3D&#39; so we don&#39;t have to ty=
pe get_verb or set_verb( val). attr is a unique piece of automation for the=
 common templating, boiler plate code, you see in object oriented languages=
. <br>
<br>attr_accesor is a method which creates methods. It wouldn&#39;t be as o=
bvious if we where able to actually send the sigilled version of what&#39;s=
 being created instead of a symbol. attr_writer( @foo, @bar) would be a bit=
 more obvious. But that won&#39;t work as @foo is just a variable and one t=
hat is not set. It would actually send the value nil and not the name which=
 is why using a symbol or string does.<br>

--485b390f7deaa794c104cf806d59--