From: "David A. Black" <dblack@...>
Date: 2007-09-26T01:16:28+09:00
Subject: Re: Why dynamic languages for ActiveRecord..?

Hi --

On Wed, 26 Sep 2007, Phlip wrote:

> ypomonh wrote:
>
>> I'm having problems understanding why people prefer to implement the
>> ActiveRecord pattern in dynamic languages. Of course it is very
>> convenient if you don't have to worry about what type is your column,
>> but dynamic languages are more than that.
>
> You are describing a "soft" language, such as Perl, JavaScript, or
> some aspects of BASIC. A variable can change its type based on its
> environment.
>
> Ruby is a strongly, dynamically typed language. Strong because nothing
> ever changes its type, and dynamic because you can add features to

I think there's part of a sentence missing there. I wanted to comment
on the first part anyway :-)

I'd say that the type of a Ruby object can change, but its class
cannot. That's based on an understanding of the object's type as a
kind of runtime snapshot of what the object can do and what messages
it understands.

This framing of it is, I believe, behind the deprecation of
Kernel#type (which I think only existed in the first place because
"class" was impossible to parse as a method name in some early Ruby
versions).

I find it a useful distinction, in part because otherwise one has to
come up with yet another term to refer to the thing that can change.


David

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