From: Eric Mahurin <eric_mahurin@...>
Date: 2005-09-14T06:50:06+09:00
Subject: Re: yet another simple command-line option parser

--- Jim Freeze <jim@freeze.org> wrote:

> In one way what you are suggesting is just a serialization
> method, it just so happens that you are suggesting a string
> be used
> to store the serialized data.
> 
>   obj.to_s.from_s == obj #=> true

With my proposal you would write the above as:

obj.class.from_s(obj.to_s) == obj #=> true

But, the intent is not to do something like Marshal does.  I'm
only proposiing klass.from_s methods where it makes sense, not
for handling all classes like Marshal does.  Only if you would
want to parse an object of a certain type from a human
readable/writable string would you want to make a from_s class
method for that type.

On top of that, Marshal really doesn't help with type
conversion.  It only converts from a type to a machine readable
byte stream and back.  It's kind of like changing the storage
from memory to file like mmap does??  YAML seems similar too.

> Which is essentially a serialization of obj, and is OO. 
> Right now, Marshal is functional
> 
>    Marshal.load(Mashal.dump(obj)) == obj #=> true
> 
> One could argue that we have this, but with YAML.
>   YAML.load(obj.to_yaml) == obj #=> true
> 
> So, why don't we add a #from_yaml or #yaml_load to every
> object? I don't think I want this done automatically, but it
> would be nice to have it available so I can extend a class or
> object as needed.

I'm not sure what that would buy you.

> I think that every time we visit this subject, it goes back
> to
> similar arguments as to why every object doesn't have puts,
> such as  "fred".puts. Matz has made statements on this
> which I agree with. Personally I think that puts("fred") is
> more natural.

It probably ends up like that because in C++ objects can write
themselves out to a stream and read themselves in from a
stream.  I like what is there now too.  I haven't used C++ in a
while, so I can't say a whole lot about how it is managed
(where the methods live).

> But, I'm warming up to #from_s more and more, but still not
> sure yet.

Good.  I'd like to know what you finally decide on for your
command-line parser.

> On 9/13/05, Eric Mahurin <eric_mahurin@yahoo.com> wrote:
> 
> > From my perspective, the only reason for the distinction
> > between Fixnum and Bignum is the efficiency (runtime and
> > memory) of Fixnum - a very good benefit.  Otherwise, I
> think
> > you should consider them the same.  Many of the methods in
> 
> Agreed
> 
> -- 
> Jim Freeze
> 
> 


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