From: "enduro (Sven Suska)" <sven715rt@...>
Date: 2007-05-15T20:49:48+09:00
Subject: Re: Why was the "Symbol is a String"-idea dropped?

Hello again,

Robert Klemme schrieb:

> On 15.05.2007 12:31, enduro (Sven Suska) wrote:
>
>> Perhaps it is also my programming style: I may use symbols where one
>> normally would use strings.
>
> Yeah, maybe.  So where are you using symbols where one normally would 
> use strings?

Let me guess, because I don't know if I am really the only one:
1. Multipurpose-names:
  Like option-names, used as hash keys but also as names and labels for 
the corresponding graphics control etc.
2. Logging:
  Giving a brief hint in the form of a symbol (not the log level), well 
just because it is easier to type and looks nice

>> Not aware? I mean Rails mixes them, right?
>
> I don't use Rails. :-)))

Oops :-), offending agian, am I? :-)
:-)


>>> Frankly, I believe there is an inherent advantage that you can use 
>>> symbols vs. strings in code.
>>> And I mean not only performance wise but also readability wise.
>>
>> Readability-wise: precisely what advantage?
>
> If I see a symbol being used as a Hash key I immediately know (or 
> rather guess)
> that there is only a limited amount of them and they are known 
> beforehand,
> like with options.
>
> # silly example
> opts = {
>   :length => 12,
>   :width => 30,
> }
> # other code
> resize( opts[:length] )

Sorry, don't get me wrong:

I DID NOT MEAN TO REMOVE the Symbol class.
Nor Symbol literals.

Thus, your examples would be valid and semantically equivalent code
after a "unification" of the classes (regardless if Symbol < String or not).
Or I'd better not call it "unification", I don't have a good word,
perhaps "joining" would be better.

> Don't forget the optical distinction between using 'string', "string" 
> and :symbol.

Also, this won't be affected, see above.


>>> [...] on pragmatism and not purity
>>
>> 1.  The  core structure must of course be large enough,  and a  large 
>> structure may  look impure.
>
> This somehow reminds me of 
> http://en.wikipedia.org/wiki/G%C3%B6del%27s_incompleteness_theorem

... mystery will always remain ...


>> 2.  But regarding this particular question: My original notion was 
>> that keeping
>>     Symbol and String too separate is not pragmatic.
>>     (I may change my mind on that, if I read more posts like yours, 
>> though.)
>
> Just reread mine a few times - then you don't need the other postings 
> any more. 
> That's more efficient - you'll save bandwidth and reading is actually 
> faster if you know the text already.  :-))

Well,
as Ruby-users,
we don't sacrifice our fun to the god of efficiency, do we... :-)


Cheers,
Sven