From: "enduro (Sven Suska)" <sven715rt@...>
Date: 2007-05-15T19:31:02+09:00
Subject: Re: Why was the "Symbol is a String"-idea dropped?

Robert Klemme schrieb:

> On 15.05.2007 03:07, enduro wrote:

>> Or, in other words: if the decision to unify Symbol and String would
>> have been taken at early stages of Ruby development, then the
>> general usage would have adapted to this, and ...
>> we might be happier with the result today.
>
> I am in no way unhappy with the way it is today. 
> Strings and symbols serve different purposes although there is some 
> overlap. 
> I rarely feel the need to convert between the two.

I see.
And I am quite surprised. Because judging from your online activity
you seem to have some experience.
Perhaps it is also my programming style: I may use symbols where one
normally would use strings.


> I am not aware of a situation where you would need to mix them as hash 
> keys. 
> And to make the distinction is pretty easy most of the time IMHO.

Not aware? I mean Rails mixes them, right?


> 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?
The only thing that comes to my mind just now, is
that a separated Symbol class easily provides
distinct special values for a parameter that would normally carry a String.

> Note though, that all these issues have nothing to do with the question
> whether String and Symbol should be connected inheritance wise. 
> IMHO that's mostly an implementation decision in Ruby.

Yes, I agree.
I am actually interested in the implications for the programmer.
My original question just arised out of the notion
that this implementation decision could have been a move
in a (to my mind) favourable direction.


>> Yes, I sometimes think of that separation of Symbol from String
>> as a tiny impurity in the Ruby crystal.
>
>
> Personally I believe it creates more expressiveness. 
> If you view this as impurity, there are a lot of them in Ruby because 
> Ruby's focus
> has always been on pragmatism and not purity

1.  The  core structure must of course be large enough,  and a  large 
structure may  look impure.
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.)

>> So, I'll just have to come to terms with it. :-)
>> (And I will, of course -- there are enough other fascinating 
>> issues... :-) )
>
> The capability to adjust to reality is a useful one IMHO. :-)

Well, yes, sometimes I'm glad someone tells me that. :-)


>> create a class hierarchy similar to the Float/Integer hierarchy?
>> String < Stringlike
>> Symbol < Stringlike
>
> Why not?  StringLike could even be a module that relies solely on [] 
> and length to do all the non mutating stuff.

Ah, interesting. Can't follow the implications right now.


> Given the fact that I don't mix symbols and strings as Hash keys I 
> wouldn't benefit -
> but it would not hurt me either. :-)  YMMV

Yes that was the idea behind it: to benefit some and not to hurt the others.


> Credits also go to the community that is still among the most 
> civilized online communities I know so far!

Indeed, I'm experiencing it right now!
Thanks a lot!

Sven