From: Gavin Sinclair <gsinclair@...>
Date: 2003-02-19T13:45:42+09:00
Subject: Re: String#+ operatorbroken?

On Wednesday, February 19, 2003, 3:25:49 PM, Jason wrote:

>> 
>> Remember, s += "whatever" is a syntax sugar for
>> 
>>   s = s + "whatever"
>> 
>> so that it allocates new string object every time, whereas
>> 
>>   s << "whatever"
>> 
>> appends "whatever" to existing string object.
>> 
>>                                                       matz.
>> 

> Hmm. Would it make sense to 'special-case' that? They accomplish the
> same thing logically (right?), and I would expect a language to
> evolve out these hidden 'performance-bombs'. In fact, anytime
> there's an operator= method, maybe it should never allocate a new
> object?

This was discussed fairly extensively on -talk not so long ago.  Check
the archives of the last few months.

Basically, programmers have to take some responsibility for the
methods they use.  It's something of a Ruby idiom to use << for
appending, and if you want to program in Ruby, you need to learn some
Ruby idioms.

Also consider the fact that the "+" method can be redefined.

Gavin