[PD] symbol anxiety

Mathieu Bouchard matju at artengine.ca
Tue Feb 24 07:21:34 CET 2009

On Mon, 23 Feb 2009, Phil Stone wrote:

> Oh!  Very good.  I didn't realize that an identical symbol would get 
> re-used.  For completeness' sake, I will make a new [ps-stopwatch] that 
> does not leak (and is plain vanilla, to boot).

Yes, it's re-used, which sort of goes with the fact that it doesn't 
get de-allocated, but that is also because it's less trouble (for pd 
itself) to have eternal symbols than mortal symbols.

But the re-use also goes with the fact that it's easier and faster to 
compare two symbol addresses (t_symbol *) than two string contents, and 
if pd _ensures_ re-use, then two identical addresses _mean_ two identical 

But all this pd symbol concept comes essentially as-is from 1961 LISP. It 
was then adopted by LOGO and Smalltalk in addition to all of the LISP 
variants, and then by Ruby, and then the Ruby guys figured out that in the 
end, a symbol type could be pretty useless if you had a good enough string 
type, so they almost merged them. Most other languages just have had a 
string type and improved on that instead of having symbol-vs-string or 
just symbols. All this to say I'm in favour of replacing symbols with 
strings (while still calling them "symbols" just because).

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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal, Québec

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