[PD] (breaking symbols) was Re: find a list of numbers in a text file

Mathieu Bouchard matju at artengine.ca
Sat Sep 10 21:01:17 CEST 2011


On Tue, 6 Sep 2011, martin.peach at sympatico.ca wrote:

> The disaster would be if Pd tried to guess what the user intends based 
> on some general idea of what Pd is 'for'. For instance I've been working 
> on an xbee external where I need to specify numbers like 0x0a060123 for 
> the remote address. I do that by interpreting the symbol as a 64-bit 
> integer internally but I would not expect any other external to do this 
> unless it needs to.

The xbee external uses a function that shows that it expects to read a 
symbol where you gave it the 0x0a060123 symbol. Therefore Pd would not do 
any implicit conversion, because it's being requested to give a symbol 
atom as a symbol.

However, if ever 0x0a060123 is to be parsed as a float (that's a different 
issue, actually), then xbee would be getting 168165667 rounded to 
168165664 and then it would be implicitly converted to 
gensym("168165664"). But that's a parser difference, and not a difference 
of implicit type conversions. The solution would be to backslash it or 
doublequote it.

Perhaps it is confusing because we are talking about several related 
propositions at once :

  * implicit conversion to replace type mismatch errors

  * getting atom_string to write backslashes to files and to messageboxes,
    to match what the parser can already do

  * modifying both the parser and atom_string, to change the meaning of
    doublequotes

and AFAIK, no-one talked about adding support for aztec numerals or 
parsing «half-dozen» as meaning {A_FLOAT,6}.

  _______________________________________________________________________
| Mathieu Bouchard ---- tél: +1.514.383.3801 ---- Villeray, Montréal, QC


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