On 2011-09-03 22:47, Jonathan Wilkes wrote:
----- Original Message -----
From: Mathieu Bouchardmatju@artengine.ca To: Jonathan Wilkesjancsika@yahoo.com Cc: Chris McCormickchris@mccormick.cx; Miller Puckettemsp@ucsd.edu; "pd-list@iem.at"pd-list@iem.at Sent: Saturday, September 3, 2011 1:20 PM Subject: Re: [PD] (breaking symbols) was Re: find a list of numbers in a text file
On Wed, 31 Aug 2011, Jonathan Wilkes wrote:
Keep in mind that [list implode] must be smart enough to output the float atom "12" given the input "49 50". If it gives you
"symbol 12" then your
back to the [makefilename] madness from my original vanilla solution.
It's not that simple.
It needs to be that simple for the general case because Pd Vanilla has no (sensible) mechanism to convert a symbol atom into a float.
If symbol atoms which look like numbers to the naked eye are going to start flying around more freely in Pd then the docs need to explain how atoms are a kind of weird file cabinet where the label on the cabinet tells you which file-folder inside actually holds the data. So if you send the symbol-atom "15" to [max], the file clerk will complain because it's looking for a number but the label on the cabinet says "A_SYMBOL". (Additionally, if you tell the clerk to ignore the label and just pull out a number, the clerk will look in "A_FLOAT" and give you a "0", because the "15" is in the "A_SYMBOL" file-folder.)
Hm... is there a way you can tell the clerk to be a real go-getter when looking for a float atom inside a cabined labeled "A_SYMBOL" by just going ahead and seeing if the data in the "A_SYMBOL" file-folder looks like a number, and if so convert it to a float and send it on its way?
Any external can do that easily enough if it wants to by using sscanf with a format string:
int symbol_to_float (t_atom *atom, t_float *afloat) { int n; n = sscanf(atom->a_w.w_symbol->s_name, "%f", afloat); return n; /* afloat is valid if n is 1 */ }
But there are more ways of writing numbers than a single sscanf call can handle, so a real version would have to check all the expected input styles.
The function pd_defaultsymbol in m_class.c is the default symbol handler for objects that have no explicit symbol method. It could check to see if a non-default float method exists and if so try to convert the symbol to a float for the float method to eat.
Martin