strings strangle sac

Bugzilla Link	210
Created on	Mar 07, 2006 20:54
Resolution	FIXED
Resolved on	May 11, 2006 16:10
Version	1.00beta
OS	Linux
Architecture	PC
Attachments	xUTQuadFI.sac, UTQuadFI.sac

Extended Description

1. The attached kills sac2c w/-O3 and -noOPT. 
2..The QUADfi function shows what I think is a good example of
why the semantics of strtod are wrong:
 
I start out with a character vector that I want to convert to
a numeric vector. This requires repeated calls to strtod until
the string is exhausted. Meanwhile...
- I either have to do repeated catenations into the result, 
  as each result element is built, or
- Count the number of transitions from white space to non-white-space
to compute final result size.
- The fact that strtod returns a string means that the termination
test is  0 != strlen(string). If this is like C, it means that the
dumb thing has to iterate over the string looking for the NULL.
This is really really expensive, when you do it N times.
This whole class of functions should really work this way:
- define their behavior so that they're based on character vectors
(or matrices where that's appropriate - not sure I can think of one offhand),
rather tha strings
- Instead of returning a shorter string (as in strtod), return an offset
into the argument where scanning stopped. Thus, the termination condition
becomes: strtodres == shape(strtodarg)[0].