Re: user-defined function & string file name

[Ethan M. <merritt@u.washington.edu>]

On Thursday 30 June 2005 03:49 am, Juergen Wieferink wrote:
> This is possible without evaluating anything twice.  The major
> drawback is that this doesn't work well with GP_STRING_VARS being
> optional.  [Could STRINGs be allowed without GP_STRING_VARS for this
> special case?]

Yes, but that isn't sufficient.  The expression evaluation 
code would have to be modified so that const_express() will
do something reasonable if the next token on the command line
is a string literal.

By the time you do that, I don't see that you've saved much
over just enabling string variables. There's just not that much
code involved in handling string variables per se.  Any increase in
overall size comes from the addition of built-in string functions
like sprintf().

I don't see much down-side to permanently enabling string variables.
There have been no reports of string variables breaking existing
scripts or usage.  There are some desireable un-implemented
features, like the current discussion about using string-valued
functions as arguments "plot/splot/fit". But other than that the
feedback has been to point out places where the older test
isstring() should be replaced by the new, more general, code.
So far this has usually simplified the call site, rather than
complicating it. It's just kind of tedious inspecting and
revising the remaining 50+ instances of isstring() one by one.


-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195