Re: demos

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

On Thursday 03 August 2006 12:10 pm, Daniel J Sebald  wrote:
>
> > Better yet would be to figure out a way to make all.dem itself
> > recognize and skip unsupported demos, but to my recollection past
> > discussions never came up with a reasonable way to do that.
>
> I think a function that allows executing a command without falling
> back to the command line would be nice.  Say "attempt"

Maybe, but it wouldn't actually help in the case of all.dem.
Falling back to the command line would leave you in the middle of
a sequence of now-useless commands.  What we need for the demo
case is some way of skipping the demo altogether.

Hmm.  I've got an idea that wouldn't have been possible before.

Now that we have all these GPVAL_***  variables, maybe
we should load one with the conditional compilation flags as
reported by "show version long".

gnuplot> print GPVAL_COMPILE_OPTIONS
-READLINE  +LIBREADLINE  +HISTORY  +BACKWARDS_COMPATIBILITY  
+BINARY_DATA  +GD_PNG  +GD_JPEG  +GD_TTF  +GD_GIF  +ANIMATION -NOCWDRC  
+X11  +X11_POLYGON  +MULTIBYTE  +USE_MOUSE  +HIDDEN3D_QUADTREE 
+DATASTRINGS  +HISTOGRAMS  +OBJECTS  +STRINGVARS  +MACROS  +IMAGE


Then we could do

  if (strstrt(GPVAL_COMPILE_OPTIONS,"+IMAGE")) load "image.dem"

Anyone see anything wrong with this approach?



-- 
Ethan A Merritt
Biomolecular Structure Center
University of Washington, Seattle WA