RE: character substitution loop and eval

[Dill, John]

>Can you be a little more clear about this?
>
>How would you call my-subst and what do you want the resulting expansion
>to be?

For example, I would call

filtered_string=$(call my-subst,1 2 3 4 5,0123456789ABCDEFG)

would produce at the end 06789ABCDEFG.

It's a dummy example where I'm seeing if I can use eval to store state within a 
foreach construct.  I would like to implement toupper and tolower using just 
make and compare the performance (currently I use sed, but I'd like to avoid 
incursions into the shell as much as I can after seeing the performance 
comparison of subst with $(shell ...) calls from the O'Reilly book).  I also 
have some other character specific filtering to workaround some problem 
characters.  I'd like to build a foreach version of the multi-character subst 
using eval and temp variables instead of nested $(subst ...) calls if possible.

I use mingw32-make3.80, so I seem to be having problems using eval, or I don't 
know how to use it.

Thanks,
John D.