use Tk; use Tk::Xrm;
Result is that "matching" of name/Class with the options database follows the same rules as other X toolkits. This makes it more predictable, and makes it easier to have a single ~/.Xdefaults file which gives sensible results for both Tk and (say) Motif applications.
optionAdd('key' =
'value' [, priority])> ignores optional
priority completely and just does XrmPutStringResource().
Perhaps it should be more subtle and do XrmMergeDatabases() or
XrmCombineDatabase().
This version is a little slower than Tk's re-invention but there is more optimization that can be done.