http://www.perlmonks.org?node_id=1215748


in reply to Re^3: Tkx after coderef problem
in thread Tkx after coderef problem

The word is operator. If it's not an operator what is it a puppy?

It is not a puppy, it is a "dereferencing symbol"

https://perldoc.perl.org/perlref.html
"Because of being able to omit the curlies for the simple case of $$x , people often make the mistake of viewing the dereferencing symbols as proper operators"

"which sub is rAising invalid command?" It is the Tkx::after command that is raising invalid command when its time has arrived to actually call its argument.

"What command where?"The command is the one created by $tkxfsr->{after}{$afterid}{sub}=sub{ ...}; since the code address match.

"What is undefinex at time of sub call? " Nothing is actually undefined at the time of the call, but for some reason the execution part of Tkx:after thinks it is.