Thank you for the feedback. Yes, the precedence is a question for me. Maybe I will change this.
If I shift it behind concatenation there could be another problem. E.g. with non-associative : should be illegal. And I am not sure how to treat this:
cat:dog:mouse
In the current version I inject the epsilon (empty string). It looks natural E.g. to remove every second letter I could run '..:' which is technically '.(.:eps)':
echo 'abcde' | ./trre '..:'
result: 'ace'
actually ':' association could have a meaning as a composition of regular relations; but I found it too complicated for now.
If I shift it behind concatenation there could be another problem. E.g. with non-associative : should be illegal. And I am not sure how to treat this:
cat:dog:mouse
In the current version I inject the epsilon (empty string). It looks natural E.g. to remove every second letter I could run '..:' which is technically '.(.:eps)':
echo 'abcde' | ./trre '..:'
result: 'ace'
actually ':' association could have a meaning as a composition of regular relations; but I found it too complicated for now.