A topic closely related to pattern substitution is pattern removal. Let's face it, pattern removal is basically the same as replacing a pattern with nothing.
If pattern removal had exactly the same functionality as pattern substitution, we would not need it. However, pattern removal has a few cool tricks that would be difficult or even impossible to do with pattern substitution.
Pattern removal has two options: removing matched pattern prefixes or suffixes. In simpler words, it allows you to remove stuff either from the beginning or the end. It also has an option to stop after the first matched pattern, or to continue up until the last.
Without a good example, this might be a bit too abstract (it definitely was for us the ...
