Regexp::Assemble takes an arbitrary number of regular expressions and assembles them into a single regular expression (or RE) that matches all that the individual REs match.
As a result, instead of having a large list of expressions to loop over, a target string only needs to be tested against one expression. This is interesting when you have several thousand patterns to deal with. Serious effort is made to produce the smallest pattern possible.
It is also possible to track the original patterns, so that you can determine which, among the source patterns that form the assembled pattern, was the one that caused the match to occur.