A Sinatra-like DSL for Reel. Angelo also features before and after filter blocks, just like Sinatra. Filters are ordered as defined, and called in that order. When defined without a path, they run for all matched requests. With a path, the path is interpreted as a Mustermann pattern and params are merged. before filters can set instance variables which can be used in the route block and the after filter. For more info on the difference in how after blocks are handled, see the Errors section below for more info.