On Tue, Dec 08, 2009 at 12:52:00PM -0300, Stephen Eilert wrote: > A few days ago I had a difficult bug to diagnose, which happened because I > was trying to use uri-generic with uri-dispatch, instead of uri-common. > > What is the purpose of uri-generic anyway?
It is an implementation of RFC 3986, which is much more broadly applicable than just in web URIs. For example, URNs like urn:ietf:rfc:3986 are also URIs, but not URI-commons. They have no authority (user/pass/hostname/port combination), and no query string either, only a path. Some other schemes *do* have query strings, but not x-www-form-urlencoded ones. The uri-generic egg is intended for handling the full generality of all these types of URIs, whereas uri-common is intended for the specific "common" subset of URIs which are usually used on the web, to indicate a host, port and path indicating a resource on that host, with optionally an x-www-form-urlencoded query to pass to that resource for further processing. uri-common adds a few extra conveniences like more complete path decoding (all percent-encoded bits are fully decoded) because it knows this is allowed since the path's components are separated by slashes but have no additional separators with special meaning inside. Other schemes can't be handled this way. For example, the URN scheme mentioned above has a colon (:) which has special meaning, so %3A could not be decoded into : until after the parts are separated; urn:foo%3Abar:qux would be decoded to "foo:bar:qux", and hence it would be indistinguishable from urn:foo:bar:qux. So, to summarize: you would never need or use uri-generic unless you're writing a more specific URI parser for other schemes than the common ones. Cheers, Peter -- http://sjamaan.ath.cx -- "The process of preparing programs for a digital computer is especially attractive, not only because it can be economically and scientifically rewarding, but also because it can be an aesthetic experience much like composing poetry or music." -- Donald Knuth _______________________________________________ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users