We pick up the ability to refer to URI, associating an input Stream with its representation as a network (or local system) bytes easily as the following one-liner:
CL-USER> (with-open-file (stream #p"http://google.com/index.html")
(format nil "~A" (read-line stream nil)))
Underneath we have implemented a new subtype of PATHNAME, namely the type >URL-PATHNAME. We name this URL as opposed to URI as the underlying Java object is a java.net.URL with associated java.net.URLConnection that we'll be relying on for input sources.
Looking through an APROPOS for URL-PATHNAME shows the following related symbols:
CL-USER> (apropos (type-of #p"http://google.com/index.html"))
; No value
which we see the defined functions to set the AUTHORITY, SCHEME, FRAGMENT, and QUERY portions of a URL-PATHNAME.
After these modifications, the ABCL PATHNAME class now has two "beyond ANSI" subtypes, namely URL-PATHNAME and JAR-PATHNAME. A short document outlining the design of URL-PATHNAME can be found in our documentation directory.
In implementing URL-PATHNAME, we actually had the ability to analyze what another CL did for their implementation. We analyzed the CLForJava technical paper, but decided not to use their abstractions as detailed on a lengthy armedbear-devel post.