Implementation notes

History

Ystok-URI is based on

• uri.lisp from portableaserve, Jochen Schmidt;
• uri.cl, Franz, Inc.
• puri, a well-known portable follower of the above two, which does not support percent-encoding/decoding.

Implementation details

1. URIs are represented by instances of a Common Lisp structure type.
2. Percent-encoding and decoding are supported for all components. The path and query parts are first split into elements then decoded.
3. By default, all component (except uri-string cache) are stored percent-decoded. Use cautiously if you overwrite this default behavior!
4. Decoded userinfo is stored in plist with indicators :user and :password.
5. The print-object never outputs the password.
6. On changing any "public" component slot via setf, the following internal cache slots are not cleared automatically: %parsed-path% - should be affected by (setf uri-path), string - should be affected by (setf uri-any_slot) except password. You must invoke clear-cache explicitly.
7. Query
   • when decoded, query is always stored parsed as an alist of the form:
     ((parameter . value) ...),
   • the *query-char-p* special and query-char-p key parameter allow more (national) characters to be accepted not percent-encoded inside a query part.
8. Fragment
   • the empty string is accepted as a fragment if # is present;
   • the *fragment-char-p* special and fragment-char-p key parameter allow more (national) characters to be accepted not percent-encoded inside a fragment part.

Compatibility notes

1. A completely empty URI is represented as "#". In contrast, Franz and PURI implementations replace an empty URI by "/".
2. As a URI object is represented as a structure (not a CLOS object), its slot accessors are ordinary (not generic!) functions.

Unsupported features

1. URN.
2. Interning URI.

See also

• Change log