Wilbur: DAML

DAML Parser as an Extension of the RDF Parser
Constructing DAML Lists
URI Constants

1. DAML Parser as an Extension of the RDF Parser

daml-parser [Class]

This class implements a DAML parser (technically a DAML+OIL December 2000 parser), as an extension (i.e., a subclass) of the Wilbur RDF parser (class rdf-parser). The extension basically consists of a new state (:daml-collection) in the parser's state machine to handle the "daml:collection" parse type, and specializations of four methods: parse-using-parsetype (which forces the the parser's state machine into the :daml-collection state), attach-to-parent (which "grows" a DAML-list from the end when the parser is in the :daml-collection state), as well as nox:start-element and nox:end-element (which handle the transitions to and from the :daml-collection state; nox:end-element also terminates the DAML list by replacing the last, incomplete node with a reference to daml:nil).

The daml-parser class can be used in place of the rdf-parser class in all functions which accept this class (namely parse-db-from-file and parse-db-from-stream).

2. Constructing DAML Lists

DAML lists are essentially similar in structure to Common Lisp lists as they consist of dotted pairs (nodes with properties daml:first and daml:rest). Consequently we have defined two functions, daml-list and daml-cons, that are equivalent to the Common Lisp functions list and cons. Converting

daml-list (&rest items) [Function]

This function takes an arbitrary number of (Common Lisp) objects and constructs a DAML list. The head of this list (a node instance) is returned. Lists are terminated with a reference to -daml-nil-. If you want to turn an existing (Common Lisp) list into a DAML list, use

(apply #'daml-list list)

daml-cons (first rest &optional uri) [Function]

This function takes two Common Lisp objects, first and rest (in practice, rest should be a node instance) and constructs a DAML "dotted pair" (a node instance, which is returned).

3. URI Constants

The system defines a set of constants for useful DAML URIs (strings). In the following table, the prefix "daml" is assumed to denote the value of -daml+oil-uri-.

Constant	Value
`-daml+oil-uri-`	`"http://www.daml.org/2000/12/daml+oil#"`
`-daml-list-uri-`	`daml:List`
`-daml-first-uri-`	`daml:first`
`-daml-rest-uri-`	`daml:rest`
`-daml-nil-uri-`	`daml:nil`