#
# Context-free grammar (CFG) vocabulary
#

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
@prefix cfg: <http://www.w3.org/2000/10/swap/grammar/bnf#>.
@prefix : <http://www.w3.org/2000/10/swap/grammar/n3#>.
@prefix n3: <http://www.w3.org/2000/10/swap/grammar/n3#>.
@prefix list: <http://www.w3.org/2000/10/swap/list#>.
@prefix doc: <http://www.w3.org/2000/10/swap/pim/doc#>.
@prefix dc: <http://purl.org/dc/elements/1.1/>.

@keywords a, is, of.

<http://www.w3.org/2000/10/swap/grammar/bnf> doc:rules <bnf-rules>;
    dc:creator <http://www.w3.org/People/Berners-Lee/card#i>;
    rdfs:comment """
    This ontology contains terms for defining a context-free grammar.
    The basic property is mustBeOneSequence which is equivalent to
    the expression of a production in the original simple BNF.
    Rules can be used to convert into and out of shorthand forms such
    as optional, repeating and token-separated list forms.
    Terminals are described either as a string, which is represented by itself,
    or are defined by a regular expression using cfg:matches. 
    """.

#cfg:canBeSequence a rdf:Property;
#	rdfs:domain cfg:Term; rdfs:range cfg:SequenceOfProductions;
#	rdfs:comment
#"""If you use cfg:canBeSequence to define a BNF vocabulary, then the reader
#has to assume that all possible productions are in the BNF file (or, generally,
#in the N3 formula) you are dealing with.
#Other possible vocabularies would explicitly list the "canBeSequence as a set of
#cfg:mustBeOneSequence"
#""".
#
#cfg:canBe rdfs:domain cfg:Term; rdfs:range cfg:Production.

cfg:mustBeOneSequence a rdf:Property;
	rdfs:label "productions";
	rdfs:domain cfg:Production; rdfs:range cfg:ListOfSequencesOfProductions;
	rdfs:comment

"""This is the core property you need to define a BNF production.
It defines the list of the only sequences to which a given 
term may expand.  Each sequence is just a list of other productions in order.
""".

cfg:Token rdfs:subClassOf cfg:Production;
	rdfs:label "token";
	rdfs:comment """A terminal, aka atomic, production,
	defined as string or regexp""".

cfg:matches	 a rdf:Property;
		rdfs:label "matches";
		rdfs:domain cfg:Token;
		rdfs:range  cfg:RegularExpression;
		rdfs:comment """The given token is defined by the
		regular expression which a token must match""".

cfg:canStartWith  a rdf:Property;
		rdfs:domain cfg:Production;
		rdfs:label "can start with";
		rdfs:comment """The production can only start with the given
		representative character. In the case that a token starts
		with always the same character, that is the one given.
		In th eevent that it can start with alpha character, 'a'
		is given; if it can start with a numeric, '0' is given
		as the value for this predicate.  This predicate is used
		only when a predictive parser is possible and desired.""";
		rdfs:range cfg:String.

# Sugar

cfg:zeroOrMore 
	rdfs:label "zero or more";
	rdfs:domain cfg:Term; rdfs:range cfg:Production.


cfg:commaSeparatedPeriodTerminatedListOf
	rdfs:label "comma-separated period-terminated list of";
	rdfs:domain cfg:Production;
	rdfs:range cfg:Production.

cfg:mustBe    
	rdfs:domain cfg:Production;
	rdfs:range cfg:Production.
	
# Meta

cfg:syntaxFor a rdf:Property;
    rdfs:domain	cfg:Production;
    rdfs:label "language";
    rdfs:range	cfg:Language.
    
cfg:internetMediaType a rdf:Property;
    rdf:domain cfg:Language;
    rdfs:label "internet media type".

#ends