DOCUMENT START
NON-TERMINALS
	CompilationUnit	:=	Query <EOF>
// **** Debug point
	Query	:=	Prolog ( SelectClause | ConstructClause | DescribeClause | AskClause ) ( GraphClause )* ( NamedGraphClause )* ( WhereClause )? ( LimitClause )?
	Prolog	:=	( BaseDecl )? ( PrefixDecl )*
	SelectClause	:=	( <SELECT> ( <DISTINCT> )? ( Var )+ | <SELECT> ( <DISTINCT> )? <STAR> )
	DescribeClause	:=	( <DESCRIBE> ( VarOrURI )+ | <DESCRIBE> <STAR> )
	ConstructClause	:=	( <CONSTRUCT> ConstructTemplate | <CONSTRUCT> <STAR> )
	AskClause	:=	<ASK>
	GraphClause	:=	<WITH> ( SourceSelector )+
	NamedGraphClause	:=	<FROM> ( SourceSelector )+
	SourceSelector	:=	URIref
	WhereClause	:=	<WHERE> GraphPattern
	LimitClause	:=	<LIMIT> <INTEGER_10>
// ---- General Graph Pattern 
// Top of graph patterns
	GraphPattern	:=	PatternGroup
// A group made up of a list of triple patterns and other things.
// No outer brackets here.
	PatternGroup	:=	GraphOrPattern
	GraphOrPattern	:=	GraphAndPattern ( <UNION> GraphAndPattern )*
// TIDY: Check all ()* productions and convert to ()+ 
	GraphAndPattern	:=	( PatternElement )+
// A single thing -- one of
// + a single triple pattern
// + A group { ... }
// + OPTIONAL
// + GRAPH
// + UNSAID - removed
// + Constraint
	PatternElement	:=	( TriplePattern | GroupGraphPattern | NamedGraphPattern | OptionalGraphPattern | <AND> ConstraintPattern )
	PatternElementAsGroup	:=	( TriplePattern | GroupGraphPattern )
// ---- The various components of a graph pattern.
	GroupGraphPattern	:=	<LBRACE> PatternGroup <RBRACE>
	NamedGraphPattern	:=	( <GRAPH> <STAR> PatternElementAsGroup | <GRAPH> VarOrURI PatternElementAsGroup )
// Element UnsaidGraphPattern() : { Element el ; }
// {
//   <UNSAID> el = PatternElementAsGroup()
//     { el = new ElementUnsaid(el) ;
//       return el ;
//     }
// }
	OptionalGraphPattern	:=	<OPTIONAL> PatternElementAsGroup
	ConstraintPattern	:=	Expression
// ---- Triple Patterns

// Merge with next as rename as TriplePattern
	TriplePattern	:=	<LPAREN> VarOrURI VarOrURI VarOrLiteral <RPAREN>
// -------- -- Construct patterns
	ConstructTemplate	:=	( TripleTemplate )+
// Template ConstructGroup() : { Element el ; }
// {
//     { TemplateGroup g = new TemplateGroup() ; }
//   <LBRACE> ( t = ConstructElement() { g.add(t) ;} )+  <RBRACE>
//     { return elg ; }
// }
// 
// Template ConstructElement() : { Template t ; }
// {
//     t = TripleTemplate()
//     { return t ; }
// }

// Like a triple pattern but with possible bNodes.
	TripleTemplate	:=	<LPAREN> ( VarOrURI | BNode ) VarOrURI ( VarOrLiteral | BNode ) <RPAREN>
// ----
	VarOrURI	:=	( Var | URIref )
	VarOrLiteral	:=	Var
		|	Literal
	Var	:=	<VAR>
	BaseDecl	:=	<BASE> QuotedURIref
	PrefixDecl	:=	( <PREFIX> <QNAME_NS> QuotedURIref | <PREFIX> <COLON> QuotedURIref )
// -------------------------------------------------
// Constraint syntax follows.

// **** Debug point
	Expression	:=	ConditionalOrExpression
	ConditionalOrExpression	:=	ConditionalXorExpression ( <SC_OR> ConditionalXorExpression )*
	ConditionalXorExpression	:=	ConditionalAndExpression
	ConditionalAndExpression	:=	ValueLogical ( <SC_AND> ValueLogical )*
// End of boolean expressions
// (except unary NOT which is very tightly binding)

// PatternElements that are not operations on boolean terms.
	ValueLogical	:=	StringEqualityExpression
	StringEqualityExpression	:=	EqualityExpression ( <STR_MATCH> PatternLiteral | <STR_NMATCH> PatternLiteral )*
	EqualityExpression	:=	RelationalExpression ( <EQ> RelationalExpression | <NE> RelationalExpression )?
	RelationalExpression	:=	NumericExpression ( <LT> NumericExpression | <GT> NumericExpression | <LE> NumericExpression | <GE> NumericExpression )?
// **** Debug point
	NumericExpression	:=	AdditiveExpression
	AdditiveExpression	:=	MultiplicativeExpression ( <PLUS> MultiplicativeExpression | <MINUS> MultiplicativeExpression )*
	MultiplicativeExpression	:=	UnaryExpression ( <STAR> UnaryExpression | <SLASH> UnaryExpression | <REM> UnaryExpression )*
	UnaryExpression	:=	( <TILDE> | <BANG> ) BuiltinExpression
		|	<PLUS> BuiltinExpression
		|	<MINUS> BuiltinExpression
		|	BuiltinExpression
	BuiltinExpression	:=	<STR> <LPAREN> Expression <RPAREN>
		|	<LANG> <LPAREN> VarOrLiteral <RPAREN>
		|	<DTYPE> <LPAREN> Expression <RPAREN>
		|	<BOUND> <LPAREN> Var <RPAREN>
		|	<IS_URI> <LPAREN> Var <RPAREN>
		|	<IS_BNODE> <LPAREN> Var <RPAREN>
		|	<IS_LITERAL> <LPAREN> Var <RPAREN>
		|	URIref <LPAREN> Expression <RPAREN>
		|	PrimaryExpression
	PrimaryExpression	:=	( Var | Literal | FunctionCall | <LPAREN> Expression <RPAREN> )
	FunctionCall	:=	<AMP> URIref <LPAREN> ArgList <RPAREN>
	ArgList	:=	( VarOrLiteral ( <COMMA> VarOrLiteral )* )?
// ----------------------------------
// Literal terms (as in query literals - any value in the query)
	Literal	:=	URIref
		|	NumericLiteral
		|	TextLiteral
	NumericLiteral	:=	Integer
		|	FloatingPoint
	TextLiteral	:=	( <STRING_LITERAL1> | <STRING_LITERAL2> ) ( <LANGTAG> )? ( <DATATYPE> URIref )?
	PatternLiteral	:=	
// Node URL() : { Node n ; }
// {
//   //QuotedURI()
//   n = URI() { return n ; }
// }
	URIref	:=	QuotedURIref
		|	QName
	QName	:=	( <QNAME> | <QNAME_NS> )
	BNode	:=	<BNODE>
	QuotedURIref	:=	<Q_URIref>
	Integer	:=	<INTEGER_10>
	FloatingPoint	:=	<FLOATING_POINT>

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