RDF API for PHP

BNF for RAP’s RDQL engine

NON-Terminals

CompilationUnit	::=	Query
CommaOpt	::=	(“,”)?
Query	::=	SelectClause (SourceClause)? TriplePatternClause (ConstraintClause)? (PrefixesClause)?
SelectClause	::=	(“SELECT” Var (CommaOpt Var)* \| “SELECT *")
SourceClause	::=	(“FROM” \| “SOURCE”) QuotedURI
TriplePatternClause	::=	“WHERE” TriplePattern (CommaOpt TriplePattern)*
TriplePattern	::=	“(“ VarOrURI CommaOpt VarOrURI CommaOpt VarOrUriOrLiteral “)”
ConstraintClause	::=	“AND” Expression (“,” Expression)*
PrefixesClause	::=	“USING” PrefixDecl (CommaOpt PrefixDecl)*
PrefixDecl	::=	Identifier “FOR” QuotedURI
Expression	::=	ConditionalOrExpression
ConditionalOrExpression	::=	ConditionalXorExpression (“\|\|” ConditionalXorExpression)*
ConditionalXorExpression	::=	ConditionalAndExpression
ConditionalAndExpression	::=	ValueLogical (“&&” ValueLogical)*
ValueLogical	::=	StringEqualityExpression
StringEqualityExpression	::=	EqualityExpression ((StrEqOp EqualityExpression) \| (RegexMatchOp RegexPattern))
StrEqOp	::=	“EQ” \| “NE”
RegexMatchOp	::=	“~~” \| “=~” \| “!~”
RegexPattern	::=	<REGULAR_EXPRESSION>
EqualityExpression	::=	RelationalExpression (EqOp RelationalExpression)?
EqOp	::=	“==” \| “ !=”
RelationalExpression	::=	AdditiveExpression (RelOp AdditiveExpression) ?
RelOp	::=	“<” \| “<=” \| “>” \| “>=”
AdditiveExpression	::=	MultiplicativeExpression (AddOp MultiplicativeExpression)*
AddOp	::=	“+” \| “-”
MultiplicativeExpression	::=	UnaryExpression (MulOp UnaryExpression)*
MulOp	::=	“*” \| “/” \| “%”
UnaryExpression	::=	PrimaryExpression \| “+” UnaryExpression \| “-” UnaryExpression \| “!” UnaryExpression
PrimaryExpression	::=	Var \| Literal \| “(“ Expression “)”
VarOrURI	::=	Var \| QuotedURI
VarOrUriOrLiteral	::=	Var \| QuotedURI \| Literal
Var	::=	“?” Identifier
Identifier	::=	<IDENTIFIER>
URI	::=	<URI>
QuotedURI	::=	“<” <URI> “>”
Literal	::=	URI \| NumericLiteral \| TextLiteral \| BooleanLiteral \| NullLiteral
NumericLiteral	::=	<INTEGER_LITERAL> \| <FLOATING_POINT_LITERAL>
TextLiteral	::=	<STRING_LITERAL> (“@” Identifier)? (“^^” URI)?
BooleanLiteral	::=	<BOOLEAN_LITERAL>
NullLiteral	::=	<NULL_LITERAL>