ObdalibComponentsDatalogParser

Table of Contents Introduction Datalog grammar Examples Input query using Datalog syntax Input query using SWIRL syntax Input query with caret symbol Supported terms Multiple rules Recursive object term No head No body SELECT ALL input Empty term in the head Without prefix definitions

Introduction

Datalog grammar

[1]	parse	::=	prog EOF
[2]	prog	::=	base? directive* rule+
[3]	directive	::=	'prefix' prefix '<'uriref'>'
[4]	base	::=	'base' '<'uriref'>'
[5]	rule	::=	datalog_syntax_rule / swirl_syntax_rule
[6]	prefix	::=	STRING_PREFIX/':'
[7]	uriref	::=	STRING_URI
[8]	datalog_syntax_rule	::=	head? ':-' body?
[9]	swirl_syntax_rule	::=	body? '->' head?
[10]	head	::=	atom
[11]	body	::=	atom ((','/'^') atom)*
[12]	atom	::=	predicate '(' terms ')'
[13]	predicate	::=	full_name
[14]	terms	::=	term (',' term)*
[15]	qualified_name	::=	prefix id
[16]	plain_name	::=	id
[17]	full_name	::=	uriref
[18]	term	::=	object_term uri_term
[19]	variable_term	::=	'*'
[20]	literal_term	::=	STRING_LITERAL / STRING_LITERAL2
[21]	object_term	::=	function '(' terms ')'
[22]	uri_term	::=	STRING_URI
[23]	id	::=	ID_PLAIN
[24]	function	::=	full_name
[25]	ID_PLAIN	::=	ID_START (ID_CORE)*
[26]	ID_START	::=	ALPHA / '_'
[27]	ID_CORE	::=	ID_START / DIGIT
[28]	SCHEMA	::=	ALPHA (ALPHA/DIGIT|'+'|'-'|'.')*
[29]	URI_PATH	::=	ALPHA/DIGIT|'_'|'-'|':'|'.'|'#'|'?'|'/'
[30]	ALPHA	::=	[a-z] / [A-Z]
[31]	DIGIT	::=	[0-9]
[32]	STRING_URI	::=	SCHEMA '://' (URI_PATH)*
[33]	STRING_LITERAL	::=	'"' .* '"'
[34]	STRING_LITERAL2	::=	''' .* '''
[35]	STRING_PREFIX	::=	ID':'

Examples

Input query using Datalog syntax

base        <http://base.org/stuff/1.0/>
prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
abc:p($x, $y) :- :q($x), r($y)

Input query using SWIRL syntax

base        <http://base.org/stuff/1.0/>
prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
:q($x), r($y) -> abc:p($x, $y)

Input query with caret symbol

base        <http://base.org/stuff/1.0/>
prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
abc:p($x, $y) :- :q($x) ^ r($y)

Supported terms

prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
abc:p($x, $y) :- :q($x, "Person"), :r(:obj($y, "Student"), http://example.org/stuff/1.1/FUB)

Multiple rules

prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
abc:p($x) :- :q($x, "Person")
abc:r($y) :- :s($y, http://example.org/stuff/1.1/FUB)
abc:t($z) :- :u($z, f(http://example.org/stuff/1.2/Occupation, "Student"))

Recursive object term

prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
abc:p($x) :- :q($x, :rec1(http://example.org/stuff/1.1/FUB, 
                    :rec2(http://example.org/stuff/1.2/Occupation, 
                    :rec3(http://example.org/stuff/1.3/Degree, "Master"))))

No head

prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
 :- :q($x)

No body

prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
abc:p($x) :-

SELECT ALL input

base        <http://base.org/stuff/1.0/>
prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
abc:p(*) :- :q($x), r($y)

Empty term in the head

base        <http://base.org/stuff/1.0/>
prefix abc: <http://www.abc.org/1999/02/22-abc-syntax-ns#>
prefix    : <http://example.org/stuff/1.0/>
abc:p() :- :q($x), r($y)

Without prefix definitions

http://www.abc.org/1999/02/22-abc-syntax-ns#p($x, $y) :- 
      http://example.org/stuff/1.0/q($x), 
      http://base.org/stuff/1.0/r(http://example.org/stuff/1.0/s($y, "Student"), http://example.org/stuff/1.1/FUB)