1. Builtin namespaces
N3 defines a core set of builtins: Builtins are grouped into distinct vocabularies depending on the N3 triple elements they operate on (e.g., string, list), or their particular topic (e.g., time, cryptography, log). Builtins are denoted by a controlled IRI defined in one of the core builtin namespaces:
- Crypto – http://www.w3.org/2000/10/swap/crypto#,
- List – http://www.w3.org/2000/10/swap/list#,
- Log – http://www.w3.org/2000/10/swap/log#,
- Math – http://www.w3.org/2000/10/swap/math#,
- String – http://www.w3.org/2000/10/swap/string#
- Time – http://www.w3.org/2000/10/swap/time#.
2. Builtin arguments
An N3 builtin operates on its arguments. An argument is a placeholder that refers to an N3 triple element from the builtin statement, i.e., the N3 statement where the builtin acts as a predicate.
In the simplest case, there are two arguments that respectively refer to the subject and object of the
builtin statement. For instance, statements such as 1 math:lessThan 2 have two arguments $s and $o, which is written as $s math:lessThan $o.
Arguments can be also represent a "deconstruction" of the subject or object in case of lists. For
instance, (1 2 3) math:sum 6 will have arguments $s.1 .. $s.n and $o, which is written as ($s.1 .. $s.n) math:sum $o.
2.1. Argument modes
For a given builtin, an argument will have a defined argument mode that stipulates whether it should be bound or not in the builtin statement. This binding requirement determines whether the argument can serve as builtin input, output, or both. Note that these modes are mostly based on Prolog argument modes.
++: input argument (bound, fully grounded)+: input argument (bound, possibly not fully grounded)-: output argument (bounded or not bounded)--: output argument (not bounded)?: either providing input or accepting output, or both.[*]: modifier indicating that an argument can have multiple solutions.
2.2. Argument domains
An N3 builtin often has an expected datatype for its arguments, called the domain datatype. If the datatype of an argument value, called the value datatype, does not match the domain datatype, it may be possible to cast the value’s datatype to, or substitute it for, the domain datatype.
The expected datatypes of arguments, i.e., domain datatypes, are defined per N3 builtin.
If the value datatype and domain datatype do not match, and no casting or substitution is possible, the builtin statement will be considered false. (We point out that this is in line with the concept of the builtin theory box: a BPG search using the builtin statement will not match any statement in the theory box when literal datatypes do not match.)
Below, we elaborate on the type casting, promotion or substitution that may be applied to align domain datatypes with value datatypes.
2.2.1. Numeric datatype promotion and substitution
If the numeric value datatype does not match the domain datatype, it may be possible to promote or substitute the numeric value datatype:
Numeric type promotion: A numeric value datatype that is derived from the domain datatype can
be promoted to the latter (e.g., xs:integer is derived from xs:decimal). This is done by casting
the original value to the required datatype.
Refer to XML Schema Part 2 for details on these datatypes.
If there is no direct derivation relation between the value and domain datatype, the following numeric type promotions can take place:
- A value of type
xs:float(or any type derived fromxs:float) can be promoted to typexs:double. The result is anxs:doublevalue that is the same as the original value. - A value of type
xs:decimal(or any type derived fromxs:decimal) can be promoted to either of the typesxs:floatorxs:double.
Numeric type substitution: if all values have the same numeric datatype, and this
datatype is derived from the domain
datatype (e.g., xs:integer is derived from xs:decimal), then the values can be used without any
casting. For example, if two xs:integer values are used for input where xs:decimal domains are
expected, then the values retain their datatype as xs:integer. The substituted numeric datatype
(in this case, xs:integer) will also apply to the builtin’s output, if any.
Builtins operating on any numeric type: some N3 builtins (e.g., math:sum) operate on values
of any numeric type (i.e., xs:numeric, the union of xs:double, xs:float, and xs:decimal).
I.e., their concrete input values may present any combination of numeric types. In that case, the
builtin can only be applied if all value datatypes can be promoted into a common numeric
datatype in the ordered list (xs:integer, xs:decimal, xs:float, xs:double). If so, at that
point, we rely on numeric type substitution. For instance:
- For a builtin with
xs:numericdomain datatypes, given two value datatypesxs:integerandxs:decimal, thexs:integervalue will be promoted toxs:decimalas the common numeric datatype. At that point, the twoxs:decimaldatatypes can be substituted forxs:numeric(numeric type substitution). If the builtin has an output, then the calculated value for this output will also have datatypexs:decimal. - For a builtin with
xs:numericdomain datatypes, given two values with datatypexs:integer, thexs:integerdatatype will simply be substituted forxs:numeric. If the builtin has an output, then the calculated value for the output will also have datatypexs:integer.
2.2.2. Other kinds of datatype casting
If the non-numeric value datatype does not match the domain datatype, it may be possible to cast the value datatype to the domain datatype:
String: A literal will be considered a "string" when it has an xs:string datatype, a rdf:langString datatype due to the presence of a language tag, or when it lacks a datatype.
- Casting from string: if an input value has an
xs:stringdatatype that does not match the domain, it may be possible to cast the string to the domain datatype, as defined in XPath. The resulting value representation must be a valid lexical form for the domain datatype. - Casting to string: if an input value is an IRI, or any kind of literal (incl. type
xs:anyUrior its derivations), and the domain isxs:string, then the value will be cast to a string as defined in XPath along with additional rules defined for SPARQL 1.1.
Other datatypes: other types of datatype casting may take place as defined in XPath.
Editors' Note:
There is a useful chart for casting primitive types to primitive types in XPath, a
subset of which is defined for SPARQL 1.1.
2.2.3. Scopes
Some N3 builtins have a scope as an argument (e.g., log:collectAllIn). A scope is either a concretely stated N3 graph, or the reasoning scope, that is, the deductive closure of the whole N3 graph included in the reasoning run, with the exception of the concrete application of the rule the built-in occurs in. If the scope is left open (that is, there is an unbound variable in the scope position), the reasoning scope is assumed.
3. Builtin Evaluation
3.1. Builtin theory box
A builtin statement can be seen as a constrained basic graph pattern (BGP) search on the N3 builtin theory box. This builtin theory box is defined to include all truthful builtin statements for the N3 builtin. In case this BGP search matches one or more statements in the theory box, taking into account options for datatype casting, promotion, or substitution (see Argument domains) the N3 builtin statement will be considered true.
For example, for the math:sum builtin, the builtin theory box includes all grounded builtin
statements of the form ($s.1 .. $s.n) math:sum $o ., where argument values have datatype xs:numeric and, for each statement, the sum of $s.1 .. $s.n equals $o.
Below, we give several examples of how this theory box is used to evaluate builtin
statements.
- Using the builtin statement
(1 2 3) math:sum ?x .as a BGP search on the theory box will return exactly one result where?xhas value6. - Using the concrete builtin statement
(1 2 3) math:sum 6 .as a BGP search on the theory box will similarly match exactly 1 statement.
Hence, in both cases, the builtin statement will be considered true,
and the set of matching triples from the theory box will be used to instantiate the builtin statement.
In the first case, this will lead to a single instance of the builtin statement,
where variable ?x will be bound to value 6.
In the second case, the grounded builtin statement will itself serve as such an instance.
Editors' Note:
Note that there can be multiple matching triples, thus leading to multiple instances of the builtin
statement.
Consider the following example for the list:member builtin:
( 1 2 3 ) list:member ?x .
This will yield the following matching triples from the builtin theory box:
( 1 2 3 ) list:member 1 .
( 1 2 3 ) list:member 2 .
( 1 2 3 ) list:member 3 .
The BGP search is constrained in order to avoid infinite numbers of results and
intractable calculations; in other cases, constraints weigh utility vs. difficulty
of implementation.
For example, the builtin statement (?a ?b) math:sum 2 would match an infinite
number of grounded builtin statements.
In other cases, the BGP search is restricted due to practical considerations.
For instance, builtin statement (1 ?x) math:sum 6 would match only a single grounded
builtin statement in the theory box, but this would complicate the implementation of the builtin for
only limited utility (as other builtins can be used instead to subtract 1 from 6).
These constraints are encoded in terms of argument modes and domain datatypes in the respective builtin definitions. In case these constraints are not met, the builtin statement will evaluate to false.
4. Builtins
4.1. crypto
4.1.1. crypto:sha
Gets as object the SHA-1 hash of the subject.true if and only if $o is the SHA-1 hash of $s.
Schema$s+ crypto:sha $o-
$s: xsd:stringExamples
Calculate the SHA-1 of the string "hello world".
Formula:
@prefix : <http://example.org/> .
@prefix crypto: <http://www.w3.org/2000/10/swap/crypto#> .
{ "hello world" crypto:sha ?sha . } => { :result :is ?sha . } .
Result:
@prefix : <http://example.org/>. :result :is "2aae6c35c94fcfb415dbe95f408b9ce91ee846ed" .
4.2. math
4.2.1. math:absoluteValue
Calculates as object the absolute value of the subject.true if and only if $o is the absolute value of $s.
Schema$s+ math:absoluteValue $o-
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the absolute value of the value -2.
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param -2 .
{
:Let :param ?param .
?param math:absoluteValue ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 2.
4.2.2. math:acos
Calculates the object as the arc cosine value of the subject.true if and only if $o is the arc cosine value of $s.
Schema$s? math:acos $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
4.2.3. math:asin
Calculates the object as the arc sine value of the subject.true if and only if $o is the arc sine value of $s.
Schema$s? math:asin $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the arc sine of the value 1.
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param 1 .
{
:Let :param ?param .
?param math:asin ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 1.5707963267948966 .
4.2.4. math:atan
Calculates the object as the arc tangent value of the subject.true if and only if $o is the arc tangent value of $s.
Schema$s? math:atan $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the arc tangent of the value 1.
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param 1 .
{
:Let :param ?param .
?param math:atan ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 0.7853981633974483 .
4.2.5. math:cos
Calculates the object as the cosine value of the subject.true if and only if $o is the cosine value of $s.
Schema$s? math:cos $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
4.2.6. math:cosh
Calculates the object as the hyperbolic cosine value of the subject.true if and only if $o is the hyperbolic cosine value of $s.
Schema$s? math:cosh $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the hyperbolic cosine of the value 0.
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param 0 .
{
:Let :param ?param .
?param math:cosh ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 1.0 .
4.2.7. math:degrees
Calculates the object as the value in degrees corresponding to the radians value of the subject.true if and only if $o is the value in degrees corresponding to the radians value of $s.
Schema$s? math:degrees $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the degrees of the radians value 1.57079632679.
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param 1.57079632679 .
{
:Let :param ?param .
?param math:degrees ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 89.99999999971946 .
4.2.8. math:difference
Calculates the object by subtracting the second number from the first number given in the subject list.true if and only if $o is the result of subtracting $s.2 from $s.1.
Schema( $s.1+ $s.2+ )+ math:difference $o-
$s.1: (xsd:decimal | xsd:double | xsd:float), $s.2: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
4.2.9. math:equalTo
Checks whether the subject and object are the same number.true if and only if $s is the same number as $o.
See also
math:notEqualTo
Schema$s? math:equalTo $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
4.2.10. math:exponentiation
Calculates the object as the result of raising the first number to the power of the second number in the subject list. You can also use this to calculate the logarithm of the object, with as base the first number of the subject list (see examples).true if and only if $o is the result of raising $s.1 to the power of $s.2
Schema( $s.1+ $s.2? )+ math:exponentiation $o?
$s.1: (xsd:decimal | xsd:double | xsd:float), $s.2: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the value of 7 raised to the power of 2 .
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param (7 2) .
{
:Let :param ?param .
?param math:exponentiation ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 49 .
4.2.11. math:greaterThan
Checks whether the subject is a number that is greater than the object.true if and only if $s is a number that is greater than $o.
See also
math:notGreaterThan
Schema$s+ math:greaterThan $o+
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
4.2.12. math:lessThan
Checks whether the subject is a number that is less than the object.true if and only if $s is a number that is less than $o.
See also
math:notLessThan
Schema$s+ math:lessThan $o+
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
4.2.13. math:negation
Calculates the object as the negation of the subject.true if and only if $o is the negation of $s.
Schema$s? math:negation $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the negation of the value 42 .
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param 42 .
{
:Let :param ?param .
?param math:negation ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is -42 .
4.2.14. math:notEqualTo
Checks whether the subject and object are not the same number.true if and only if $s is the not same number as $o.
See also
math:equalTo
Schema$s+ math:notEqualTo $o+
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Check if the numbers 41 and 42 are not equal .
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param (41 42) .
{
:Let :param (?X ?Y) .
?X math:notEqualTo ?Y .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.2.15. math:notGreaterThan
Checks whether the subject is a number that is not greater than the object. You can use this as an equivalent of a lessThanOrEqual operator.true if and only if $s is a number that is not greater than $o.
See also
math:greaterThan
Schema$s+ math:notGreaterThan $o+
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
4.2.16. math:notLessThan
Checks whether the subject is a number that is not less than the object. You can use this as an equivalent of a greaterThanOrEqual operator.true if and only if $s is a number that is not less than $o.
See also
math:lessThan
Schema$s+ math:notLessThan $o+
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
4.2.17. math:product
Calculates the object as the product of the numbers given in the subject list.true if and only if $o is the arithmetic product of all numbers $s.i
Schema( $s.i+ )+ math:product $o-
$s.i: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the product of 2,4,6, and 8 .
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param (2 4 6 8) .
{
:Let :param ?param .
?param math:product ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 384.
4.2.18. math:quotient
Calculates the object by dividing the first number by the second number given in the subject list.true if and only if $o is the result of dividing $s.1 by $s.2.
Schema( $s.1+ $s.2+ )+ math:quotient $o-
$s.1: (xsd:decimal | xsd:double | xsd:float), $s.2: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
4.2.19. math:remainder
Calculates the object as the remainder of the division of the first integer by the second integer given in the subject list.true if and only if $o is the remainder of dividing $s.1 by $s.2.
Schema( $s.1+ $s.2+ )+ math:remainder $o-
$s.1: xsd:integer, $s.2: xsd:integer$o: xsd:integerExamples
Calculate the remainder of 10 divided by 3.
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param (10 3) .
{
:Let :param ?param .
?param math:remainder ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 1.
4.2.20. math:rounded
Calculates the object as the integer that is closest to the subject number.true if and only if $o is the integer that is closest to $s.
If there are two such numbers, then the one closest to positive infinity is returned.
Schema$s+ math:rounded $o-
$s: (xsd:decimal | xsd:double | xsd:float)$o: xsd:integerExamples
Calculate the rounded version of 3.3.
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
:Let :param "3.3"^^xsd:double .
{
:Let :param ?param .
?param math:rounded ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 3.
4.2.21. math:sin
Calculates the object as the sine value of the subject.true if and only if $o is the sine value of $s.
Schema$s? math:sin $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the sin of pi/2 (1.57079632679) .
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
:Let :param "1.57079632679"^^xsd:double .
{
:Let :param ?param .
?param math:sin ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. @prefix xsd: <http://www.w3.org/2001/XMLSchema#> . :result :is "1.0"^^xsd:double .
4.2.22. math:sinh
Calculates the object as the hyperbolic sine value of the subject.true if and only if $o is the hyperbolic sine value of $s.
Schema$s? math:sinh $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the sinh of log(1 + sqrt(2)) (0.88137358701954302).
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
:Let :param "0.88137358701954302"^^xsd:double.
{
:Let :param ?param .
?param math:sinh ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 1.0.
4.2.23. math:sum
Calculates the object as the sum of the numbers given in the subject list.true if and only if $o is the arithmetic sum of all numbers $s.i
Schema( $s.i+ )+ math:sum $o-
$s.i: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the sum of 1,2,3,4,5,6,7,8,9,10.
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
:Let :param (1 2 3 4 5 6 7 8 9 10) .
{
:Let :param ?param .
?param math:sum ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 55.
4.2.24. math:tan
Calculates the object as the tangent value of the subject.true if and only if $o is the tangent value of $s.
Schema$s? math:tan $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the tangent of the value 0.7853981633974483 .
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
:Let :param "0.7853981633974483"^^xsd:double .
{
:Let :param ?param .
?param math:tan ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. @prefix xsd: <http://www.w3.org/2001/XMLSchema#> . :result :is "0.9999999999999999"^^xsd:double.
4.2.25. math:tanh
Calculates the object as the hyperbolic tangent value of the subject.true if and only if $o is the hyperbolic tangent value of $s.
Schema$s? math:tanh $o?
$s: (xsd:decimal | xsd:double | xsd:float)$o: (xsd:decimal | xsd:double | xsd:float)Examples
Calculate the hyperbolic tanget of 0.549306 .
Formula:
@prefix : <http://example.org/>.
@prefix math: <http://www.w3.org/2000/10/swap/math#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
:Let :param "0.549306"^^xsd:double .
{
:Let :param ?param .
?param math:tanh ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. @prefix xsd: <http://www.w3.org/2001/XMLSchema#> . :result :is "0.49999989174945103"^^xsd:double.
4.3. time
4.3.1. time:day
Gets as object the integer day component of the subject xsd:dateTime.true if and only if $o is the integer day component of $s.
Schema$s+ time:day $o-
$s: xsd:dateTime$o: xsd:integerExamples
Return the day component of the date "2023-04-01T18:06:04Z" .
Formula:
@prefix : <http://example.org/>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>.
@prefix time: <http://www.w3.org/2000/10/swap/time#> .
:Let :param "2023-04-01T18:06:04Z"^^xsd:dateTime .
{
:Let :param ?param .
?param time:day ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 1.
4.3.2. time:minute
Gets as object the integer minutes component of the subject xsd:dateTime.true if and only if $o is the integer minutes component of $s.
Schema$s+ time:minute $o-
$s: xsd:dateTime$o: xsd:integerExamples
Return the minute component of the date "2023-04-01T18:06:04Z" .
Formula:
@prefix : <http://example.org/>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>.
@prefix time: <http://www.w3.org/2000/10/swap/time#> .
:Let :param "2023-04-01T18:06:04Z"^^xsd:dateTime .
{
:Let :param ?param .
?param time:minute ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 6.
4.3.3. time:month
Gets as object the integer month component of the subject xsd:dateTime.true if and only if $o is the integer month component of $s.
Schema$s+ time:month $o-
$s: xsd:dateTime$o: xsd:integerExamples
Return the month component of the date "2023-04-01T18:06:04Z" .
Formula:
@prefix : <http://example.org/>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>.
@prefix time: <http://www.w3.org/2000/10/swap/time#> .
:Let :param "2023-04-01T18:06:04Z"^^xsd:dateTime .
{
:Let :param ?param .
?param time:month ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 4.
4.3.4. time:second
Gets as object the integer seconds component of the subject xsd:dateTime.true if and only if $o is the integer seconds component of $s.
Schema$s+ time:second $o-
$s: xsd:dateTime$o: xsd:integerExamples
Return the seconds component of the date "2023-04-01T18:06:04Z" .
Formula:
@prefix : <http://example.org/>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>.
@prefix time: <http://www.w3.org/2000/10/swap/time#> .
:Let :param "2023-04-01T18:06:04Z"^^xsd:dateTime .
{
:Let :param ?param .
?param time:second ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 4.
4.3.5. time:timeZone
Gets as object the trailing timezone offset of the subject xsd:dateTime (e.g., "-05:00").true if and only if $o is the timezone offset of $s.
Schema$s+ time:timeZone $o-
$s: xsd:dateTime$o: xsd:stringExamples
Return the time zone component of the date "2023-04-01T18:06:04Z" .
Formula:
@prefix : <http://example.org/>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>.
@prefix time: <http://www.w3.org/2000/10/swap/time#> .
:Let :param "2023-04-01T18:06:04Z"^^xsd:dateTime .
{
:Let :param ?param .
?param time:minute ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is "Z".
4.3.6. time:year
Gets as object the integer year component of the subject xsd:dateTime.true if and only if $o is the integer year component of $s.
Schema$s+ time:year $o-
$s: xsd:dateTime$o: xsd:integerExamples
Return the minute component of the date "2023-04-01T18:06:04Z" .
Formula:
@prefix : <http://example.org/>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>.
@prefix time: <http://www.w3.org/2000/10/swap/time#> .
:Let :param "2023-04-01T18:06:04Z"^^xsd:dateTime .
{
:Let :param ?param .
?param time:year ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is 2023.
4.4. list
4.4.1. list:append
Appends the lists from the subject list into a single list as object.true if and only if $o is the concatenation of all lists $s.i.
See also
list:remove
Schema( $s.i?[*] )+ list:append $o?
$s.i: rdf:List$o: rdf:ListExamples
4.4.2. list:first
Gets the first element of the subject list as object.true if and only if $s is a list and $o is the first member of that list.
See also
list:last
Schema$s+ list:first $o-
$s: rdf:ListExamples
What is the first element of ( (a) { :a :b :c } 42 )?
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
{ ( ('a') { :a :b :c } 42 ) list:first ?what . } => { :result :is ?what . } .
Result:
@prefix : <http://example.org/>.
:result :is ('a').
4.4.3. list:in
Checks whether the subject is a member of the object list.true if and only if $o is a list and $s is a member of that list.
See also
list:member
Schema$s-[*] list:in $o+
$o: rdf:ListExamples
What are the members of ( "dog" "penguin" "cat" )?
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
{ ?what list:in ( "dog" "penguin" "cat" ) . } => { :result :is ?what . } .
Result:
@prefix : <http://example.org/>. :result :is "dog" . :result :is "penguin" . :result :is "cat" .
4.4.4. list:iterate
Iterates over each member of the subject list, getting their index/value pairs as the object.true if and only if $s is a list and $o is a list with two elements: $o.1 is a valid index in list $s (index starts at 0), and $o.2 is found at that index in list $s.
Schema$s+ list:iterate ( $o.1?[*] $o.2?[*] )?[*]
$s: rdf:List$o.1: xsd:integerExamples
What is the index of "cat" in the list ("dog" "penguin" "cat")?
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
:let :param ("dog" "penguin" "cat") .
{
:let :param ?param .
?param list:iterate (?index "cat") .
}
=>
{
:result :is ?index .
} .
Result:
@prefix : <http://example.org/>. :result :is 2 .
Is "cat" the third item in the list ("dog" "penguin" "cat")?
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
:let :param ("dog" "penguin" "cat") .
{
:let :param ?param .
?param list:iterate (2 "cat") .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
Iterate over the list ("dog" "penguin" "cat").
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
{ ("dog" "penguin" "cat") list:iterate (?index ?member) . } => { :result :is (?index ?member) . } .
Result:
@prefix : <http://example.org/>. :result :is (0 "dog") . :result :is (1 "penguin") . :result :is (2 "cat") .
4.4.5. list:last
Gets the last element of the subject list as object.true if and only if $s is a list and $o is the last member of that list.
See also
list:first
Schema$s+ list:last $o-
$s: rdf:ListExamples
Test if the last element of the list (1 2 3 4) is 4.
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
:let :param (1 2 3 4).
{
:let :param ?param .
?param list:last 4 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true.
4.4.6. list:length
Gets the length of the subject list as object.true if and only if $s is a list and $o is the integer length of that list.
Schema$s+ list:length $o-
$s: rdf:ListExamples
4.4.7. list:member
Checks whether the subject list contains the object.true if and only if $s is a list and $o is a member of that list.
See also
list:in
list:memberAt
Schema$s+ list:member $o-[*]
$s: rdf:ListExamples
Determine the members of the list ("dog" "penguin" "cat").
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
{ ("dog" "penguin" "cat") list:member ?member . } => { :result :is ?member . } .
Result:
@prefix : <http://example.org/>. :result :is "dog". :result :is "penguin". :result :is "cat".
Is "cat" a member of the list ("dog" "penguin" "cat")?
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
:let :param ("dog" "penguin" "cat") .
{
:let :param ?param .
?param list:member "cat" .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true.
4.4.8. list:memberAt
Gets the member of the subject list at the given subject index as object (index starts at 0).true if and only if $s.1 is a list, $s.2 is a valid index in list $s.1, and $o is found at that index in the list.
Schema( $s.1+ $s.2?[*] )+ list:memberAt $o?[*]
$s.1: rdf:List, $s.2: xsd:integerExamples
Get the third member of the list ("dog" "penguin" "cat").
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
:let :param ("dog" "penguin" "cat").
{
:let :param ?param .
( ?param 2 ) list:memberAt ?third .
}
=>
{
:result :is ?third .
} .
Result:
@prefix : <http://example.org/>. :result :is "cat" .
Find the index of "cat" in the list ("dog" "cat" "penguin" "cat").
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
:let :param ("dog" "cat" "penguin" "cat").
{
:let :param ?param .
( ?param ?index ) list:memberAt "cat" .
}
=>
{
:result :is ?index .
} .
Result:
@prefix : <http://example.org/>. :result :is 1 . :result :is 3 .
4.4.9. list:remove
Removes each occurrence of the subject member from the subject list, and returns the resulting list as object.true if and only if $s.1 is a list, and $o is a list composed of the members of $s.1 with all occurrences of $s.2 removed (if it was present; else, $o will be the same list).
See also
list:append
Schema( $s.1+ $s.2+ )+ list:remove $o-
$s.1: rdf:ListExamples
Remove non-existent "parakeet" from the list ("dog" "penguin" "cat" "penguin").
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
:let :param ("dog" "penguin" "cat" "penguin") .
{
:let :param ?param .
( ?param "parakeet" ) list:remove ?list .
}
=>
{
:result :is ?list .
} .
Result:
@prefix : <http://example.org/>.
:result :is ("dog" "penguin" "cat" "penguin").
Remove "penguin" from the list ("dog" "penguin" "cat" "penguin").
Formula:
@prefix : <http://example.org/>.
@prefix list: <http://www.w3.org/2000/10/swap/list#> .
:let :param ("dog" "penguin" "cat" "penguin") .
{
:let :param ?param .
( ?param "penguin" ) list:remove ?list .
}
=>
{
:result :is ?list .
} .
Result:
@prefix : <http://example.org/>.
:result :is ("dog" "cat").
4.5. log
4.5.1. log:collectAllIn
Collects all values matching a given clause and adds them to a list.true if and only if, for every valid substitution of clause $s.2,
i.e., a substitution of variables with terms that generates an instance of $s.2 that is contained in the scope,
the instance of $s.1 generated by the same substitution is a member of list $s.3.
This applies scoped quantification.
Schema( $s.1- $s.2+ $s.3- )+ log:collectAllIn $o?
$s.2: log:Formula, $s.3: rdf:List$o: (Scope of the builtin. Leave as a variable to use current N3 document as scope.)Examples
Set of basic examples for log:collectAllIn.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param "Huey" .
:Let :param "Dewey" .
:Let :param "Louie" .
{
( ?param { :Let :param ?param } ?allParams ) log:collectAllIn _:x .
# Variable to be collected can also be part of a list or graph term
( (?param) { :Let :param ?param } ?nestedParams ) log:collectAllIn _:x .
# Add some extra criteria on variable values to be collected
( ?param
{
:Let :param ?param .
?param string:lessThan "Louie" .
}
?filteredParams ) log:collectAllIn _:x .
}
=>
{
:result1 :is ?allParams .
:result2 :is ?nestedParams .
:result3 :is ?filteredParams .
} .
Result:
@prefix : <http://example.org/>.
:result1 :is ("Huey" "Dewey" "Louie").
:result2 :is (("Huey") ("Dewey") ("Louie")).
:result3 :is ("Huey" "Dewey").
Example where the list is already given; in that case, the collected list will be compared with the given list.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param "Huey" .
:Let :param "Dewey" .
:Let :param "Louie" .
{
( ?param { :Let :param ?param } ("Huey" "Dewey" "Louie") ) log:collectAllIn _:x .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true
4.5.2. log:conclusion
Gets all possible conclusions from the subject graph term, including rule inferences (deductive closure), as the object graph term.true if and only if $o is the set of conclusions which can be drawn from $s (deductive closure),
by applying any rules it contains to the data it contains.
Schema$s+ log:conclusion $o?
$s: log:Formula$o: log:FormulaExamples
Draw all conclusions from the formula ":Felix a :Cat . { ?X a :Cat } => { ?X :says "Meow" . }".
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
:let :param {
:Felix a :Cat .
{ ?X a :Cat . } => { ?X :says "Meow" . } .
} .
{
:let :param ?param .
?param log:conclusion ?conclusion .
}
=>
{
:result :is ?conclusion .
} .
Result:
@prefix : <http://example.org/>.
:result :is {
:Felix a :Cat.
:Felix :says "Meow".
{ ?S a :Cat . } => { ?S :says "Meow" . } .
} .
4.5.3. log:conjunction
Merges the graph terms from the subject list into a single graph term as object.true if and only if $o is a graph term that is the logical conjunction of each of the graph terms $s.i (i.e., includes all their triples, removing any duplicates) .
Schema( $s.i+ )+ log:conjunction $o?
$s.i: log:Formula$o: log:FormulaExamples
Merge the formulas "{ :Felix a :Cat . }" , "{ :Pluto a :Dog . }", "{ :Pingu a :Penguin . }" .
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
( { :Felix a :Cat . }
{ :Pluto a :Dog . }
{ :Pingu a :Penguin . }
) log:conjunction ?merged .
}
=>
{
:result :is ?merged .
} .
Result:
@prefix : <http://example.org/>.
:result :is {
:Felix a :Cat .
:Pingu a :Penguin .
:Pluto a :Dog .
} .
4.5.4. log:content
Dereferences the subject IRI and retrieves the online resource as the object string.true if and only if $o is a string that represents the online resource to which $s is dereferenced.
Schema$s+ log:content $o?
$s: log:Uri$o: xsd:stringExamples
Fetch the content of https://www.w3.org/People/Berners-Lee/card.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
<https://www.w3.org/People/Berners-Lee/card> log:content ?content .
}
=>
{
:result :is ?content .
} .
Result:
:result :is "...the content of https://www.w3.org/People/Berners-Lee/card ...".
4.5.5. log:dtlit
Creates a datatyped literal as object, based on the string value and datatype IRI in the subject list.true if and only if $o is a datatyped literal with string value corresponding to $s.1 and datatype IRI corresponding to $s.2.
See also
log:langlit
Schema( $s.1? $s.2? )? log:dtlit $o?
$s.1: xsd:string, $s.2: log:Uri$o: log:LiteralExamples
Parse the datatyped literal "1971-05-05"^^xsd:date into a string and data type IRI.
Formula:
@prefix : <http://example.org/>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
( ?string ?type ) log:dtlit "1971-05-05"^^xsd:date .
}
=>
{
:result :is ( ?string ?type ) .
} .
Result:
@prefix : <http://example.org/>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
:result :is ("1971-05-05" xsd:date).
Create a datatyped literal from the string "1971-05-05" and the type xsd:date.
Formula:
@prefix : <http://example.org/>.
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{ ( "1971-05-05" xsd:date ) log:dtlit ?typed } => { :result :is ?typed . } .
Result:
@prefix : <http://example.org/>. @prefix xsd: <http://www.w3.org/2001/XMLSchema#> . :result :is "1971-05-05"^^xsd:date.
4.5.6. log:equalTo
Checks whether the subject and object N3 terms are the same (comparison occurs on the syntax level). Can also be used to bind values to variables (see examples).true if and only if $s and $o are the same N3 term.
Not to be confused with owl:sameAs.
Literals will be compared exactly: their datatypes must be identical (in case of strings, language tags must be identical).
See also
log:notEqualTo
Schema$s? log:equalTo $o?
Examples
Determine if 1 is equal to 1 and "Cat" is equal to "Cat" and { :A :B :C . :D :E :F } is equal to { :D :E :F . :A :B :C }.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
1 log:equalTo 1 .
"Cat" log:equalTo "Cat" .
{ :A :B :C . :D :E :F . } log:equalTo { :D :E :F . :A :B :C . } .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true.
Determine
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
<http://famous.web.site> owl:sameAs <http://mirror.famous.web.site> .
{
<http://famous.web.site> log:equalTo <http://famous.web.site> .
# But not
#
# <http://famous.web.site> log:equalTo <http://mirror.famous.web.site> .
#
# and not
#
# <http://famous.web.site#123> log:equalTo <http://famous.web.site> .
#
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true.
Assign values from the object list to universal variables given in the subject list. This can be compared to "destructuring" or "unpacking" in programming languages such as JavaScript or Python. In contrast to those languages, however, it works in either direction in N3. This mechanism works because an effort is made to ensure the truthfulness of builtin statements in N3.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
( "War and Peace" "Leo Tolstoy" 1225 ) log:equalTo ( ?title ?author ?numPages ) .
}
=>
{
:result :is ?title , ?author , ?numPages .
} .
Result:
@prefix : <http://example.org/>. :result :is "War and Peace" , "Leo Tolstoy" , 1225 . # objects can be in any order
Assign values from the object list to universal variables given in the subject list. This can be compared to "destructuring" or "unpacking" in programming languages such as JavaScript or Python. In contrast to those languages, however, it works in either direction in N3. This mechanism works because an effort is made to ensure the truth of builtin statements in N3.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
( ?x ?y ?z ) log:equalTo ( 1 2 3 )
}
=>
{
:result :is ?x , ?y , ?z .
} .
Result:
@prefix : <http://example.org/>. :result :is 1 , 2 , 3 . # objects can be in any order
Assign a value to an existential or universal variable.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
_:x log:equalTo 42 .
?q log:equalTo "Cat"@en .
# This will fail because _:x is already assigned to 42 .
# _:x log:equalTo 17 .
}
=>
{
:result :is ?q .
} .
Result:
@prefix : <http://example.org/>. :result :is "Cat"@en .
4.5.7. log:forAllIn
Two clauses are given in the subject list: for every match of the first clause, the builtin checks whether the second clause also holds for that match.true if and only if, for every valid substitution of clause $s.1,
i.e., a substitution of variables with terms that generates an instance of $s.1 that is contained in the scope,
the instance of $s.2 generated by the same substitution is also contained in the scope.
This applies a scoped quantification.
Schema( $s.1+ $s.2+ )+ log:forAllIn $o?
$s.1: log:Formula, $s.2: log:Formula$o: (Scope of the builtin. Leave as a variable to use current N3 document as scope.)Examples
For each subtask of a composite task, check whether the subtask is completed.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
:c a :CompositeTask ;
:subTask :s1 , :s2 , :s3 .
:s1 :state :Completed .
:s2 :state :Completed .
:s3 :state :Completed .
{
?c a :CompositeTask .
( { ?c :subTask ?s } { ?s :state :Completed } ) log:forAllIn _:t .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true.
4.5.8. log:includes
Checks whether the subject graph term includes the object graph term (taking into account variables). Can also be used to bind variables to values within the graph contents (see examples).true if and only if there exists some substitution which, when applied to $s and $o,
creates graph terms $s' and $o' such that every statement in $o' is also in $s''.
Variable substitution is applied recursively to nested compound terms such as graph terms and lists.
See also
log:notIncludes
Schema$s+ log:includes $o+
$s: log:Formula(Can also be left as a variable to use current N3 document as scope.)
$o: log:FormulaExamples
Check whether the current N3 document includes { ?X a :Cat }.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
:Felix a :Cat .
:Tom a :Cat .
:Rex a :Dog .
{
_:t log:includes { ?X a :Cat } .
}
=>
{
:result :is ?X .
} .
Result:
@prefix : <http://example.org/>. @prefix log: <http://www.w3.org/2000/10/swap/log#>. :result :is :Felix. :result :is :Tom.
Check whether the formula { :Felix a :Cat } includes { ?X a :Cat }.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
{ :Felix a :Cat } log:includes { ?X a :Cat } .
}
=>
{
:result :is ?X .
} .
Result:
@prefix : <http://example.org/>. :result :is :Felix .
4.5.9. log:langlit
Creates a language-tagged literal as object, based on the string value and language tag (see BCP47) in the subject list.true if and only if $o is a language-tagged literal with string value corresponding to $s.1 and language tag corresponding to $s.2. $s.2 should be a string in the form of a BCP47 language tag.
See also
log:dtlit
Schema( $s.1? $s.2? )? log:langlit $o?
$s.1: xsd:string, $s.2: xsd:string$o: log:LiteralExamples
4.5.10. log:notEqualTo
Checks whether the subject and object N3 terms are _not_ the same (comparison occurs on the syntax level).true if and only if $s and $o are _not_ the same N3 term.
See also
log:equalTo
Schema$s+ log:notEqualTo $o+
Examples
Check whether two graph terms, one containing a universal variable, are not equal.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
{ :A :B :C . } log:notEqualTo { :A :B ?c } .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. # no result (?c can be unified with :C)
Determine if 1 is not equal to 2 and "Cat" is not equal to "CAT" and { :A :B :C . } is not equal to { :C :B :A }.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
1 log:notEqualTo 2 .
"Cat" log:notEqualTo "CAT" .
{ :A :B :C . } log:notEqualTo { :C :B :A . } .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
Check if an existential or universal variable is not equal to a value.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
_:x log:notEqualTo 42 .
?q log:notEqualTo "Cat"@en .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. # no result (the variables _:x and ?q are not bounded)
4.5.11. log:notIncludes
Checks whether the subject graph term _does not_ include the object graph term (taking into account variables)true if and only if $s log:includes $o is false.
See also
log:includes
Schema$s+ log:notIncludes $o+
$s: log:Formula$o: log:FormulaExamples
Check whether the formula { :a :b :c } does not include { :a :b :d }.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
# Dynamic evaluation of ?X and ?Y
?X log:notIncludes ?Y .
?X log:equalTo { :a :b :c }.
?Y log:equalTo { :a :b :d }.
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true.
Check whether the formula { :Felix a :Cat } does not include { ?X :eats ?Y }.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
{ :Felix a :Cat } log:notIncludes { ?X :eats ?Y } .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true.
4.5.12. log:outputString
The N3 reasoner will print the object strings in the order of the subject keys, instead of printing the derivations or deductive closure. This may require a reasoner flag to be set.The concrete semantics of this builtin (e.g., which N3 resource types are supported) will depend on the N3 reasoner.
Schema$s+ log:outputString $o+
$o: xsd:stringExamples
Print the two string "This is the first line " , "This is the second line " to the output.
Formula:
@prefix : <http://example.org/>. @prefix log: <http://www.w3.org/2000/10/swap/log#> . _:2 log:outputString "This is the second line\n" . _:1 log:outputString "This is the first line\n" .
Result:
# If the reasoner support the outputString options This is the first line This is the second line
4.5.13. log:parsedAsN3
Parses the subject string into an object graph term.true if and only if $s, when parsed as N3, gives $o. $s should be a syntactically valid string in N3 format.
See also
log:semantics
Schema$s+ log:parsedAsN3 $o-
$s: xsd:string(should be a syntactically valid string in N3 format)
$o: log:FormulaExamples
Parse the string ':Socrates a :Human .' as N3.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
:Let :param """
@prefix : <urn:example:> .
:Socrates a :Human .
""" .
{
:Let :param ?X .
?X log:parsedAsN3 ?Y .
}
=>
{
:result :is ?Y .
} .
Result:
@prefix : <http://example.org/>.
:result :is { <urn:example:Socrates> a <urn:example:Human> . } .
4.5.14. log:rawType
Gets the type of the N3 resource.true if and only if the N3 resource type of $s is $o.
N3 resource types include log:Formula, log:Literal, rdf:List or log:Other.
Schema$s+ log:rawType $o-
$o: log:UriExamples
Get the type of lists and graph terms.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
(1 2 3 4) log:rawType ?listType .
{ :s :p :o } log:rawType ?graphType .
}
=>
{
:result :is ( ?listType ?graphType ) .
} .
Result:
@prefix : <http://example.org/>. @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>. @prefix log: <http://www.w3.org/2000/10/swap/log#> . :result :is ( rdf:List log:Formula ) .
Get the type of literal resources.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
"Hello" log:rawType ?stringType .
42 log:rawType ?integerType .
true log:rawType ?trueType .
false log:rawType ?falseType .
}
=>
{
:result :is ( ?stringType ?integerType ?trueType ?falseType ) .
} .
Result:
@prefix : <http://example.org/>. @prefix log: <http://www.w3.org/2000/10/swap/log#> . :result :is ( log:Literal log:Literal log:Literal log:Literal ) .
Get the type of resources.
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{
<http://www.w3c.org> log:rawType ?resourceType .
}
=>
{
:result :is ?resourceType .
} .
Result:
@prefix : <http://example.org/>. @prefix log: <http://www.w3.org/2000/10/swap/log#> . :result :is log:Other.
4.5.15. log:semantics
Gets as object the graph term that results from parsing an online (N3) string, found by dereferencing the subject IRI.true if and only if $o is a graph term that results from parsing the string that results from dereferencing $s.
Schema$s+ log:semantics $o?
$s: log:Uri$o: log:FormulaExamples
Read the contents of the file <semantics.data> and parse it as Notation3.
We assume <semantics.data> contains the text:
@prefix : <http://example.org/>. :Socrates a :Human .
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{ <semantics.data> log:semantics ?semantics . } => { :result :is ?semantics } .
Result:
@prefix : <http://example.org/>.
:result :is { :Socrates a :Human . } .
4.5.16. log:semanticsOrError
Either gets as object the graph term that results from parsing an online (N3) string, found by dereferencing the subject IRI; or an error message that explains what went wrong.true if and only if (a) $o is a graph term that results from parsing the string that results from dereferencing $s; or (b) an error message explaining what went wrong.
Schema$s+ log:semanticsOrError $o?
$s: log:Uri$o: (either a log:Formula or xsd:string)Examples
Read the contents a non existing <error.data> and parse it as Notation3 (which of course will fail).
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{ <error.data> log:semanticsOrError ?semantics } => { :result :is ?semantics } .
Result:
@prefix : <http://example.org/>. :result :is "error(existence_error(source_sink,/error.data),context(system:open/4,No such file or directory))" .
4.5.17. log:skolem
Gets as object a skolem IRI that is a function of the subject (commonly a list) and a concrete reasoning run (implicit); for one reasoning run, the same subject will always result in the same skolem IRI.true if and only if $o is a skolem IRI that is produced by applying a skolem function to the subject.
Schema$s+ log:skolem $o-
Examples
Generate a unique Skolem IRI from the list (:abc 77 "xyz") .
Formula:
@prefix : <http://example.org/>.
@prefix log: <http://www.w3.org/2000/10/swap/log#> .
{ (:abc 77 "xyz") log:skolem ?skolem . } => { :result :is ?skolem } .
Result:
@prefix : <http://example.org/>. :result :is <http://www.w3.org/2000/10/swap/genid#zmgk3Vt_z_u7FQlk1NmqIw> .
4.5.18. log:uri
Gets as object the string representation of the subject URI.true if and only if $o is the string representation of $s.
Schema$s? log:uri $o?
$s: (a URI)$o: xsd:stringExamples
4.6. string
4.6.1. string:concatenation
Concatenates the strings from the subject list into a single string as object.true if and only if the string concatenation of $s.i equals $o.
Schema( $s.i+ )+ string:concatenation $o-
$s.i: xsd:string$o: xsd:stringExamples
Concatenates the string "hello", " " and "world!".
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param ( "hello" " " "world!" ) .
{
:Let :param ?param .
?param string:concatenation ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is "hello world!".
4.6.2. string:contains
Checks whether the subject string contains the object string.true if and only if $s contains $o.
See also
string:containsIgnoringCase
Schema$s+ string:contains $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "hello world!" contains the string "llo worl".
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "hello world!" .
:Let :param2 "llo worl".
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:contains ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.3. string:containsIgnoringCase
Checks whether the subject string contains the object string, ignoring differences between lowercase and uppercase.true if and only if $s contains $o when ignoring case differences.
See also
string:contains
Schema$s+ string:containsIgnoringCase $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "hello world!" contains the string "lLO woRl".
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "hello world!" .
:Let :param2 "lLO woRl".
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:containsIgnoringCase ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.4. string:endsWith
Checks whether the subject string ends with the object string.true if and only if $s ends with $o.
Schema$s+ string:endsWith $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "hello world!" ends with "orld!".
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "hello world!" .
:Let :param2 "orld!".
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:endsWith ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.5. string:equalIgnoringCase
Checks whether the subject string is the same as the object string, ignoring differences between lowercase and uppercase.true if and only if $s is the same string as $o when ignoring case differences.
Schema$s+ string:equalIgnoringCase $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "hello world!" is equal to "hELLo wORld!" ignoring the case .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "hello world!" .
:Let :param2 "hELLo wORld!" .
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:equalIgnoringCase ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.6. string:format
Calculates the object as the result of replacing the tags in the first string from the subject list with the remaining strings from the subject list. See C’s sprintf function for details on these tags.true if and only if $o is the result of replacing the tags found in $s.(i=1) with the strings $s.(i>1)
Schema( $s.i+ )+ string:format $o-
$s.i: xsd:string$o: xsd:stringExamples
Calculate the result of applying the format "%s://%s/%s" to the strings "https", "w3c.github.io" and "N3/spec" .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param ( "%s://%s/%s" "https" "w3c.github.io" "N3/spec/" ) .
{
:Let :param ?param .
?param string:format ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is "https://w3c.github.io/N3/spec/".
4.6.7. string:greaterThan
Checks whether the subject string is greater than the object string, according to Unicode code order.true if and only if $s is greater than $o as per the Unicode code order.
See also
string:notGreaterThan
Schema$s+ string:greaterThan $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "Pengiun" is greater than the string "Cat" .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "Penguin" .
:Let :param2 "Cat".
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:greaterThan ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.8. string:lessThan
Checks whether the subject string is less than the object string, according to Unicode code order.true if and only if $s is less than $o as per the Unicode code order.
See also
string:notLessThan
Schema$s+ string:lessThan $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "Cat" is less than the string "Penguin" .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "Cat" .
:Let :param2 "Penguin".
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:lessThan ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.9. string:matches
Checks whether the subject string matches the object regular expression. The regular expression follows the perl, python style.true if and only if string $s matches the regular expression $o
See also
string:notMatches
Schema$s+ string:matches $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "hello world!" matches the regular expression ".(l)+o wo.".
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "hello world!" .
:Let :param2 ".*(l)+o wo.*".
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:matches ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.10. string:notEqualIgnoringCase
Checks whether the subject string is not the same as the object string, ignoring differences between lowercase and uppercase.true if and only if $s is not the same string as $o when ignoring case differences.
Schema$s+ string:notEqualIgnoringCase $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "hello world!" is not equal to "hELLo dunia!" ignorning the case .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "hello world!" .
:Let :param2 "hELLo dunia!" .
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:notEqualIgnoringCase ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.11. string:notGreaterThan
Checks whether the subject string is not greater than the object string, according to Unicode code order. You can use this as an equivalent of a lessThanOrEqual operator.true if and only if $s is not greater than $o as per the Unicode code order.
See also
string:greaterThan
Schema$s+ string:notGreaterThan $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "Cat" is not greater than the string "Penguin" .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "Cat" .
:Let :param2 "Penguin".
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:notGreaterThan ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.12. string:notLessThan
Checks whether the subject string is not less than the object string, according to Unicode code order. You can use this as an equivalent of a greaterThanOrEqual operator.true if and only if $s is not less than $o as per the Unicode code order.
See also
string:lessThan
Schema$s+ string:notLessThan $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "Penguin" is not less than the string "Cat" .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "Penguin".
:Let :param2 "Cat" .
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:notLessThan ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.13. string:notMatches
Checks whether the subject string does not match the object regular expression. The regular expression follows the perl, python style.true if and only if string $s does not match the regular expression $o
See also
string:matches
Schema$s+ string:notMatches $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "hello world!" no matches the regular expression ".(l)+o dunia.".
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "hello world!" .
:Let :param2 ".*(l)+o dunia.*".
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:notMatches ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
4.6.14. string:replace
Calculates the object as the result of, given the strings in the subject list, replacing all occurrences of the second string in the first string with the third string.true if and only if $o is the result of replacing all occurrences of $s.2 in $s.1 with $s.3
Schema( $s.1+ $s.2+ $s.3+ )+ string:replace $o-
$s.1: xsd:string, $s.2: xsd:string, $s.3: xsd:string$o: xsd:stringExamples
Replace all "l"-s in the string "hello world!" with the bracket version "[l]" .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :data "hello world!" .
:Let :search "(l)" .
:Let :replace "[$1]" .
{
:Let :data ?data .
:Let :search ?search .
:Let :replace ?replace .
(?data ?search ?replace) string:replace ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is "he[l][l]o wor[l]d!".
4.6.15. string:scrape
Calculates the object as the first matching group when, given the subject list, matching the second string as regular expression (with exactly 1 group) against the first string.true if and only if $o is the first matching group when matching $s.2 as a regular expression against $s.1
Schema( $s.1+ $s.2+ )+ string:scrape $o-
$s.1: xsd:string, $s.2: xsd:string$o: xsd:stringExamples
Extract from the string "https://w3c.github.io/N3/spec/" the last path element using a regular expression .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "https://w3c.github.io/N3/spec/" .
:Let :param2 ".*/([^/]+/)$" .
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
(?param1 ?param2) string:scrape ?result .
}
=>
{
:result :is ?result .
} .
Result:
@prefix : <http://example.org/>. :result :is "spec/".
4.6.16. string:startsWith
Checks whether the subject string starts with the object string.true if and only if $s starts with $o.
Schema$s+ string:startsWith $o+
$s: xsd:string$o: xsd:stringExamples
Checks whether the string "hello world!" starts with "hello" .
Formula:
@prefix : <http://example.org/>.
@prefix string: <http://www.w3.org/2000/10/swap/string#> .
:Let :param1 "hello world!" .
:Let :param2 "hello".
{
:Let :param1 ?param1 .
:Let :param2 ?param2 .
?param1 string:startsWith ?param2 .
}
=>
{
:result :is true .
} .
Result:
@prefix : <http://example.org/>. :result :is true .
5. Acknowledgements
In addition to the editors, the following people have contributed to this specification: Dörthe Arndt, Pierre-Antoine Champin, and Jos De Roo.