From 8390906e3c2634bb67e9f2b1f48b269218b55559 Mon Sep 17 00:00:00 2001 From: Andy Seaborne Date: Fri, 27 Dec 2024 09:08:39 +0000 Subject: [PATCH] GH-154: Functions for the base direction feature Co-authored-by: Thomas Tanon Co-authored-by: Olaf Hartig --- spec/index.html | 376 ++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 351 insertions(+), 25 deletions(-) diff --git a/spec/index.html b/spec/index.html index 8d51a6b..daa397e 100644 --- a/spec/index.html +++ b/spec/index.html @@ -6145,10 +6145,10 @@
isNUMERIC
STR
-xsd:string  STR (literal ltrl)
+xsd:string  STR (literal literal)
 xsd:string  STR (IRI rsrc)
-

Returns the lexical form of ltrl (a +

Returns the lexical form of literal (a literal); returns the codepoint representation of rsrc (an IRI). This is useful for examining parts of an IRI, for instance, the host-name.

@@ -6238,16 +6238,205 @@
LANG
+ +

+ Function examples: +

+
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
ExpressionResult
LANG("abc"@en)"en"
LANG("abc"@en--ltr)"en"
LANG("abc")""
LANG(1)""
LANG(<http://example/>)error
+
+ +
+
LANGDIR
+ 
 xsd:string  LANGDIR (literal ltrl)
+
+

+ If the argument is a literal with rdf:dirLangString + as its datatype IRI, + the function LANGDIR returns the + base direction + of this literal. + Otherwise, the function returns the empty string. +

+
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
ExpressionResult
LANGDIR("abc"@en--ltr)"ltr"
LANGDIR("abc"@en)""
LANGDIR("abc")""
LANGDIR(1)""
LANGDIR(<http://example/>)error
+
+
+ +
+
hasLANG
+ 
 xsd:string  hasLANG (RDF term term)
+
+

+ The function `hasLANG` returns true if the + argument is a literal with a language + tag. Otherwise, the function returns false. +

+

If the argument is a literal, the function is equivalent to + testing for the datatype of the literal being either + `rdf:langString` or `rdf:dirLangString`. +

+
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
ExpressionResult
hasLANG("abc"@en)true
hasLANG("abc@"en--ltr)true
hasLANG("تصميم المواقع"@ar--rtl)true
hasLANG(1)false
hasLANG(<http://example/>)false
+
+
+ +
+
hasLANGDIR
+ 
 xsd:string  hasLANGDIR (RDF term term)
+
+

+ The function `hasLANGDIR` returns true if the + argument is a literal with a language tag and a base direction. + Otherwise, the function returns false. +

+

If the argument is a literal, the function is equivalent to + testing for the datatype of the literal being + `rdf:dirLangString`. +

+
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
ExpressionResult
hasLANGDIR("abc"@en)false
hasLANGDIR("abc@"en--ltr)true
hasLANGDIR("تصميم المواقع"@ar--rtl)true
hasLANGDIR(1)false
hasLANGDIR(<http://example/>)false
+
+
+
DATATYPE
 iri  DATATYPE (literal literal)
-

Returns the datatype IRI of a - literal.

-

- The datatype of a literal with a language tag is rdf:langString. -

+

Returns the datatype IRI of + the given literal.

+
+

+ The datatype IRI of a literal with a + language tag + and no base direction + is rdf:langString. +

+

+ The datatype IRI of a literal with a + language tag + and a + base direction + is rdf:dirLangString. +

+ 
 PREFIX foaf:       <http://xmlns.com/foaf/0.1/>
@@ -6336,13 +6525,24 @@ 
BNODE

             
This functionality is compatible with the treatment of
                 blank nodes in SPARQL CONSTRUCT templates.
+
STRDT
literal  STRDT(xsd:string lexicalForm, IRI datatypeIRI)
-

The STRDT function constructs a literal with lexical form and type as - specified by the arguments.

+

The STRDT function constructs a literal with + lexical form + and + datatype IRI + as specified by the arguments. +

+ + + + + + @@ -6355,23 +6555,108 @@
STRDT
ExpressionResult
STRDT("123", xsd:integer)
+
+ `STRDT` should not be called with `datatypeIRI` argument + `rdf:langString` or `rdf:dirLangString`. To create literals with + these IRIs as datatype IRI, function `STRLANG` + or `STRLANGDIR` should be used. +
+
STRLANG
literal  STRLANG(xsd:string lexicalForm, xsd:string langTag)
-

The STRLANG function constructs a literal with lexical form and language - tag as specified by the arguments.

+

The STRLANG function constructs a literal with + lexical form + and + language tag + as specified by the arguments. +

+

+ The argument `langTag` MUST not be an empty string and SHOULD be a + a valid language tag. +

+ + + + + + - - + + - -
ExpressionResult
STRLANG("chat", "en")"chat"@enSTRLANG("chat", "fr")"chat"@fr
-
+ + STRLANG("abc", "") + error + + + STRLANG(123, "en") + error + + + +
+ +
+
STRLANGDIR
+ 
literal  STRLANGDIR(xsd:string lexicalForm, xsd:string langTag, xsd:string baseDirection)
+

+ The STRLANGDIR function constructs a literal with + lexical form, + language tag and + base direction + as specified by the arguments. +

+

+ The argument `langTag` MUST not be an empty string and SHOULD be a + a valid language tag. + The argument `baseDirection` MUST be either `"ltr"` or `"rtl"`. +

+
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
ExpressionResult
STRLANGDIR("abc", "en", "ltr")"abc"@en--ltr
STRLANGDIR("abc", "en", "LTR")error
STRLANGDIR("قطة", "ar", "rtl")"قطة"@ar--rlt
STRLANGDIR("abc", "en", "")error
STRLANGDIR("abc", "", "ltr")error
STRLANGDIR(123, "", "ltr")error
STRLANGDIR(<x:uri>, "en", "ltr")error
+
UUID
iri  UUID()
@@ -6415,7 +6700,7 @@
Strings in SPARQL Functions
String arguments

Certain functions (e.g., REGEX, STRLEN, CONTAINS) take a string literal as an argument and accept a literal with datatype xsd:string, or a literal with a - language tag. They then act on the lexical form + language tag. They then act on the lexical form of the literal.

The term string literal is used in the function descriptions for this. Use of any other RDF term will cause a call to the function to raise an error.

@@ -6431,9 +6716,27 @@
Argument Compatibility Rules
functions raises an error.

Compatibility of two arguments is defined as:

    -
  • The arguments are literals with datatype xsd:string
    • -
  • The arguments are literals with identical language tags
    • -
  • The first argument is a literal with a language tag and the second argument is a literal with datatype xsd:string
    • +
  • + The arguments are literals with datatype xsd:string +
    • +
  • + The arguments are literals with datatype rdf:langString + and the same language tags +
    • +
  • + The arguments are literals with datatype rdf:dirLangString + and the same + language tag + and base direction +
    • +
  • + The first argument is a literal with datatype rdf:langString + and the second argument is a literal with datatype xsd:string +
    • +
  • + The first argument is a literal with datatype rdf:dirLangString, + and the second argument has datatype xsd:string +
@@ -6470,9 +6773,24 @@
Argument Compatibility Rules
+ + + + + + + + + + + + + + +
"abc""b"@en--ltrno
"abc"@en--ltr"b"@en--ltryes
"abc"@en--ltr "b"@en no
"abc"@en--ltr"z"yes
@@ -6485,7 +6803,11 @@
Argument Compatibility Rules
String Literal Return Type

Functions that return a string literal do so with the string literal of the same - kind as the first argument (literal with datatype xsd:string, literal with the same language tag). + kind as the first argument (literal with datatype xsd:string, literal + with the same + language tag + and optional + base direction). This includes SUBSTR, STRBEFORE and STRAFTER.

The function CONCAT returns a string literal based on the @@ -6498,7 +6820,8 @@

STRLEN

The strlen function corresponds to the XPath fn:string-length function and returns an - xsd:integer equal to the length in characters of the lexical form of the + xsd:integer equal to the length in characters of the + lexical form of the literal.

@@ -6528,8 +6851,10 @@
SUBSTR

The substr function corresponds to the XPath fn:substring function and returns a literal of the same kind (literal with datatype xsd:string, literal with the same language tag) - as the source input parameter but with a lexical form derived from - the substring of the lexical form of the source.

+ as the source input parameter but with a + lexical form + derived from the substring of the lexical form of the source. +

The arguments startingLoc and length may be derived types of xsd:integer.

The index of the first character in a strings is 1.

@@ -11862,10 +12187,11 @@

Changes between SPARQL 1.1 Query Language and SPARQL 1.2 Query Language

  • Remove concepts of plain and simple literals, in favor of explicit mentions of xsd:string
  • Update grammar for triple terms, reifiers, reified triples, annotation syntax, and triple term functions in
    • -
  • Update grammar for initial text direction syntax and functions in
    • +
  • Update grammar for literal base direction syntax and functions in
  • Migrate XML Schema references to 1.1
  • Update references to XPath from 2.0 to 3.1
  • Add functions on triple terms to
    • +
  • Add functions related to base direction and language tag `LANGDIR`, `hasLANG`, hasLANGDIR, `STRLANGDIR`