/** Implementation of node-centric functions. */
public class NodeFunctions {
private static final NodeValue xsdString = NodeValue.makeNode(XSD.xstring.asNode());
// -------- sameTerm
public static NodeValue sameTerm(NodeValue nv1, NodeValue nv2) {
return NodeValue.booleanReturn(sameTerm(nv1.asNode(), nv2.asNode()));
}
public static boolean sameTerm(Node n1, Node n2) {
if (n1.equals(n2)) return true;
if (n1.isLiteral() && n2.isLiteral()) {
// But language tags are case insensitive.
String lang1 = n1.getLiteralLanguage();
String lang2 = n2.getLiteralLanguage();
if (!lang1.equals("") && lang1.equalsIgnoreCase(lang2)) {
// Two language tags, equal by case insensitivity.
boolean b = n1.getLiteralLexicalForm().equals(n2.getLiteralLexicalForm());
if (b) return true;
}
}
return false;
}
// -------- RDFterm-equals
public static NodeValue rdfTermEquals(NodeValue nv1, NodeValue nv2) {
return NodeValue.booleanReturn(rdfTermEquals(nv1.asNode(), nv2.asNode()));
}
// Exact as defined by SPARQL spec.
public static boolean rdfTermEquals(Node n1, Node n2) {
if (n1.equals(n2)) return true;
if (n1.isLiteral() && n2.isLiteral()) {
// Two literals, may be sameTerm by language tag case insensitivity.
String lang1 = n1.getLiteralLanguage();
String lang2 = n2.getLiteralLanguage();
if (!lang1.equals("") && lang1.equalsIgnoreCase(lang2)) {
// Two language tags, equal by case insensitivity.
boolean b = n1.getLiteralLexicalForm().equals(n2.getLiteralLexicalForm());
if (b) return true;
}
// Two literals, different terms, different language tags.
NodeValue.raise(new ExprEvalException("Mismatch in RDFterm-equals: " + n1 + ", " + n2));
}
// One or both not a literal.
return false;
}
// -------- str
public static NodeValue str(NodeValue nv) {
return NodeValue.makeString(str(nv.asNode()));
}
public static String str(Node node) {
if (node.isLiteral()) return node.getLiteral().getLexicalForm();
if (node.isURI()) return node.getURI();
// if ( node.isBlank() ) return node.getBlankNodeId().getLabelString() ;
// if ( node.isBlank() ) return "" ;
if (node.isBlank()) NodeValue.raise(new ExprTypeException("Blank node: " + node));
NodeValue.raise(new ExprEvalException("Not a string: " + node));
return "[undef]";
}
// -------- datatype
public static NodeValue datatype(NodeValue nv) {
return NodeValue.makeNode(datatype(nv.asNode()));
}
public static Node datatype(Node node) {
if (!node.isLiteral()) {
NodeValue.raise(new ExprTypeException("datatype: Not a literal: " + node));
return null;
}
String s = node.getLiteralDatatypeURI();
boolean plainLiteral = (s == null || s.equals(""));
if (plainLiteral) {
boolean simpleLiteral =
(node.getLiteralLanguage() == null || node.getLiteralLanguage().equals(""));
if (!simpleLiteral)
NodeValue.raise(new ExprTypeException("datatype: Literal has language tag: " + node));
return XSD.xstring.asNode();
}
return Node.createURI(s);
}
// -------- lang
public static NodeValue lang(NodeValue nv) {
return NodeValue.makeString(lang(nv.asNode()));
}
public static String lang(Node node) {
if (!node.isLiteral())
NodeValue.raise(
new ExprTypeException("lang: Not a literal: " + FmtUtils.stringForNode(node)));
String s = node.getLiteralLanguage();
if (s == null) s = "";
return s;
}
// -------- langMatches
public static NodeValue langMatches(NodeValue nv, NodeValue nvPattern) {
return langMatches(nv, nvPattern.getString());
}
public static NodeValue langMatches(NodeValue nv, String langPattern) {
Node node = nv.asNode();
if (!node.isLiteral()) {
NodeValue.raise(new ExprTypeException("langMatches: not a literal: " + node));
return null;
}
String nodeLang = node.getLiteralLexicalForm();
if (langPattern.equals("*")) {
if (nodeLang == null || nodeLang.equals("")) return NodeValue.FALSE;
return NodeValue.TRUE;
}
// See RFC 3066 (it's "tag (-tag)*)"
String[] langElts = nodeLang.split("-");
String[] langRangeElts = langPattern.split("-");
/*
* Here is the logic to compare language code.
* There is a match if the language matches the
* parts of the pattern - the language may be longer than
* the pattern.
*/
/* RFC 4647 basic filtering.
*
* To do extended:
* 1. Remove any -*- (but not *-)
* 2. Compare primary tags.
* 3. Is the remaining range a subsequence of the remaining language tag?
*/
// // Step one: remove "-*-" (but not "*-")
// int j = 1 ;
// for ( int i = 1 ; i < langRangeElts.length ; i++ )
// {
// String range = langRangeElts[i] ;
// if ( range.equals("*") )
// continue ;
// langRangeElts[j] = range ;
// j++ ;
// }
//
// // Null fill any free space.
// for ( int i = j ; i < langRangeElts.length ; i++ )
// langRangeElts[i] = null ;
// This is basic specific.
if (langRangeElts.length > langElts.length)
// Lang tag longer than pattern tag => can't match
return NodeValue.FALSE;
for (int i = 0; i < langRangeElts.length; i++) {
String range = langRangeElts[i];
if (range == null) break;
// Language longer than range
if (i >= langElts.length) break;
String lang = langElts[i];
if (range.equals("*")) continue;
if (!range.equalsIgnoreCase(lang)) return NodeValue.FALSE;
}
return NodeValue.TRUE;
}
// -------- isURI/isIRI
public static NodeValue isIRI(NodeValue nv) {
return NodeValue.booleanReturn(isIRI(nv.asNode()));
}
public static boolean isIRI(Node node) {
if (node.isURI()) return true;
return false;
}
public static NodeValue isURI(NodeValue nv) {
return NodeValue.booleanReturn(isIRI(nv.asNode()));
}
public static boolean isURI(Node node) {
return isIRI(node);
}
// -------- isBlank
public static NodeValue isBlank(NodeValue nv) {
return NodeValue.booleanReturn(isBlank(nv.asNode()));
}
public static boolean isBlank(Node node) {
return node.isBlank();
}
// -------- isLiteral
public static NodeValue isLiteral(NodeValue nv) {
return NodeValue.booleanReturn(isLiteral(nv.asNode()));
}
public static boolean isLiteral(Node node) {
return node.isLiteral();
}
private static final IRIFactory iriFactory = IRIFactory.iriImplementation();
public static boolean warningsForIRIs = false;
// -------- IRI
public static NodeValue iri(NodeValue nv, String baseIRI) {
if (isIRI(nv.asNode())) return nv;
Node n2 = iri(nv.asNode(), baseIRI);
return NodeValue.makeNode(n2);
}
public static Node iri(Node nv, String baseIRI) {
if (nv.isURI()) return nv;
if (nv.isBlank()) {
// Skolemization of blank nodes to IRIs : Don't ask, just don't ask.
String x = nv.getBlankNodeLabel();
return Node.createURI("_:" + x);
}
if (nv.isLiteral() && nv.getLiteralDatatype() == null && nv.getLiteralLanguage().equals("")) {
// Plain literal
IRI iri = null;
String iriStr = nv.getLiteralLexicalForm();
// Level of checking?
if (baseIRI != null) {
IRI base = iriFactory.create(baseIRI);
iri = base.create(iriStr);
} else iri = iriFactory.create(iriStr);
if (!iri.isAbsolute()) throw new ExprEvalException("Relative IRI string: " + iriStr);
if (warningsForIRIs && iri.hasViolation(false)) {
String msg = "unknown violation from IRI library";
Iterator<Violation> iter = iri.violations(false);
if (iter.hasNext()) {
Violation viol = iter.next();
msg = viol.getShortMessage();
}
Log.warn(NodeFunctions.class, "Bad IRI: " + msg + ": " + iri);
}
return Node.createURI(iri.toString());
}
throw new ExprEvalException("Can't make an IRI from " + nv);
}
public static NodeValue strDatatype(NodeValue v1, NodeValue v2) {
if (!v1.isString()) throw new ExprEvalException("Not a string (arg 1): " + v1);
if (!v2.isIRI()) throw new ExprEvalException("Not an IRI (arg 2): " + v2);
String lex = v1.asString();
Node dt = v2.asNode();
// Check?
Node n = Node.createLiteral(lex, null, Node.getType(dt.getURI()));
return NodeValue.makeNode(n);
}
public static NodeValue strLang(NodeValue v1, NodeValue v2) {
if (!v1.isString()) throw new ExprEvalException("Not a string (arg 1): " + v1);
if (!v2.isString()) throw new ExprEvalException("Not a string (arg 2): " + v2);
String lex = v1.asString();
String lang = v2.asString();
// Check?
Node n = Node.createLiteral(lex, lang, null);
return NodeValue.makeNode(n);
}
}
