[feature] Implement the fn:collation-key function.

Author: chris-evolvedbinary

exist-core/src/main/java/org/exist/xquery/functions/fn/FnModule.java

@@ -52,6 +52,7 @@ public class FnModule extends AbstractInternalModule {
         new FunctionDef(FunCeiling.signature, FunCeiling.class),
         new FunctionDef(FunCodepointEqual.signature, FunCodepointEqual.class),
         new FunctionDef(FunCodepointsToString.signature, FunCodepointsToString.class),
+        new FunctionDef(FunCollationKey.FS_COLLATION_KEY_SIGNATURES[0], FunCollationKey.class),
         new FunctionDef(FunCompare.signatures[0], FunCompare.class),
         new FunctionDef(FunCompare.signatures[1], FunCompare.class),
         new FunctionDef(FunConcat.signature, FunConcat.class),

exist-core/src/main/java/org/exist/xquery/functions/fn/FunCollationKey.java

@@ -0,0 +1,68 @@
+/*
+ * eXist-db Open Source Native XML Database
+ * Copyright (C) 2001 The eXist-db Authors
+ *
+ * [email protected]
+ * http://www.exist-db.org
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package org.exist.xquery.functions.fn;
+
+import org.apache.commons.codec.binary.Base64;
+import org.exist.dom.QName;
+import org.exist.util.Collations;
+import org.exist.xquery.*;
+import org.exist.xquery.value.*;
+
+import com.ibm.icu.text.Collator;
+
+public class FunCollationKey extends BasicFunction {
+
+    private static final QName FN_NAME = new QName("collation-key", Function.BUILTIN_FUNCTION_NS, FnModule.PREFIX);
+    private static final String FN_DESCRIPTION =
+            "Given a $value-string value and a $collection-string " +
+                    "collation, generates an internal value called a collation key, with the " +
+                    "property that the matching and ordering of collation " +
+                    "keys reflects the matching and ordering of strings " +
+                    "under the specified collation.";
+    private static final FunctionReturnSequenceType FN_RETURN = new FunctionReturnSequenceType(
+            Type.BASE64_BINARY, Cardinality.ZERO_OR_ONE, "the collation key"
+    );
+
+    public static final FunctionSignature[] FS_COLLATION_KEY_SIGNATURES = {
+            new FunctionSignature(FunCollationKey.FN_NAME, FunCollationKey.FN_DESCRIPTION,
+                    new SequenceType[] {
+                            new FunctionParameterSequenceType("value-string", Type.STRING,
+                                    Cardinality.ZERO_OR_ONE, "The value string"),
+                            new FunctionParameterSequenceType("collection-string", Type.STRING,
+                                    Cardinality.ZERO_OR_ONE, "The collation string")
+                    }, FN_RETURN)
+
+    };
+
+    public FunCollationKey(final XQueryContext context, final FunctionSignature signature) {
+        super(context, signature);
+    }
+
+    public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
+        final BinaryValue result;
+        final String source = (args.length >= 1) ? args[0].toString() : "";
+        final Collator collator = (args.length >= 2) ? Collations.getCollationFromURI(args[1].toString()) : context.getDefaultCollator();
+        result = new BinaryValueFromBinaryString(new Base64BinaryValueType(), Base64.encodeBase64String(collator.getCollationKey(source).toByteArray()));
+        return result;
+    }
+}

exist-core/src/test/xquery/xquery3/fnCodepointEqual.xqm

@@ -0,0 +1,56 @@
+(:
+ : eXist-db Open Source Native XML Database
+ : Copyright (C) 2001 The eXist-db Authors
+ :
+ : [email protected]
+ : http://www.exist-db.org
+ :
+ : This library is free software; you can redistribute it and/or
+ : modify it under the terms of the GNU Lesser General Public
+ : License as published by the Free Software Foundation; either
+ : version 2.1 of the License, or (at your option) any later version.
+ :
+ : This library is distributed in the hope that it will be useful,
+ : but WITHOUT ANY WARRANTY; without even the implied warranty of
+ : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ : Lesser General Public License for more details.
+ :
+ : You should have received a copy of the GNU Lesser General Public
+ : License along with this library; if not, write to the Free Software
+ : Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ :)
+xquery version "3.1";
+
+module namespace fnp="http://exist-db.org/xquery/test/function_codepoint_equal";
+
+declare namespace test="http://exist-db.org/xquery/xqsuite";
+
+declare
+    %test:assertEmpty
+function fnp:empty-sequences() {
+    fn:codepoint-equal((), ())
+};
+
+declare
+    %test:assertEmpty
+function fnp:empty-string-and-empty-sequence() {
+    fn:codepoint-equal("", ())
+};
+
+declare
+    %test:assertTrue
+function fnp:empty-strings() {
+    fn:codepoint-equal("", "")
+};
+
+declare
+    %test:assertTrue
+function fnp:equal() {
+    fn:codepoint-equal("abcd", "abcd")
+};
+
+declare
+    %test:assertFalse
+function fnp:not-equal() {
+    fn:codepoint-equal("abcd", "abcd ")
+};

exist-core/src/test/xquery/xquery3/fnCollationKey.xqm

@@ -0,0 +1,50 @@
+(:
+ : eXist-db Open Source Native XML Database
+ : Copyright (C) 2001 The eXist-db Authors
+ :
+ : [email protected]
+ : http://www.exist-db.org
+ :
+ : This library is free software; you can redistribute it and/or
+ : modify it under the terms of the GNU Lesser General Public
+ : License as published by the Free Software Foundation; either
+ : version 2.1 of the License, or (at your option) any later version.
+ :
+ : This library is distributed in the hope that it will be useful,
+ : but WITHOUT ANY WARRANTY; without even the implied warranty of
+ : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ : Lesser General Public License for more details.
+ :
+ : You should have received a copy of the GNU Lesser General Public
+ : License along with this library; if not, write to the Free Software
+ : Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ :)
+xquery version "3.1";
+
+module namespace fnp="http://exist-db.org/xquery/test/function_collation_key";
+
+declare namespace test="http://exist-db.org/xquery/xqsuite";
+
+declare
+    %test:assertTrue
+function fnp:equal() {
+    let $first := fn:collation-key("a", "http://www.w3.org/2013/collation/UCA?strength=primary")
+    let $second := fn:collation-key("a", "http://www.w3.org/2013/collation/UCA?strength=primary")
+    return $first = $second
+};
+
+declare
+    %test:assertTrue
+function fnp:equal-ignore-case() {
+    let $first := fn:collation-key("a", "http://www.w3.org/2013/collation/UCA?strength=primary")
+    let $second := fn:collation-key("A", "http://www.w3.org/2013/collation/UCA?strength=primary")
+    return $first = $second
+};
+
+declare
+    %test:assertTrue
+function fnp:not-equal() {
+    let $first := fn:collation-key("a", "http://www.w3.org/2013/collation/UCA?strength=primary")
+    let $second := fn:collation-key("b", "http://www.w3.org/2013/collation/UCA?strength=primary")
+    return $first != $second
+};