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david-waltermiredavid-waltermire
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Added support for the Metapath function map:for-each. Resolves metaschema-framework#301 
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5 files changed

+182
-2
lines changed

5 files changed

+182
-2
lines changed

‎core/src/main/java/gov/nist/secauto/metaschema/core/metapath/cst/AnonymousFunctionCall.java

Lines changed: 4 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -146,7 +146,10 @@ protected ISequence<?> executeInternal(
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subContext.bindVariableValue(param.getName(), ObjectUtils.notNull(sequence));
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}
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return body.accept(subContext, ISequence.of(focus));
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// the focus is not present according to
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// https://www.w3.org/TR/xpath-31/#id-eval-function-call
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// paragraph 5.b.ii
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return body.accept(subContext, ISequence.empty());
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}
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}
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}

‎core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/IFunction.java

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@@ -70,6 +70,16 @@ enum FunctionProperty {
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UNBOUNDED_ARITY;
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}
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/**
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* Get the type information for this item.
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*
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* @return the type information
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*/
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@NonNull
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static IItemType type() {
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return IItemType.function();
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}
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@Override
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default IItemType getType() {
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// TODO: implement this based on the signature

‎core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/DefaultFunctionLibrary.java

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -268,7 +268,8 @@ public DefaultFunctionLibrary() { // NOPMD - intentional
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registerFunction(MapEntry.SIGNATURE);
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// https://www.w3.org/TR/xpath-functions-31/#func-map-remove
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registerFunction(MapRemove.SIGNATURE);
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// P3: https://www.w3.org/TR/xpath-functions-31/#func-map-for-each
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// https://www.w3.org/TR/xpath-functions-31/#func-map-for-each
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registerFunction(MapForEach.SIGNATURE);
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// metapath casting functions
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DataTypeService.instance().getDataTypes().stream()

‎core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/MapForEach.java

Lines changed: 115 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,115 @@
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/*
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* SPDX-FileCopyrightText: none
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* SPDX-License-Identifier: CC0-1.0
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*/
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package gov.nist.secauto.metaschema.core.metapath.function.library;
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import gov.nist.secauto.metaschema.core.metapath.DynamicContext;
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import gov.nist.secauto.metaschema.core.metapath.MetapathConstants;
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import gov.nist.secauto.metaschema.core.metapath.function.FunctionUtils;
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import gov.nist.secauto.metaschema.core.metapath.function.IArgument;
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import gov.nist.secauto.metaschema.core.metapath.function.IFunction;
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import gov.nist.secauto.metaschema.core.metapath.item.IItem;
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import gov.nist.secauto.metaschema.core.metapath.item.ISequence;
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import gov.nist.secauto.metaschema.core.metapath.item.atomic.IAnyAtomicItem;
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import gov.nist.secauto.metaschema.core.metapath.item.function.IMapItem;
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import gov.nist.secauto.metaschema.core.util.ObjectUtils;
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import java.util.List;
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import java.util.function.BiFunction;
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import edu.umd.cs.findbugs.annotations.NonNull;
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/**
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* Implements the XPath 3.1 <a href=
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* "https://www.w3.org/TR/xpath-functions-31/#func-map-contains">map:contains</a>
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* function.
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*/
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public final class MapForEach {
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private static final String NAME = "for-each";
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@NonNull
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static final IFunction SIGNATURE = IFunction.builder()
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.name(NAME)
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.namespace(MetapathConstants.NS_METAPATH_FUNCTIONS_MAP)
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.deterministic()
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.contextIndependent()
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.focusIndependent()
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.argument(IArgument.builder()
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.name("map")
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.type(IMapItem.type())
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.one()
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.build())
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.argument(IArgument.builder()
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.name("action")
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.type(IFunction.type())
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.one()
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.build())
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.returnType(IItem.type())
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.returnOne()
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.functionHandler(MapForEach::execute)
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.build();
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private MapForEach() {
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// disable construction
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}
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@SuppressWarnings("unused")
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@NonNull
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private static ISequence<?> execute(@NonNull IFunction function,
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@NonNull List<ISequence<?>> arguments,
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@NonNull DynamicContext dynamicContext,
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IItem focus) {
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IMapItem<?> map = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(0).getFirstItem(true)));
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IFunction action = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(1).getFirstItem(true)));
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BiFunction<IAnyAtomicItem, ISequence<?>, ISequence<?>> lambda = adaptFunction(action, dynamicContext);
67+
return forEach(map, lambda);
68+
}
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/**
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* Adapts the provided function call to a lambda expression for use with
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* {@link #forEach(IMapItem, BiFunction)}.
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*
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* @param function
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* the function to adapt
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* @param dynamicContext
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* the dynamic context for use in evaluating the function
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* @return
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*/
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@NonNull
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private static BiFunction<IAnyAtomicItem, ISequence<?>, ISequence<?>> adaptFunction(
82+
@NonNull IFunction function,
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@NonNull DynamicContext dynamicContext) {
84+
return (key, value) -> {
85+
List<ISequence<?>> arguments = ObjectUtils.notNull(List.of(
86+
ISequence.of(key),
87+
value.toSequence()));
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return function.execute(arguments, dynamicContext, ISequence.empty());
90+
};
91+
}
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/**
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* An implementation of XPath 3.1 <a href=
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* "https://www.w3.org/TR/xpath-functions-31/#func-map-for-each">map:for-each</a>.
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*
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* @param map
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* the map of Metapath items that is the target of retrieval
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* @param action
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* the action to perform on each entry in the map
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* @return a stream resulting from concatenating the resulting streams provided
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* by the action result
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*/
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@NonNull
105+
public static ISequence<?> forEach(
106+
@NonNull IMapItem<?> map,
107+
@NonNull BiFunction<IAnyAtomicItem, ISequence<?>, ISequence<?>> action) {
108+
return ISequence.of(ObjectUtils.notNull(map.entrySet().stream()
109+
.flatMap(entry -> {
110+
IAnyAtomicItem key = entry.getKey().getKey();
111+
ISequence<?> values = entry.getValue().contentsAsSequence();
112+
return action.apply(key, values).stream();
113+
})));
114+
}
115+
}

‎core/src/test/java/gov/nist/secauto/metaschema/core/metapath/function/library/MapForEachTest.java

Lines changed: 51 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,51 @@
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/*
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* SPDX-FileCopyrightText: none
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* SPDX-License-Identifier: CC0-1.0
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*/
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package gov.nist.secauto.metaschema.core.metapath.function.library;
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import static gov.nist.secauto.metaschema.core.metapath.TestUtils.entry;
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import static gov.nist.secauto.metaschema.core.metapath.TestUtils.integer;
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import static gov.nist.secauto.metaschema.core.metapath.TestUtils.map;
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import static gov.nist.secauto.metaschema.core.metapath.TestUtils.sequence;
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import static gov.nist.secauto.metaschema.core.metapath.TestUtils.string;
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import static org.assertj.core.api.Assertions.assertThat;
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import gov.nist.secauto.metaschema.core.metapath.ExpressionTestBase;
16+
import gov.nist.secauto.metaschema.core.metapath.IMetapathExpression;
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import gov.nist.secauto.metaschema.core.metapath.item.IItem;
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import gov.nist.secauto.metaschema.core.metapath.item.ISequence;
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import org.junit.jupiter.params.ParameterizedTest;
21+
import org.junit.jupiter.params.provider.Arguments;
22+
import org.junit.jupiter.params.provider.MethodSource;
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import java.util.stream.Stream;
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import edu.umd.cs.findbugs.annotations.NonNull;
27+
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class MapForEachTest
29+
extends ExpressionTestBase {
30+
31+
private static Stream<Arguments> provideValues() { // NOPMD - false positive
32+
return Stream.of(
33+
Arguments.of(
34+
sequence(integer(1), integer(2)),
35+
"map:for-each(map{1:'yes', 2:'no'}, function($k, $v){$k})"),
36+
Arguments.of(
37+
sequence(string("yes"), string("no")),
38+
"distinct-values(map:for-each(map{1:'yes', 2:'no'}, function($k, $v){$v}))"),
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Arguments.of(
40+
sequence(map(entry(string("a"), integer(2)), entry(string("b"), integer(3)))),
41+
"map:merge(map:for-each(map{'a':1, 'b':2}, function($k, $v){map:entry($k, $v+1)}))"));
42+
}
43+
44+
@ParameterizedTest
45+
@MethodSource("provideValues")
46+
void testExpression(@NonNull ISequence<IItem> expected, @NonNull String metapath) {
47+
48+
ISequence<IItem> result = IMetapathExpression.compile(metapath).evaluate(null, newDynamicContext());
49+
assertThat(result).containsAll(expected);
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}
51+
}

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