Hoists some constructs from microbean-bean into this project. Refresh…

README.md

@@ -15,7 +15,7 @@ changes, regardless of project version and without notice.**
 
 # Requirements
 
-microBean™ Assign requires a Java runtime of version 23 or higher.
+microBean™ Assign requires a Java runtime of version 21 or higher.
 
 # Installation
 
@@ -27,7 +27,7 @@ dependency:
   <groupId>org.microbean</groupId>
   <artifactId>microbean-assign</artifactId>
   <!-- Always check https://search.maven.org/artifact/org.microbean/microbean-bean for up-to-date available versions. -->
-  <version>0.0.5</version>
+  <version>0.0.6</version>
 </dependency>
 ```
 

pom.xml

@@ -73,7 +73,7 @@
     <java.util.logging.config.file>${project.basedir}/src/test/java/logging.properties</java.util.logging.config.file>
 
     <!-- maven-compiler-plugin properties -->
-    <maven.compiler.release>23</maven.compiler.release>
+    <maven.compiler.release>21</maven.compiler.release>
     <maven.compiler.showDeprecation>true</maven.compiler.showDeprecation>
     <maven.compiler.showWarnings>true</maven.compiler.showWarnings>
 
@@ -125,7 +125,7 @@
       <dependency>
         <groupId>org.junit</groupId>
         <artifactId>junit-bom</artifactId>
-        <version>5.11.3</version>
+        <version>5.13.1</version>
         <type>pom</type>
         <scope>import</scope>
       </dependency>
@@ -135,13 +135,19 @@
       <dependency>
         <groupId>org.microbean</groupId>
         <artifactId>microbean-attributes</artifactId>
-        <version>0.0.2</version>
+        <version>0.0.3</version>
+      </dependency>
+
+      <dependency>
+        <groupId>org.microbean</groupId>
+        <artifactId>microbean-constant</artifactId>
+        <version>0.0.7</version>
       </dependency>
 
       <dependency>
         <groupId>org.microbean</groupId>
         <artifactId>microbean-construct</artifactId>
-        <version>0.0.10</version>
+        <version>0.0.11</version>
       </dependency>
 
     </dependencies>
@@ -154,7 +160,13 @@
       <artifactId>microbean-attributes</artifactId>
       <scope>compile</scope>
     </dependency>
-
+
+    <dependency>
+      <groupId>org.microbean</groupId>
+      <artifactId>microbean-constant</artifactId>
+      <scope>compile</scope>
+    </dependency>
+
     <dependency>
       <groupId>org.microbean</groupId>
       <artifactId>microbean-construct</artifactId>
@@ -308,7 +320,7 @@
         </plugin>
         <plugin>
           <artifactId>maven-clean-plugin</artifactId>
-          <version>3.4.1</version>
+          <version>3.5.0</version>
           <configuration>
             <filesets>
               <fileset>
@@ -423,14 +435,7 @@
         </plugin>
         <plugin>
           <artifactId>maven-surefire-plugin</artifactId>
-          <version>3.5.2</version>
-          <dependencies>
-            <dependency>
-              <groupId>org.apache.maven.surefire</groupId>
-              <artifactId>surefire-junit-platform</artifactId>
-              <version>3.5.2</version>
-            </dependency>
-          </dependencies>
+          <version>3.5.3</version>
         </plugin>
         <plugin>
           <artifactId>maven-toolchains-plugin</artifactId>
@@ -439,7 +444,7 @@
         <plugin>
           <groupId>com.github.spotbugs</groupId>
           <artifactId>spotbugs-maven-plugin</artifactId>
-          <version>4.9.1.0</version>
+          <version>4.9.3.0</version>
         </plugin>
         <plugin>
           <groupId>org.codehaus.mojo</groupId>
@@ -449,7 +454,7 @@
         <plugin>
           <groupId>io.smallrye</groupId>
           <artifactId>jandex-maven-plugin</artifactId>
-          <version>3.2.7</version>
+          <version>3.3.1</version>
         </plugin>
         <plugin>
           <groupId>org.sonatype.plugins</groupId>

src/main/java/module-info.java

@@ -23,6 +23,7 @@
 
   requires transitive java.compiler;
   requires transitive org.microbean.attributes;
+  requires org.microbean.constant;
   requires transitive org.microbean.construct;
 
 }

src/main/java/org/microbean/assign/Aggregate.java

@@ -0,0 +1,93 @@
+/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
+ *
+ * Copyright © 2025 microBean™.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package org.microbean.assign;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.SequencedSet;
+
+import java.util.function.Function;
+
+import static java.util.Collections.unmodifiableSequencedSet;
+
+import static java.util.LinkedHashSet.newLinkedHashSet;
+
+/**
+ * An object with {@linkplain AttributedElement dependencies}.
+ *
+ * <p>By default, {@link Aggregate}s have {@linkplain #EMPTY_DEPENDENCIES no dependencies}.</p>
+ *
+ * @author <a href="https://about.me/lairdnelson/" target="_top">Laird Nelson</a>
+ *
+ * @see #dependencies()
+ */
+public interface Aggregate {
+
+
+  /*
+   * Static fields.
+   */
+
+
+  /**
+   * An immutable, empty {@link SequencedSet} of {@link Assignment}s.
+   */
+  public static final SequencedSet<Assignment<?>> EMPTY_ASSIGNMENTS = unmodifiableSequencedSet(newLinkedHashSet(0));
+
+  /**
+   * An immutable, empty {@link SequencedSet} of {@link AttributedElement}s.
+   */
+  public static final SequencedSet<AttributedElement> EMPTY_DEPENDENCIES = unmodifiableSequencedSet(newLinkedHashSet(0));
+
+
+  /*
+   * Default instance methods.
+   */
+
+
+  /**
+   * Returns an immutable {@link SequencedSet} of {@link AttributedElement} instances.
+   *
+   * @return an immutable {@link SequencedSet} of {@link AttributedElement} instances; never {@code null}
+   *
+   * @see AttributedElement
+   */
+  public default SequencedSet<AttributedElement> dependencies() {
+    return EMPTY_DEPENDENCIES;
+  }
+
+  /**
+   * A convenience method that assigns a contextual reference to each of this {@link Aggregate}'s {@link
+   * AttributedElement} instances and returns the resulting {@link SequencedSet} of {@link Assignment}s.
+   *
+   * <p>Typically there is no need to override this method.</p>
+   *
+   * @param r a {@link Function} that retrieves a contextual reference suitable for an {@link AttributedType}; if {@link
+   * #dependencies()} returns a non-empty {@link SequencedSet} then this argument must not be {@code null}
+   *
+   * @return an immutable {@link SequencedSet} of {@link Assignment} instances; never {@code null}
+   *
+   * @exception NullPointerException if {@code r} is {@code null}
+   */
+  public default SequencedSet<? extends Assignment<?>> assign(final Function<? super AttributedType, ?> r) {
+    final Collection<? extends AttributedElement> ds = this.dependencies();
+    if (ds == null || ds.isEmpty()) {
+      return EMPTY_ASSIGNMENTS;
+    }
+    final SequencedSet<Assignment<?>> assignments = newLinkedHashSet(ds.size());
+    ds.forEach(d -> assignments.add(new Assignment<>(d, r.apply(d.attributedType()))));
+    return Collections.unmodifiableSequencedSet(assignments);
+  }
+
+}

src/main/java/org/microbean/assign/Assignment.java

@@ -0,0 +1,45 @@
+/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
+ *
+ * Copyright © 2025 microBean™.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package org.microbean.assign;
+
+import java.util.Objects;
+
+/**
+ * An assignment of a value to an {@link AttributedElement}.
+ *
+ * @param <R> the value type
+ *
+ * @param assignee the {@link AttributedElement}; must not be {@code null}
+ *
+ * @param value the value; may be {@code null}
+ *
+ * @author <a href="https://about.me/lairdnelson" target="_top">Laird Nelson</a>
+ */
+// You're going to be tempted to replace the value component with a Supplier component. Don't do it. An assignment is a
+// value that belongs to, e.g., a field, so even if the value "came from" none/dependent/prototype scope, it was already
+// sourced and "belongs to" the field.
+public final record Assignment<R>(AttributedElement assignee, R value) {
+
+  /**
+   * Creates a new {@link Assignment}.
+   *
+   * @param assignee the {@link AttributedElement}; must not be {@code null}
+   *
+   * @param value the contextual reference; may be {@code null}
+   */
+  public Assignment {
+    Objects.requireNonNull(assignee, "assignee");
+  }
+
+}

src/main/java/org/microbean/assign/AttributedElement.java

@@ -0,0 +1,102 @@
+/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
+ *
+ * Copyright © 2025 microBean™.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package org.microbean.assign;
+
+import java.lang.constant.ClassDesc;
+import java.lang.constant.Constable;
+import java.lang.constant.ConstantDesc;
+import java.lang.constant.DynamicConstantDesc;
+import java.lang.constant.MethodHandleDesc;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+import javax.lang.model.element.Element;
+
+import javax.lang.model.type.TypeMirror;
+
+import org.microbean.attributes.Attributed;
+import org.microbean.attributes.Attributes;
+
+import org.microbean.constant.Constables;
+
+import static java.lang.constant.ConstantDescs.BSM_INVOKE;
+import static java.lang.constant.ConstantDescs.CD_List;
+
+/**
+ * A pairing of an {@link Element} with a {@link List} of {@link Attributes}s.
+ *
+ * @param element an {@link Element}
+ *
+ * @param attributes a {@link List} of {@link Attributes}s
+ *
+ * @author <a href="https://about.me/lairdnelson/" target="_top">Laird Nelson</a>
+ */
+public final record AttributedElement(Element element, List<Attributes> attributes) implements Attributed, Constable {
+
+  /**
+   * Creates a new {@link AttributedElement}.
+   *
+   * @param element a {@link Element}; must not be {@code null}
+   *
+   * @param attributes a {@link List} of {@link Attributes}; must not be {@code null}
+   *
+   * @exception NullPointerException if either argument is {@code null}
+   */
+  public AttributedElement {
+    Objects.requireNonNull(element, "element");
+    attributes = List.copyOf(attributes);
+  }
+
+  /**
+   * Returns this {@link AttributedElement}'s {@linkplain Element#asType() type}.
+   *
+   * @return this {@link AttributedElement}'s {@linkplain Element#asType() type}; never {@code null}
+   */
+  public final TypeMirror type() {
+    return this.element().asType();
+  }
+
+  /**
+   * Returns this {@link AttributedElement}'s {@link AttributedType}.
+   *
+   * @return this {@link AttributedElement}'s {@link AttributedType}; never {@code null}
+   *
+   * @see AttributedType
+   */
+  public final AttributedType attributedType() {
+    return new AttributedType(this.type(), this.attributes());
+  }
+
+  /**
+   * Returns an {@link Optional} containing a {@link ConstantDesc} describing this {@link AttributedType}, or an
+   * {@linkplain Optional#isEmpty() empty <code>Optional</code>} if it could not be described.
+   *
+   * @return an {@link Optional} containing a {@link ConstantDesc} describing this {@link AttributedType}, or an
+   * {@linkplain Optional#isEmpty() empty <code>Optional</code>} if it could not be describe; never {@code null}
+   */
+  @Override // Constable
+  public Optional<? extends ConstantDesc> describeConstable() {
+    return this.element() instanceof Constable e ? e.describeConstable() : Optional.<ConstantDesc>empty()
+      .flatMap(elementDesc -> Constables.describeConstable(this.attributes())
+               .map(attributesDesc -> DynamicConstantDesc.of(BSM_INVOKE,
+                                                             MethodHandleDesc.ofConstructor(ClassDesc.of(this.getClass().getName()),
+                                                                                            ClassDesc.of("javax.lang.model.element.Element"),
+                                                                                            CD_List),
+                                                             elementDesc,
+                                                             attributesDesc)));
+  }
+
+}