[
https://issues.apache.org/jira/browse/GROOVY-11998?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18078641#comment-18078641
]
ASF GitHub Bot commented on GROOVY-11998:
-----------------------------------------
Copilot commented on code in PR #2518:
URL: https://github.com/apache/groovy/pull/2518#discussion_r3194619370
##########
src/main/java/org/codehaus/groovy/transform/stc/StaticTypeCheckingVisitor.java:
##########
@@ -4800,7 +4807,89 @@ public void visitCastExpression(final CastExpression
expression) {
}
}
+ /**
+ * Validates JLS §4.9 well-formedness of an intersection cast target,
+ * and for lambda / method-reference / closure operands picks the
+ * SAM-bearing component as the primary functional target so that
+ * parameter inference (and downstream lambda factory generation)
+ * can proceed. Additional components are stored as
+ * {@link StaticTypesMarker#LAMBDA_MARKERS} on both the cast and
+ * source for use by the bytecode writers.
+ */
+ private void validateAndApplyIntersectionCast(final
IntersectionTypeClassNode target,
+ final CastExpression
expression,
+ final Expression source) {
+ ClassNode[] components = target.getComponents();
+ int classCount = 0;
+ boolean classNotFirst = false;
+ for (int i = 0, n = components.length; i < n; i += 1) {
+ ClassNode c = components[i];
+ if (isPrimitiveType(c)) {
+ addStaticTypeError("Intersection type components must be
reference types: " + prettyPrintType(c), expression);
+ }
+ if (!c.isInterface()) {
+ classCount += 1;
+ if (i != 0) classNotFirst = true;
+ if (Modifier.isFinal(c.getModifiers())) {
+ addStaticTypeError("Intersection type may not include the
final class " + prettyPrintType(c), expression);
+ }
+ }
+ }
+ if (classCount > 1) {
+ addStaticTypeError("Intersection type may include at most one
class component: " + prettyPrintType(target), expression);
+ }
+ if (classNotFirst) {
+ addStaticTypeError("Class component of intersection type must come
first: " + prettyPrintType(target), expression);
+ }
+
+ boolean isFunctionalSource = source instanceof ClosureExpression
Review Comment:
`validateAndApplyIntersectionCast` intends to handle lambda sources (it
later checks `source instanceof LambdaExpression`), but `isFunctionalSource`
currently only covers `ClosureExpression` and `MethodReferenceExpression`. As a
result, intersection casts on `LambdaExpression` will skip primary/marker
selection and metadata setup, breaking serializable/marker handling for
lambdas. Include `LambdaExpression` in the functional-source check (and keep
the subsequent lambda-specific serializable handling reachable).
##########
src/main/java/org/codehaus/groovy/runtime/IntersectionCastSupport.java:
##########
@@ -0,0 +1,103 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.codehaus.groovy.runtime;
+
+import groovy.lang.Closure;
+import groovy.util.ProxyGenerator;
+import org.codehaus.groovy.runtime.typehandling.GroovyCastException;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Runtime support for intersection-type cast and {@code as} coercion
+ * (GROOVY-11998). Compiler-generated bytecode for {@code (A & B) value} and
+ * {@code value as (A & B)} routes through these helpers when the target is
+ * an intersection type and the source is not a native lambda or method
+ * reference (those cases are handled at compile time via
+ * {@code LambdaMetafactory.altMetafactory} markers).
+ *
+ * @since 5.0.0
Review Comment:
The Javadoc `@since` tag says `5.0.0`, but this feature is introduced as
part of Groovy 6.0 (the specs and tests in this PR also say “Since Groovy
6.0”). Please update the `@since` version to match the actual release version
that will contain this API.
##########
src/main/java/org/codehaus/groovy/ast/IntersectionTypeClassNode.java:
##########
@@ -0,0 +1,103 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.codehaus.groovy.ast;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.StringJoiner;
+
+import static org.objectweb.asm.Opcodes.ACC_FINAL;
+import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
+
+/**
+ * Represents a user-written intersection type used as the target of a cast
+ * expression or {@code as} coercion, e.g.
+ * <pre>
+ * (Runnable & Serializable) () -> ...
+ * value as (A & B)
+ * </pre>
+ *
+ * <p>Distinct from the implicit lowest-upper-bound nodes that
+ * {@link org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor}
+ * synthesises during inference: an instance of this class records the ordered
+ * list of components exactly as written by the user. That ordering is needed
+ * for cast-conversion checks, error messages and (in later phases) bytecode
+ * generation via {@code LambdaMetafactory.altMetafactory} markers.
+ *
+ * <p>Lifecycle: at parse time the components have not yet been resolved to
+ * bound {@link ClassNode}s, so the constructor places all components in the
+ * inherited {@link #getInterfaces() interfaces} array with {@code Object} as
+ * the placeholder superclass. After {@code ResolveVisitor} resolves each
+ * component it should call {@link #reclassifyComponents()} so that the
+ * interfaces array contains only interface components and the superclass is
+ * the (at most one) class component.
+ *
+ * @since 5.0.0
Review Comment:
The Javadoc `@since` tag is `5.0.0`, but this class is being introduced for
Groovy 6.0 intersection-type casts. Please align `@since` with the actual
Groovy version this API ships in.
##########
src/spec/doc/core-semantics.adoc:
##########
@@ -759,6 +759,65 @@ The type of the exception depends on the call itself:
* `MissingMethodException` if the arguments of the call do not match those
from the interface/class
* `UnsupportedOperationException` if the arguments of the call match one of
the overloaded methods of the interface/class
+[[intersection-cast]]
+=== Intersection-type cast and coercion
+
+Since Groovy 6.0, the cast and `as` operators accept _intersection types_ — a
+class component (at most one) and any number of interface components joined by
+`&`, mirroring Java's
+https://docs.oracle.com/javase/specs/jls/se21/html/jls-15.html#jls-15.16[JLS
§15.16]
+intersection cast. The most common use is to opt a lambda or method reference
+into `Serializable`:
+
+[source,groovy]
+----
+include::../test/CoercionTest.groovy[tags=intersection_cast_lambda,indent=0]
+----
+
+For statically compiled lambdas and method references, the additional
+interfaces are threaded through `LambdaMetafactory.altMetafactory` via
+`FLAG_MARKERS` / `FLAG_SERIALIZABLE` — there is no runtime proxy and the
+result implements every component natively, so it can be serialised and
+restored:
+
+[source,groovy]
+----
+include::../test/CoercionTest.groovy[tags=intersection_cast_serializable_roundtrip,indent=0]
+----
+
+The same syntax works in the `as` form, with parentheses around the
intersection:
+
+[source,groovy]
+----
+include::../test/CoercionTest.groovy[tags=intersection_as_coercion_marker,indent=0]
+----
+
+For closure literals and maps, `as` builds a
+{@link groovy.util.ProxyGenerator} aggregate that implements every interface
Review Comment:
`{@link ...}` is Javadoc syntax and doesn’t render as a link in AsciiDoc.
Use the docs’ link conventions instead (e.g., backticks around the type name,
or an AsciiDoc `link:`/`xref:`), so the reference to
`groovy.util.ProxyGenerator` renders correctly.
##########
src/test/groovy/org/apache/groovy/parser/antlr4/IntersectionCastParserTest.groovy:
##########
@@ -0,0 +1,173 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.apache.groovy.parser.antlr4
+
+import org.codehaus.groovy.ast.ClassNode
+import org.codehaus.groovy.ast.IntersectionTypeClassNode
+import org.codehaus.groovy.ast.ModuleNode
+import org.codehaus.groovy.ast.expr.CastExpression
+import org.codehaus.groovy.ast.expr.ClassExpression
+import org.codehaus.groovy.ast.expr.DeclarationExpression
+import org.codehaus.groovy.ast.expr.Expression
+import org.codehaus.groovy.ast.expr.BinaryExpression
+import org.codehaus.groovy.ast.stmt.BlockStatement
+import org.codehaus.groovy.ast.stmt.ExpressionStatement
+import org.codehaus.groovy.control.CompilerConfiguration
+import org.codehaus.groovy.control.ParserPlugin
+import org.codehaus.groovy.control.ParserPluginFactory
+import org.junit.jupiter.api.Test
+
+import static org.junit.jupiter.api.Assertions.assertNotNull
+import static org.junit.jupiter.api.Assertions.assertTrue
+import static org.junit.jupiter.api.Assertions.assertEquals
+import static org.junit.jupiter.api.Assertions.assertThrows
Review Comment:
Unused import: `assertThrows` is imported but not used in this test class.
##########
src/main/java/org/codehaus/groovy/classgen/asm/sc/AbstractFunctionalInterfaceWriter.java:
##########
@@ -78,11 +78,32 @@ default void writeFunctionalInterfaceIndy(final
MethodVisitor methodVisitor,
final String
samMethodDescriptor, final int implMethodKind,
final ClassNode implClassNode,
final MethodNode implMethodNode,
final Parameter[]
implMethodParameters, final boolean serializable) {
+ // GROOVY-11998: delegate to marker-aware overload with no extra
interfaces
+ writeFunctionalInterfaceIndy(methodVisitor, samMethodName,
invokedTypeDescriptor,
+ samMethodDescriptor, implMethodKind, implClassNode,
implMethodNode,
+ implMethodParameters, serializable, ClassNode.EMPTY_ARRAY);
+ }
+
+ /**
+ * Marker-aware variant for intersection-cast targets such as
+ * {@code (Runnable & Cloneable) () -> ...}. Markers are threaded through
+ * {@code LambdaMetafactory.altMetafactory} via {@code FLAG_MARKERS} so the
+ * generated lambda implements every component interface at runtime.
+ *
+ * @since 5.0.0
+ */
+ default void writeFunctionalInterfaceIndy(final MethodVisitor
methodVisitor,
+ final String samMethodName,
final String invokedTypeDescriptor,
+ final String
samMethodDescriptor, final int implMethodKind,
+ final ClassNode implClassNode,
final MethodNode implMethodNode,
+ final Parameter[]
implMethodParameters, final boolean serializable,
+ final ClassNode[] markers) {
+ boolean useAlt = serializable || (markers != null && markers.length >
0);
Review Comment:
The new marker-aware overload is documented as `@since 5.0.0`, but it
appears to be introduced by this Groovy 6.0 intersection-cast work. Please
update `@since` to the correct version to avoid misleading API documentation.
##########
src/test/groovy/org/apache/groovy/parser/antlr4/IntersectionCastParserTest.groovy:
##########
@@ -0,0 +1,173 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.apache.groovy.parser.antlr4
+
+import org.codehaus.groovy.ast.ClassNode
+import org.codehaus.groovy.ast.IntersectionTypeClassNode
+import org.codehaus.groovy.ast.ModuleNode
+import org.codehaus.groovy.ast.expr.CastExpression
+import org.codehaus.groovy.ast.expr.ClassExpression
Review Comment:
Unused import: `org.codehaus.groovy.ast.expr.ClassExpression` isn’t
referenced in this test file. Removing unused imports helps keep the test
focused and avoids confusion when refactoring.
##########
src/test/groovy/groovy/transform/stc/IntersectionCastSTCTest.groovy:
##########
@@ -0,0 +1,243 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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 groovy.transform.stc
+
+import groovy.transform.TypeChecked
+import org.codehaus.groovy.ast.ClassNode
+import org.codehaus.groovy.ast.IntersectionTypeClassNode
+import org.codehaus.groovy.ast.expr.CastExpression
+import org.codehaus.groovy.ast.expr.LambdaExpression
+import org.codehaus.groovy.ast.tools.GenericsUtils
+import org.codehaus.groovy.control.CompilationUnit
+import org.codehaus.groovy.control.CompilerConfiguration
+import org.codehaus.groovy.control.MultipleCompilationErrorsException
+import org.codehaus.groovy.control.Phases
+import org.codehaus.groovy.control.SourceUnit
+import org.codehaus.groovy.control.customizers.ASTTransformationCustomizer
+import org.codehaus.groovy.control.customizers.ImportCustomizer
+import org.codehaus.groovy.control.messages.SyntaxErrorMessage
+import org.codehaus.groovy.transform.stc.StaticTypesMarker
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Test
+
+/**
+ * Tests for static type checking of intersection-cast targets (GROOVY-11998
PR2).
+ *
+ * These tests stop compilation at {@link Phases#SEMANTIC_ANALYSIS} so they
+ * exercise resolution and STC without relying on bytecode generation, which
+ * is delivered in subsequent phases.
Review Comment:
The class-level comment says compilation stops at
`Phases.SEMANTIC_ANALYSIS`, but `compileToSemantic` actually compiles to
`Phases.INSTRUCTION_SELECTION`. Either adjust the phase used (if the intent is
to stop at semantic analysis) or update the comment/method name to reflect what
the test is really doing.
> Better support of intersection types
> ------------------------------------
>
> Key: GROOVY-11998
> URL: https://issues.apache.org/jira/browse/GROOVY-11998
> Project: Groovy
> Issue Type: Improvement
> Reporter: Paul King
> Priority: Major
>
> E.g. to support
> {code:java}
> Runnable r = (Runnable & Serializable) () -> System.out.println("please
> serialize this message");
> {code}
> from here:
> https://www.baeldung.com/java-serialize-lambda
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
