feat: partial references

References marked as partial are not concretized during model generation. The
should be managed by the user manually using propagation rules instead.

4 files changed, 46 insertions, 11 deletions

diff --git a/subprojects/language/src/main/java/tools/refinery/language/Problem.xtext b/subprojects/language/src/main/java/tools/refinery/language/Problem.xtext
index ebb5bf71..10e994a0 100644
--- a/subprojects/language/src/main/java/tools/refinery/language/Problem.xtext
+++ b/subprojects/language/src/main/java/tools/refinery/language/Problem.xtext
@@ -45,7 +45,7 @@ AggregatorDeclaration:
         "extern" "aggregator" name=Identifier ".";
 
 enum ReferenceKind:
-        REFERENCE="refers" | CONTAINMENT="contains" | CONTAINER="container";
+        REFERENCE="refers" | CONTAINMENT="contains" | CONTAINER="container" | PARTIAL="partial";
 
 ReferenceDeclaration:
         (referenceType=[Relation|NonContainmentQualifiedName] |
diff --git a/subprojects/language/src/main/java/tools/refinery/language/utils/ProblemUtil.java b/subprojects/language/src/main/java/tools/refinery/language/utils/ProblemUtil.java
index 9daa8f61..e1820261 100644
--- a/subprojects/language/src/main/java/tools/refinery/language/utils/ProblemUtil.java
+++ b/subprojects/language/src/main/java/tools/refinery/language/utils/ProblemUtil.java
@@ -42,13 +42,11 @@ public final class ProblemUtil {
         }
 
         public static boolean isImplicit(EObject eObject) {
-                if (eObject instanceof Node node) {
-                        return isImplicitNode(node);
-                } else if (eObject instanceof Variable variable) {
-                        return isImplicitVariable(variable);
-                } else {
-                        return false;
-                }
+                return switch (eObject) {
+                        case Node node -> isImplicitNode(node);
+                        case Variable variable -> isImplicitVariable(variable);
+                        default -> false;
+                };
         }
 
         public static boolean isError(EObject eObject) {
@@ -119,7 +117,7 @@ public final class ProblemUtil {
                         return false;
                 }
                 return switch (kind) {
-                        case CONTAINMENT -> false;
+                        case CONTAINMENT, PARTIAL -> false;
                         case CONTAINER -> true;
                         case DEFAULT, REFERENCE -> {
                                 var opposite = referenceDeclaration.getOpposite();
diff --git a/subprojects/language/src/main/java/tools/refinery/language/validation/ProblemValidator.java b/subprojects/language/src/main/java/tools/refinery/language/validation/ProblemValidator.java
index 9f5fdeae..754572d1 100644
--- a/subprojects/language/src/main/java/tools/refinery/language/validation/ProblemValidator.java
+++ b/subprojects/language/src/main/java/tools/refinery/language/validation/ProblemValidator.java
@@ -318,6 +318,11 @@ public class ProblemValidator extends AbstractProblemValidator {
                                                 referenceDeclaration, ProblemPackage.Literals.REFERENCE_DECLARATION__OPPOSITE, 0,
                                                 INVALID_OPPOSITE_ISSUE);
                         }
+                } else if (kind == ReferenceKind.PARTIAL && opposite != null && opposite.getKind() != ReferenceKind.PARTIAL) {
+                        acceptError("Opposite '%s' of partial reference '%s' is not a partial reference."
+                                                        .formatted(opposite.getName(), referenceDeclaration.getName()),
+                                        referenceDeclaration, ProblemPackage.Literals.REFERENCE_DECLARATION__OPPOSITE, 0,
+                                        INVALID_OPPOSITE_ISSUE);
                 }
         }
 
diff --git a/subprojects/language/src/test/java/tools/refinery/language/tests/validation/OppositeValidationTest.java b/subprojects/language/src/test/java/tools/refinery/language/tests/validation/OppositeValidationTest.java
index 57602377..d73ef8e7 100644
--- a/subprojects/language/src/test/java/tools/refinery/language/tests/validation/OppositeValidationTest.java
+++ b/subprojects/language/src/test/java/tools/refinery/language/tests/validation/OppositeValidationTest.java
@@ -57,6 +57,18 @@ class OppositeValidationTest {
                         class Foo {
                                 Foo foo[] opposite foo
                         }
+                        """, """
+                        class Foo {
+                                partial Bar bar opposite foo
+                        }
+
+                        class Bar {
+                                partial Foo foo opposite bar
+                        }
+                        """, """
+                        class Foo {
+                                partial Foo foo[] opposite foo
+                        }
                         """})
         void validOppositeTest(String text) {
                 var problem = parseHelper.parse(text);
@@ -188,7 +200,7 @@ class OppositeValidationTest {
         }
 
         @ParameterizedTest
-        @ValueSource(strings = {"Foo foo", "container Foo foo"})
+        @ValueSource(strings = {"Foo foo", "container Foo foo", "partial Foo foo"})
         void containerInvalidOppositeTest(String reference) {
                 var problem = parseHelper.parse("""
                                 class Foo {
@@ -203,7 +215,27 @@ class OppositeValidationTest {
                 assertThat(issues, hasItem(allOf(
                                 hasProperty("severity", is(Diagnostic.ERROR)),
                                 hasProperty("issueCode", is(ProblemValidator.INVALID_OPPOSITE_ISSUE)),
-                                hasProperty("message", stringContainsInOrder("foo", "bar"))
+                                hasProperty("message", stringContainsInOrder("foo", "container", "bar"))
+                )));
+        }
+
+        @ParameterizedTest
+        @ValueSource(strings = {"Foo foo", "contains Foo foo", "container Foo foo"})
+        void partialWithConcreteOppositeTest(String reference) {
+                var problem = parseHelper.parse("""
+                                class Foo {
+                                        partial Bar bar opposite foo
+                                }
+
+                                class Bar {
+                                        %s opposite bar
+                                }
+                                """.formatted(reference));
+                var issues = problem.validate();
+                assertThat(issues, hasItem(allOf(
+                                hasProperty("severity", is(Diagnostic.ERROR)),
+                                hasProperty("issueCode", is(ProblemValidator.INVALID_OPPOSITE_ISSUE)),
+                                hasProperty("message", stringContainsInOrder("foo", "partial", "bar"))
                 )));
         }
 }