Support runtime checks of intersection types

CHANGELOG.md

@@ -945,6 +945,7 @@
 - [Use `numpy` & co. from Enso!][7678]
 - [Changed layout of local libraries directory, making it easier to reference
   projects next to each other][7634]
+- [Support runtime checks of intersection types][7769]
 - [Merge `Small_Integer` and `Big_Integer` types][7636]
 
 [3227]: https://github.com/enso-org/enso/pull/3227
@@ -1083,6 +1084,7 @@
 [7613]: https://github.com/enso-org/enso/pull/7613
 [7678]: https://github.com/enso-org/enso/pull/7678
 [7634]: https://github.com/enso-org/enso/pull/7634
+[7769]: https://github.com/enso-org/enso/pull/7769
 [7636]: https://github.com/enso-org/enso/pull/7636
 
 # Enso 2.0.0-alpha.18 (2021-10-12)

engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/type/Set.scala

@@ -650,108 +650,4 @@ object Set {
   object Intersection extends Info {
     override val name: String = "&"
   }
-
-  /** The typeset subtraction operator `\`.
-    *
-    * @param left        the left operand
-    * @param right       the right operand
-    * @param location    the source location that the node corresponds to
-    * @param passData    the pass metadata associated with this node
-    * @param diagnostics compiler diagnostics for this node
-    */
-  sealed case class Subtraction(
-    left: Expression,
-    right: Expression,
-    override val location: Option[IdentifiedLocation],
-    override val passData: MetadataStorage      = MetadataStorage(),
-    override val diagnostics: DiagnosticStorage = DiagnosticStorage()
-  ) extends Set
-      with IRKind.Primitive {
-    override protected var id: Identifier = randomId
-
-    /** Creates a copy of `this`.
-      *
-      * @param left        the left operand
-      * @param right       the right operand
-      * @param location    the source location that the node corresponds to
-      * @param passData    the pass metadata associated with this node
-      * @param diagnostics compiler diagnostics for this node
-      * @param id          the identifier for the new node
-      * @return a copy of `this`, updated with the specified values
-      */
-    def copy(
-      left: Expression                     = left,
-      right: Expression                    = right,
-      location: Option[IdentifiedLocation] = location,
-      passData: MetadataStorage            = passData,
-      diagnostics: DiagnosticStorage       = diagnostics,
-      id: Identifier                       = id
-    ): Subtraction = {
-      val res = Subtraction(left, right, location, passData, diagnostics)
-      res.id = id
-      res
-    }
-
-    /** @inheritdoc */
-    override def duplicate(
-      keepLocations: Boolean   = true,
-      keepMetadata: Boolean    = true,
-      keepDiagnostics: Boolean = true,
-      keepIdentifiers: Boolean = false
-    ): Subtraction =
-      copy(
-        left = left.duplicate(
-          keepLocations,
-          keepMetadata,
-          keepDiagnostics,
-          keepIdentifiers
-        ),
-        right = right.duplicate(
-          keepLocations,
-          keepMetadata,
-          keepDiagnostics,
-          keepIdentifiers
-        ),
-        location = if (keepLocations) location else None,
-        passData = if (keepMetadata) passData.duplicate else MetadataStorage(),
-        diagnostics =
-          if (keepDiagnostics) diagnostics.copy else DiagnosticStorage(),
-        id = if (keepIdentifiers) id else randomId
-      )
-
-    /** @inheritdoc */
-    override def setLocation(
-      location: Option[IdentifiedLocation]
-    ): Subtraction = copy(location = location)
-
-    /** @inheritdoc */
-    override def mapExpressions(
-      fn: Expression => Expression
-    ): Subtraction = {
-      copy(left = fn(left), right = fn(right))
-    }
-
-    /** @inheritdoc */
-    override def toString: String =
-      s"""
-         |`type`.Set.Subtraction(
-         |left = $left,
-         |right = $right,
-         |location = $location,
-         |passData = ${this.showPassData},
-         |diagnostics = $diagnostics,
-         |id = $id
-         |""".toSingleLine
-
-    /** @inheritdoc */
-    override def children: List[IR] = List(left, right)
-
-    /** @inheritdoc */
-    override def showCode(indent: Int): String =
-      s"(${left.showCode(indent)} \\ ${right.showCode(indent)})"
-  }
-
-  object Subtraction extends Info {
-    override val name: String = "\\"
-  }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/callable/InvokeMethodNode.java

@@ -30,6 +30,7 @@
 import org.enso.interpreter.runtime.data.EnsoDate;
 import org.enso.interpreter.runtime.data.EnsoDateTime;
 import org.enso.interpreter.runtime.data.EnsoDuration;
+import org.enso.interpreter.runtime.data.EnsoMultiValue;
 import org.enso.interpreter.runtime.data.EnsoTimeOfDay;
 import org.enso.interpreter.runtime.data.EnsoTimeZone;
 import org.enso.interpreter.runtime.data.Type;
@@ -208,9 +209,7 @@ Object doFunctionalDispatchUncachedSymbol(
     Type selfTpe = typesLibrary.getType(self);
     Function function = resolveFunction(symbol, selfTpe, methodResolverNode);
     if (function == null) {
-      var cause = onBoundary ? UnknownIdentifierException.create(symbol.getName()) : null;
-      var payload = EnsoContext.get(this).getBuiltins().error().makeNoSuchMethod(self, symbol);
-      throw new PanicException(payload, cause, this);
+      throw methodNotFound(symbol, self);
     }
     var resolvedFuncArgCount = function.getSchema().getArgumentsCount();
     CallArgumentInfo[] invokeFuncSchema = invokeFunctionNode.getSchema();
@@ -271,6 +270,32 @@ Object doFunctionalDispatchUncachedSymbol(
     return invokeFunctionNode.execute(function, frame, state, arguments);
   }
 
+  private PanicException methodNotFound(UnresolvedSymbol symbol, Object self) throws PanicException {
+    var cause = onBoundary ? UnknownIdentifierException.create(symbol.getName()) : null;
+    var payload = EnsoContext.get(this).getBuiltins().error().makeNoSuchMethod(self, symbol);
+    throw new PanicException(payload, cause, this);
+  }
+
+  @Specialization
+  Object doMultiValue(
+      VirtualFrame frame,
+      State state,
+      UnresolvedSymbol symbol,
+      EnsoMultiValue self,
+      Object[] arguments,
+      @Shared("methodResolverNode") @Cached MethodResolverNode methodResolverNode
+  ) {
+    var fnAndType = self.resolveSymbol(methodResolverNode, symbol);
+    if (fnAndType != null) {
+      var unwrapSelf = self.castTo(fnAndType.getRight());
+      assert unwrapSelf != null;
+      assert arguments[0] == self;
+      arguments[0] = unwrapSelf;
+      return execute(frame, state, symbol, unwrapSelf, arguments);
+    }
+    throw methodNotFound(symbol, self);
+  }
+
   @Specialization
   Object doDataflowError(
       VirtualFrame frame,
@@ -327,7 +352,7 @@ Function resolveWarningFunction(
           e);
     }
 
-    Type typeOfSymbol = symbol.resolveDeclaringType(types.getType(selfWithoutWarnings));
+    Type typeOfSymbol = symbol.resolveDeclaringType(this, types.getType(selfWithoutWarnings));
     Builtins builtins = EnsoContext.get(this).getBuiltins();
     if (typeOfSymbol == builtins.any()) {
       return symbol