Automatically force all-defaulted functions (#3414)

This changes the interpreter to treat functions with all-defaulted args as thunks. Seems to have no performance impact in compiled code.

CHANGELOG.md

@@ -185,6 +185,7 @@
 - [Fixed compiler issue related to module cache.][3367]
 - [Fixed execution of defaulted arguments of Atom Constructors][3358]
 - [Converting Enso Date to java.time.LocalDate and back][3374]
+- [Functions with all-defaulted arguments now execute automatically][3414]
 
 [3227]: https://github.com/enso-org/enso/pull/3227
 [3248]: https://github.com/enso-org/enso/pull/3248
@@ -195,6 +196,7 @@
 [3367]: https://github.com/enso-org/enso/pull/3367
 [3374]: https://github.com/enso-org/enso/pull/3374
 [3412]: https://github.com/enso-org/enso/pull/3412
+[3414]: https://github.com/enso-org/enso/pull/3414
 [3417]: https://github.com/enso-org/enso/pull/3417
 
 # Enso 2.0.0-alpha.18 (2021-10-12)

engine/runtime/src/main/java/org/enso/interpreter/node/BaseNode.java

@@ -18,7 +18,13 @@ public enum TailStatus {
     /** Node is in a tail position and marked as a tail call. */
     TAIL_LOOP,
     /** Node is not in a tail position. */
-    NOT_TAIL
+    NOT_TAIL;
+
+    private static final int NUMBER_OF_VALUES = values().length;
+
+    public static int numberOfValues() {
+      return NUMBER_OF_VALUES;
+    }
   }
 
   private @CompilationFinal TailStatus tailStatus = TailStatus.NOT_TAIL;

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

@@ -5,7 +5,6 @@
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.Node;
-import com.oracle.truffle.api.profiles.ConditionProfile;
 import com.oracle.truffle.api.source.SourceSection;
 import java.util.UUID;
 import java.util.concurrent.locks.Lock;
@@ -17,7 +16,6 @@
 import org.enso.interpreter.runtime.callable.UnresolvedConversion;
 import org.enso.interpreter.runtime.callable.UnresolvedSymbol;
 import org.enso.interpreter.runtime.callable.argument.CallArgumentInfo;
-import org.enso.interpreter.runtime.callable.argument.Thunk;
 import org.enso.interpreter.runtime.callable.atom.Atom;
 import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
 import org.enso.interpreter.runtime.callable.function.Function;

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

@@ -41,10 +41,9 @@ private Object executeArguments(
       Object state,
       ThunkExecutorNode thunkExecutorNode) {
     for (int i = 0; i < mapping.getArgumentShouldExecute().length; i++) {
-      if (TypesGen.isThunk(arguments[i]) && mapping.getArgumentShouldExecute()[i]) {
+      if (mapping.getArgumentShouldExecute()[i]) {
         Stateful result =
-            thunkExecutorNode.executeThunk(
-                TypesGen.asThunk(arguments[i]), state, BaseNode.TailStatus.NOT_TAIL);
+            thunkExecutorNode.executeThunk(arguments[i], state, BaseNode.TailStatus.NOT_TAIL);
         arguments[i] = result.getValue();
         state = result.getState();
       }

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

@@ -45,17 +45,17 @@ public static ReadArgumentNode build(int position, ExpressionNode defaultValue)
    */
   @Override
   public Object executeGeneric(VirtualFrame frame) {
-    Object argument = Function.ArgumentsHelper.getPositionalArguments(frame.getArguments())[index];
+    Object arguments[] = Function.ArgumentsHelper.getPositionalArguments(frame.getArguments());
 
     if (defaultValue == null) {
-      return argument;
+      return arguments[index];
     }
 
     // Note [Handling Argument Defaults]
-    if (defaultingProfile.profile(argument == null)) {
+    if (defaultingProfile.profile(arguments.length <= index || arguments[index] == null)) {
       return defaultValue.executeGeneric(frame);
     } else {
-      return argument;
+      return arguments[index];
     }
   }
 

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

@@ -4,7 +4,7 @@
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.NodeInfo;
 import org.enso.interpreter.node.ExpressionNode;
-import org.enso.interpreter.runtime.callable.argument.Thunk;
+import org.enso.interpreter.runtime.callable.function.Function;
 
 /** This node is responsible for wrapping a call target in a {@link Thunk} at execution time. */
 @NodeInfo(shortName = "CreateThunk", description = "Wraps a call target in a thunk at runtime")
@@ -34,6 +34,6 @@ public static CreateThunkNode build(RootCallTarget callTarget) {
    */
   @Override
   public Object executeGeneric(VirtualFrame frame) {
-    return new Thunk(this.callTarget, frame.materialize());
+    return Function.thunk(this.callTarget, frame.materialize());
   }
 }

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

@@ -7,7 +7,6 @@
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.NodeInfo;
 import org.enso.interpreter.node.ExpressionNode;
-import org.enso.interpreter.runtime.callable.argument.Thunk;
 import org.enso.interpreter.runtime.state.Stateful;
 
 /** Node responsible for handling user-requested thunks forcing. */

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

@@ -7,12 +7,14 @@
 import com.oracle.truffle.api.nodes.Node;
 import org.enso.interpreter.Constants;
 import org.enso.interpreter.node.BaseNode;
+import org.enso.interpreter.node.callable.InvokeCallableNode;
+import org.enso.interpreter.node.callable.dispatch.IndirectInvokeFunctionNode;
+import org.enso.interpreter.node.callable.dispatch.InvokeFunctionNode;
 import org.enso.interpreter.node.callable.dispatch.LoopingCallOptimiserNode;
-import org.enso.interpreter.runtime.callable.argument.Thunk;
+import org.enso.interpreter.runtime.callable.argument.CallArgumentInfo;
 import org.enso.interpreter.runtime.callable.function.Function;
 import org.enso.interpreter.runtime.control.TailCallException;
 import org.enso.interpreter.runtime.state.Stateful;
-import org.enso.interpreter.runtime.type.TypesGen;
 
 /** Node responsible for executing (forcing) thunks passed to it as runtime values. */
 @GenerateUncached
@@ -40,57 +42,102 @@ public static ThunkExecutorNode build() {
    */
   public abstract Stateful executeThunk(Object thunk, Object state, BaseNode.TailStatus isTail);
 
-  static boolean isThunk(Object th) {
-    return TypesGen.isThunk(th);
-  }
-
-  @Specialization(guards = "!isThunk(thunk)")
-  Stateful doOther(Object thunk, Object state, BaseNode.TailStatus isTail) {
-    return new Stateful(state, thunk);
+  boolean sameCallTarget(DirectCallNode callNode, Function function) {
+    return function.getCallTarget() == callNode.getCallTarget();
   }
 
   @Specialization(
-      guards = "callNode.getCallTarget() == thunk.getCallTarget()",
+      guards = {"function.isThunk()", "sameCallTarget(callNode, function)"},
       limit = Constants.CacheSizes.THUNK_EXECUTOR_NODE)
   Stateful doCached(
-      Thunk thunk,
+      Function function,
       Object state,
       BaseNode.TailStatus isTail,
-      @Cached("create(thunk.getCallTarget())") DirectCallNode callNode,
+      @Cached("create(function.getCallTarget())") DirectCallNode callNode,
       @Cached LoopingCallOptimiserNode loopingCallOptimiserNode) {
     CompilerAsserts.partialEvaluationConstant(isTail);
     if (isTail != BaseNode.TailStatus.NOT_TAIL) {
-      return (Stateful) callNode.call(Function.ArgumentsHelper.buildArguments(thunk, state));
+      return (Stateful) callNode.call(Function.ArgumentsHelper.buildArguments(function, state));
     } else {
       try {
-        return (Stateful) callNode.call(Function.ArgumentsHelper.buildArguments(thunk, state));
+        return (Stateful) callNode.call(Function.ArgumentsHelper.buildArguments(function, state));
       } catch (TailCallException e) {
         return loopingCallOptimiserNode.executeDispatch(
             e.getFunction(), e.getCallerInfo(), e.getState(), e.getArguments());
       }
     }
   }
 
-  @Specialization(replaces = "doCached")
+  @Specialization(replaces = "doCached", guards = "function.isThunk()")
   Stateful doUncached(
-      Thunk thunk,
+      Function function,
       Object state,
       BaseNode.TailStatus isTail,
       @Cached IndirectCallNode callNode,
       @Cached LoopingCallOptimiserNode loopingCallOptimiserNode) {
     if (isTail != BaseNode.TailStatus.NOT_TAIL) {
       return (Stateful)
           callNode.call(
-              thunk.getCallTarget(), Function.ArgumentsHelper.buildArguments(thunk, state));
+              function.getCallTarget(), Function.ArgumentsHelper.buildArguments(function, state));
     } else {
       try {
         return (Stateful)
             callNode.call(
-                thunk.getCallTarget(), Function.ArgumentsHelper.buildArguments(thunk, state));
+                function.getCallTarget(), Function.ArgumentsHelper.buildArguments(function, state));
       } catch (TailCallException e) {
         return loopingCallOptimiserNode.executeDispatch(
             e.getFunction(), e.getCallerInfo(), e.getState(), e.getArguments());
       }
     }
   }
+
+  static InvokeFunctionNode buildInvokeFunctionNode(BaseNode.TailStatus tailStatus) {
+    var node =
+        InvokeFunctionNode.build(
+            new CallArgumentInfo[0],
+            InvokeCallableNode.DefaultsExecutionMode.EXECUTE,
+            InvokeCallableNode.ArgumentsExecutionMode.EXECUTE);
+    node.setTailStatus(tailStatus);
+    return node;
+  }
+
+  static int numberOfTailStatuses() {
+    return BaseNode.TailStatus.numberOfValues();
+  }
+
+  @Specialization(
+      guards = {"!fn.isThunk()", "fn.isFullyApplied()", "isTail == cachedIsTail"},
+      limit = "numberOfTailStatuses()")
+  Stateful doCachedFn(
+      Function fn,
+      Object state,
+      BaseNode.TailStatus isTail,
+      @Cached("isTail") BaseNode.TailStatus cachedIsTail,
+      @Cached("buildInvokeFunctionNode(cachedIsTail)") InvokeFunctionNode invokeFunctionNode) {
+    return invokeFunctionNode.execute(fn, null, state, new Object[0]);
+  }
+
+  @Specialization(
+      guards = {"!fn.isThunk()", "fn.isFullyApplied()"},
+      replaces = {"doCachedFn"})
+  Stateful doUncachedFn(
+      Function fn,
+      Object state,
+      BaseNode.TailStatus isTail,
+      @Cached IndirectInvokeFunctionNode invokeFunctionNode) {
+    return invokeFunctionNode.execute(
+        fn,
+        null,
+        state,
+        new Object[0],
+        new CallArgumentInfo[0],
+        InvokeCallableNode.DefaultsExecutionMode.EXECUTE,
+        InvokeCallableNode.ArgumentsExecutionMode.EXECUTE,
+        isTail);
+  }
+
+  @Fallback
+  Stateful doOther(Object thunk, Object state, BaseNode.TailStatus isTail) {
+    return new Stateful(state, thunk);
+  }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/bool/IfThenElseNode.java

@@ -7,7 +7,6 @@
 import org.enso.interpreter.dsl.Suspend;
 import org.enso.interpreter.node.BaseNode;
 import org.enso.interpreter.node.callable.thunk.ThunkExecutorNode;
-import org.enso.interpreter.runtime.callable.argument.Thunk;
 import org.enso.interpreter.runtime.state.Stateful;
 
 @BuiltinMethod(

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/function/ApplicationOperator.java

@@ -8,7 +8,6 @@
 import org.enso.interpreter.node.BaseNode;
 import org.enso.interpreter.node.callable.InvokeCallableNode;
 import org.enso.interpreter.runtime.callable.argument.CallArgumentInfo;
-import org.enso.interpreter.runtime.callable.argument.Thunk;
 import org.enso.interpreter.runtime.callable.function.Function;
 import org.enso.interpreter.runtime.state.Stateful;
 

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/NewAtomInstanceNode.java

@@ -5,7 +5,6 @@
 import org.enso.interpreter.runtime.callable.atom.Atom;
 import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
 import org.enso.interpreter.runtime.data.Array;
-import org.enso.interpreter.runtime.type.TypesGen;
 
 @BuiltinMethod(
     type = "Meta",

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/runtime/NoInlineNode.java

@@ -7,7 +7,6 @@
 import org.enso.interpreter.dsl.Suspend;
 import org.enso.interpreter.node.BaseNode;
 import org.enso.interpreter.node.callable.thunk.ThunkExecutorNode;
-import org.enso.interpreter.runtime.callable.argument.Thunk;
 import org.enso.interpreter.runtime.state.Stateful;
 
 @BuiltinMethod(

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/thread/WithInterruptHandlerNode.java

@@ -6,7 +6,6 @@
 import org.enso.interpreter.dsl.Suspend;
 import org.enso.interpreter.node.BaseNode;
 import org.enso.interpreter.node.callable.thunk.ThunkExecutorNode;
-import org.enso.interpreter.runtime.callable.argument.Thunk;
 import org.enso.interpreter.runtime.control.ThreadInterruptedException;
 import org.enso.interpreter.runtime.state.Stateful;
 

engine/runtime/src/main/java/org/enso/interpreter/node/expression/debug/EvalNode.java

@@ -15,7 +15,7 @@
 import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
 import org.enso.interpreter.runtime.Context;
 import org.enso.interpreter.runtime.callable.CallerInfo;
-import org.enso.interpreter.runtime.callable.argument.Thunk;
+import org.enso.interpreter.runtime.callable.function.Function;
 import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.scope.LocalScope;
 import org.enso.interpreter.runtime.scope.ModuleScope;
@@ -98,7 +98,7 @@ Stateful doCached(
               "parseExpression(callerInfo.getLocalScope(), callerInfo.getModuleScope(), expressionStr)")
           RootCallTarget cachedCallTarget,
       @Cached("build()") ThunkExecutorNode thunkExecutorNode) {
-    Thunk thunk = new Thunk(cachedCallTarget, callerInfo.getFrame());
+    Function thunk = Function.thunk(cachedCallTarget, callerInfo.getFrame());
     return thunkExecutorNode.executeThunk(thunk, state, getTailStatus());
   }
 
@@ -114,7 +114,7 @@ Stateful doUncached(
             callerInfo.getLocalScope(),
             callerInfo.getModuleScope(),
             toJavaStringNode.execute(expression));
-    Thunk thunk = new Thunk(callTarget, callerInfo.getFrame());
+    Function thunk = Function.thunk(callTarget, callerInfo.getFrame());
     return thunkExecutorNode.executeThunk(thunk, state, getTailStatus());
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/runtime/builtin/Builtins.java

@@ -16,7 +16,6 @@
 import org.enso.interpreter.node.expression.builtin.error.CaughtPanicConvertToDataflowErrorMethodGen;
 import org.enso.interpreter.node.expression.builtin.error.GetAttachedStackTraceMethodGen;
 import org.enso.interpreter.node.expression.builtin.error.ThrowPanicMethodGen;
-import org.enso.interpreter.node.expression.builtin.function.ExplicitCallFunctionMethodGen;
 import org.enso.interpreter.node.expression.builtin.interop.java.AddToClassPathMethodGen;
 import org.enso.interpreter.node.expression.builtin.interop.java.LookupClassMethodGen;
 import org.enso.interpreter.node.expression.builtin.io.GetCwdMethodGen;
@@ -191,8 +190,6 @@ public Builtins(Context context) {
     scope.registerMethod(debug, MethodNames.Debug.EVAL, DebugEvalMethodGen.makeFunction(language));
     scope.registerMethod(debug, "breakpoint", DebugBreakpointMethodGen.makeFunction(language));
 
-    scope.registerMethod(function, "call", ExplicitCallFunctionMethodGen.makeFunction(language));
-
     scope.registerMethod(any, "to_text", AnyToTextMethodGen.makeFunction(language));
     scope.registerMethod(any, "to_display_text", AnyToDisplayTextMethodGen.makeFunction(language));
 

engine/runtime/src/main/java/org/enso/interpreter/runtime/callable/argument/ArgumentDefinition.java

@@ -4,7 +4,7 @@
 import org.enso.interpreter.node.ExpressionNode;
 
 /** Tracks the specifics about how arguments are defined at the callable definition site. */
-public class ArgumentDefinition {
+public final class ArgumentDefinition {
 
   /** Represents the mode of passing this argument to the function. */
   public enum ExecutionMode {

engine/runtime/src/main/java/org/enso/interpreter/runtime/callable/argument/CallArgument.java

@@ -3,7 +3,7 @@
 import org.enso.interpreter.node.ExpressionNode;
 
 /** Tracks the specifics about how arguments are specified at a call site. */
-public class CallArgument {
+public final class CallArgument {
   private final String name;
   private final ExpressionNode expression;