Better way of registering builtin functions (#255)

Interpreter/src/main/java/org/enso/interpreter/builder/ExpressionFactory.java

@@ -32,7 +32,6 @@ import org.enso.interpreter.node.controlflow.DefaultFallbackNode;
 import org.enso.interpreter.node.controlflow.FallbackNode;
 import org.enso.interpreter.node.controlflow.IfZeroNode;
 import org.enso.interpreter.node.controlflow.MatchNode;
-import org.enso.interpreter.node.expression.builtin.PrintNodeGen;
 import org.enso.interpreter.node.expression.constant.ConstructorNode;
 import org.enso.interpreter.node.expression.constant.DynamicSymbolNode;
 import org.enso.interpreter.node.expression.literal.IntegerLiteralNode;
@@ -370,17 +369,6 @@ public class ExpressionFactory implements AstExpressionVisitor<ExpressionNode> {
     return AssignmentNodeGen.create(expr.visit(this), slot);
   }
 
-  /**
-   * Creates a runtime node representing a print expression.
-   *
-   * @param body an expression that computes the value to print
-   * @return a runtime node representing the print
-   */
-  @Override
-  public ExpressionNode visitPrint(AstExpression body) {
-    return PrintNodeGen.create(body.visit(this));
-  }
-
   /**
    * Creates a runtime node representing a pattern match.
    *

Interpreter/src/main/java/org/enso/interpreter/node/ExpressionNode.java

@@ -14,7 +14,7 @@ import org.enso.interpreter.runtime.type.TypesGen;
  *
  * <p>Enso is an expression-oriented language, and hence doesn't have any statements. This means
  * that all expression execution will return a value, even if that is just the {@link
- * Builtins#UNIT} type.
+ * Builtins#unit()} type.
  *
  * <p>This class contains specialisations of the {@link #executeGeneric(VirtualFrame)
  * executeGeneric} method for various scenarios in order to improve performance.

Interpreter/src/main/java/org/enso/interpreter/node/expression/builtin/PrintNode.java

@@ -1,52 +1,62 @@
 package org.enso.interpreter.node.expression.builtin;
 
+import com.oracle.truffle.api.CallTarget;
 import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.RootCallTarget;
+import com.oracle.truffle.api.Truffle;
 import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.NodeInfo;
+import com.oracle.truffle.api.nodes.RootNode;
 import org.enso.interpreter.Language;
 import org.enso.interpreter.node.ExpressionNode;
 import org.enso.interpreter.runtime.Builtins;
 import org.enso.interpreter.runtime.Context;
+import org.enso.interpreter.runtime.callable.argument.ArgumentDefinition;
+import org.enso.interpreter.runtime.callable.function.ArgumentSchema;
+import org.enso.interpreter.runtime.callable.function.Function;
 
-import java.io.OutputStream;
 import java.io.PrintStream;
 
-/** This node allows for printing the result of an arbitrary expression to standard output. */
-@NodeInfo(shortName = "print", description = "Prints the value of child expression.")
-public abstract class PrintNode extends ExpressionNode {
-  @Child private ExpressionNode expression;
+/** This node allows for printing the result of arbitrary values to standard output. */
+@NodeInfo(shortName = "print", description = "Root of the IO.println method.")
+public abstract class PrintNode extends RootNode {
 
   /**
-   * Creates a node that prints the result of its expression.
+   * Creates a root node for the builtin IO.println method.
    *
-   * @param expression the expression to print the result of
+   * @param language the current {@link Language} instance.
    */
-  public PrintNode(ExpressionNode expression) {
-    this.expression = expression;
+  public PrintNode(Language language) {
+    super(language);
   }
 
-  /**
-   * Executes the print node.
-   *
-   * @param frame the stack frame for execution
-   * @return unit {@link Builtins#UNIT unit} type
-   */
   @Specialization
-  public Object doPrint(VirtualFrame frame, @CachedContext(Language.class) Context ctx) {
-    doPrint(ctx.getOut(), expression.executeGeneric(frame));
+  protected Object doPrint(VirtualFrame frame, @CachedContext(Language.class) Context ctx) {
+    doPrint(ctx.getOut(), Function.ArgumentsHelper.getPositionalArguments(frame.getArguments())[1]);
 
-    return Builtins.UNIT.newInstance();
+    return ctx.getUnit().newInstance();
   }
 
-  /**
-   * Prints the provided value to standard output.
-   *
-   * @param object the value to print
-   */
   @CompilerDirectives.TruffleBoundary
   private void doPrint(PrintStream out, Object object) {
     out.println(object);
   }
+
+  /**
+   * Creates a {@link Function} object ignoring its first argument and printing the second to the
+   * standard output.
+   *
+   * @param language the current {@link Language} instance
+   * @return a {@link Function} object wrapping the behavior of this node
+   */
+  public static Function toFunction(Language language) {
+    PrintNode node = PrintNodeGen.create(language);
+    RootCallTarget callTarget = Truffle.getRuntime().createCallTarget(node);
+    ArgumentSchema schema =
+        new ArgumentSchema(
+            new ArgumentDefinition(0, "this", false), new ArgumentDefinition(1, "value", false));
+    return new Function(callTarget, null, schema);
+  }
 }

Interpreter/src/main/java/org/enso/interpreter/node/scope/AssignmentNode.java

@@ -1,5 +1,6 @@
 package org.enso.interpreter.node.scope;
 
+import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.dsl.NodeChild;
 import com.oracle.truffle.api.dsl.NodeField;
 import com.oracle.truffle.api.dsl.Specialization;
@@ -7,8 +8,10 @@ import com.oracle.truffle.api.frame.FrameSlot;
 import com.oracle.truffle.api.frame.FrameSlotKind;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.NodeInfo;
+import org.enso.interpreter.Language;
 import org.enso.interpreter.node.ExpressionNode;
 import org.enso.interpreter.runtime.Builtins;
+import org.enso.interpreter.runtime.Context;
 
 /** This node represents an assignment to a variable in a given scope. */
 @NodeInfo(shortName = "=", description = "Assigns expression result to a variable.")
@@ -20,14 +23,16 @@ public abstract class AssignmentNode extends ExpressionNode {
    *
    * @param frame the frame to write to
    * @param value the value to write
-   * @return the {@link Builtins#UNIT unit} type
+   * @param ctx language context for global values access
+   * @return the unit type
    */
   @Specialization
-  protected Object writeLong(VirtualFrame frame, long value) {
+  protected Object writeLong(
+      VirtualFrame frame, long value, @CachedContext(Language.class) Context ctx) {
     frame.getFrameDescriptor().setFrameSlotKind(getFrameSlot(), FrameSlotKind.Long);
     frame.setLong(getFrameSlot(), value);
 
-    return Builtins.UNIT.newInstance();
+    return ctx.getUnit().newInstance();
   }
 
   /**
@@ -35,14 +40,16 @@ public abstract class AssignmentNode extends ExpressionNode {
    *
    * @param frame the frame to write to
    * @param value the value to write
-   * @return the {@link Builtins#UNIT unit} type
+   * @param ctx language context for global values access
+   * @return the unit type
    */
   @Specialization
-  protected Object writeObject(VirtualFrame frame, Object value) {
+  protected Object writeObject(
+      VirtualFrame frame, Object value, @CachedContext(Language.class) Context ctx) {
     frame.getFrameDescriptor().setFrameSlotKind(getFrameSlot(), FrameSlotKind.Object);
     frame.setObject(getFrameSlot(), value);
 
-    return Builtins.UNIT.newInstance();
+    return ctx.getUnit().newInstance();
   }
 
   /**

Interpreter/src/main/java/org/enso/interpreter/runtime/Builtins.java

@@ -1,24 +1,55 @@
 package org.enso.interpreter.runtime;
 
+import org.enso.interpreter.Language;
+import org.enso.interpreter.node.expression.builtin.PrintNode;
 import org.enso.interpreter.runtime.callable.argument.ArgumentDefinition;
 import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
 import org.enso.interpreter.runtime.scope.ModuleScope;
 
-/** Container class for static predefined atoms and their containing scope. */
+/** Container class for static predefined atoms, methods, and their containing scope. */
 public class Builtins {
-  public static final ModuleScope BUILTIN_SCOPE = new ModuleScope();
-  public static final AtomConstructor UNIT =
-      new AtomConstructor("Unit", BUILTIN_SCOPE).initializeFields();
-  public static final AtomConstructor NIL =
-      new AtomConstructor("Nil", BUILTIN_SCOPE).initializeFields();
-  public static final AtomConstructor CONS =
-      new AtomConstructor("Cons", BUILTIN_SCOPE)
-          .initializeFields(
-              new ArgumentDefinition(0, "head", false), new ArgumentDefinition(1, "rest", false));
+  private final ModuleScope scope;
+  private final AtomConstructor unit;
 
-  static {
-    BUILTIN_SCOPE.registerConstructor(Builtins.CONS);
-    BUILTIN_SCOPE.registerConstructor(Builtins.NIL);
-    BUILTIN_SCOPE.registerConstructor(Builtins.UNIT);
+  /**
+   * Creates an instance with builtin methods installed.
+   *
+   * @param language the current {@link Language} instance
+   */
+  public Builtins(Language language) {
+    scope = new ModuleScope();
+    unit = new AtomConstructor("Unit", scope).initializeFields();
+
+    AtomConstructor nil = new AtomConstructor("Nil", scope).initializeFields();
+    AtomConstructor cons =
+        new AtomConstructor("Cons", scope)
+            .initializeFields(
+                new ArgumentDefinition(0, "head", false), new ArgumentDefinition(1, "rest", false));
+    AtomConstructor io = new AtomConstructor("IO", scope).initializeFields();
+
+    scope.registerConstructor(cons);
+    scope.registerConstructor(nil);
+    scope.registerConstructor(unit);
+    scope.registerConstructor(io);
+
+    scope.registerMethod(io, "println", PrintNode.toFunction(language));
+  }
+
+  /**
+   * Returns the {@code Unit} atom constructor.
+   *
+   * @return the {@code Unit} atom constructor
+   */
+  public AtomConstructor unit() {
+    return unit;
+  }
+
+  /**
+   * Returns the builtin module scope.
+   *
+   * @return the builtin module scope
+   */
+  public ModuleScope getScope() {
+    return scope;
   }
 }

Interpreter/src/main/java/org/enso/interpreter/runtime/Context.java

@@ -20,6 +20,7 @@ import org.enso.interpreter.Language;
 import org.enso.interpreter.builder.ModuleScopeExpressionFactory;
 import org.enso.interpreter.node.EnsoRootNode;
 import org.enso.interpreter.node.ExpressionNode;
+import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
 import org.enso.interpreter.runtime.error.ModuleDoesNotExistException;
 import org.enso.interpreter.runtime.scope.ModuleScope;
 import org.enso.interpreter.util.ScalaConversions;
@@ -36,6 +37,7 @@ public class Context {
   private final Env environment;
   private final Map<String, Module> knownFiles;
   private final PrintStream out;
+  private final Builtins builtins;
 
   /**
    * Creates a new Enso context.
@@ -47,6 +49,7 @@ public class Context {
     this.language = language;
     this.environment = environment;
     this.out = new PrintStream(environment.out());
+    this.builtins = new Builtins(language);
 
     List<File> packagePaths = RuntimeOptions.getPackagesPaths(environment);
     // TODO [MK] Replace getTruffleFile with getInternalTruffleFile when Graal 19.3.0 comes out.
@@ -86,7 +89,7 @@ public class Context {
    * @return a call target which execution corresponds to the toplevel executable bits in the module
    */
   public CallTarget parse(Source source) {
-    return parse(source, new ModuleScope());
+    return parse(source, createScope());
   }
 
   /**
@@ -131,4 +134,29 @@ public class Context {
   public PrintStream getOut() {
     return out;
   }
+
+  /**
+   * Creates a new module scope that automatically imports all the builtin types and methods.
+   *
+   * @return a new module scope with automatic builtins dependency.
+   */
+  public ModuleScope createScope() {
+    ModuleScope moduleScope = new ModuleScope();
+    moduleScope.addImport(getBuiltins().getScope());
+    return moduleScope;
+  }
+
+  private Builtins getBuiltins() {
+    return builtins;
+  }
+
+  /**
+   * Returns the atom constructor corresponding to the {@code Unit} type, for builtin constructs
+   * that need to return an atom of this type.
+   *
+   * @return the builtin {@code Unit} atom constructor
+   */
+  public AtomConstructor getUnit() {
+    return getBuiltins().unit();
+  }
 }

Interpreter/src/main/java/org/enso/interpreter/runtime/Module.java

@@ -28,7 +28,7 @@ public class Module {
    */
   public ModuleScope requestParse(Context context) throws IOException {
     if (cachedScope == null) {
-      cachedScope = new ModuleScope();
+      cachedScope = context.createScope();
       context.parse(file, cachedScope);
     }
     return cachedScope;

Interpreter/src/main/java/org/enso/interpreter/runtime/callable/function/ArgumentSchema.java

@@ -48,7 +48,7 @@ public class ArgumentSchema {
    *
    * @param argumentInfos Definition site arguments information
    */
-  public ArgumentSchema(ArgumentDefinition[] argumentInfos) {
+  public ArgumentSchema(ArgumentDefinition... argumentInfos) {
     this(argumentInfos, new boolean[argumentInfos.length], new CallArgumentInfo[0]);
   }
 

Interpreter/src/main/java/org/enso/interpreter/runtime/scope/ModuleScope.java

@@ -1,6 +1,7 @@
 package org.enso.interpreter.runtime.scope;
 
 import org.enso.interpreter.runtime.Builtins;
+import org.enso.interpreter.runtime.Module;
 import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
 import org.enso.interpreter.runtime.callable.function.Function;
 
@@ -14,11 +15,6 @@ public class ModuleScope {
   private final Set<ModuleScope> imports = new HashSet<>();
   private final Set<ModuleScope> transitiveImports = new HashSet<>();
 
-  /** Creates a new scope. Every scope implicitly imports the builtin scope. */
-  public ModuleScope() {
-    imports.add(Builtins.BUILTIN_SCOPE);
-  }
-
   /**
    * Adds an Atom constructor definition to the module scope.
    *
@@ -81,9 +77,13 @@ public class ModuleScope {
    */
   public Function lookupMethodDefinition(AtomConstructor atom, String name) {
     Function definedWithAtom = atom.getDefinitionScope().getMethodMapFor(atom).get(name);
-    if (definedWithAtom != null) { return definedWithAtom; }
+    if (definedWithAtom != null) {
+      return definedWithAtom;
+    }
     Function definedHere = getMethodMapFor(atom).get(name);
-    if (definedHere != null) { return definedHere; }
+    if (definedHere != null) {
+      return definedHere;
+    }
     return transitiveImports.stream()
         .map(scope -> scope.getMethodMapFor(atom).get(name))
         .filter(Objects::nonNull)

Interpreter/src/main/scala/org/enso/interpreter/Parser.scala

@@ -41,8 +41,6 @@ trait AstExpressionVisitor[+T] {
 
   def visitAssignment(varName: String, expr: AstExpression): T
 
-  def visitPrint(body: AstExpression): T
-
   def visitMatch(
     target: AstExpression,
     branches: java.util.List[AstCase],
@@ -203,11 +201,6 @@ case class AstAssignment(name: String, body: AstExpression)
     visitor.visitAssignment(name, body)
 }
 
-case class AstPrint(body: AstExpression) extends AstExpression {
-  override def visit[T](visitor: AstExpressionVisitor[T]): T =
-    visitor.visitPrint(body)
-}
-
 case class AstIfZero(
   cond: AstExpression,
   ifTrue: AstExpression,
@@ -293,7 +286,7 @@ class EnsoParserInternal extends JavaTokenParsers {
     }
 
   def expression: Parser[AstExpression] =
-    desuspend | print | ifZero | matchClause | arith | function
+    desuspend | ifZero | matchClause | arith | function
 
   def functionCall: Parser[AstApply] =
     "@" ~> expression ~ (argList ?) ~ defaultSuspend ^^ {
@@ -313,8 +306,6 @@ class EnsoParserInternal extends JavaTokenParsers {
     case v ~ exp => AstAssignment(v, exp)
   }
 
-  def print: Parser[AstPrint] = "print:" ~> expression ^^ AstPrint
-
   def ifZero: Parser[AstIfZero] =
     "ifZero:" ~> "[" ~> (expression ~ ("," ~> expression ~ ("," ~> expression))) <~ "]" ^^ {
       case cond ~ (ift ~ iff) => AstIfZero(cond, ift, iff)

Interpreter/src/test/scala/org/enso/interpreter/test/semantic/LazyArgumentsTest.scala

@@ -8,7 +8,7 @@ class LazyArgumentsTest extends LanguageTest {
       """
         |@{
         |  foo = { |i, $x, $y| ifZero: [i, $x, $y] };
-        |  @foo [1, (print: 1), (print: 2)]
+        |  @foo [1, @println [@IO, 1], @println [@IO, 2]]
         |}
         |""".stripMargin
     noException should be thrownBy parse(code)
@@ -53,9 +53,9 @@ class LazyArgumentsTest extends LanguageTest {
         |Bar.method = { |x| 10 }
         |
         |@{
-        |  @method [@Foo, (print: 1)];
-        |  @method [@Bar, (print: 2)];
-        |  @method [@Foo, (print: 3)]
+        |  @method [@Foo, @println [@IO, 1]];
+        |  @method [@Bar, @println [@IO, 2]];
+        |  @method [@Foo, @println [@IO, 3]]
         |}
         |""".stripMargin
     eval(code)
@@ -68,8 +68,8 @@ class LazyArgumentsTest extends LanguageTest {
         |@{
         |  if = { |c, $ifT, $ifF| ifZero: [c, $ifT, $ifF] };
         |  foo = { |c| @if [c] };
-        |  @foo [0, (print: 1), (print: 2)];
-        |  @foo [1, (print: 3), (print: 4)]
+        |  @foo [0, @println [@IO, 1], @println [@IO, 2]];
+        |  @foo [1, @println [@IO, 3], @println [@IO, 4]]
         |}
         |""".stripMargin
     eval(code)