Implement print_err and readln (#754)

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

@@ -0,0 +1,61 @@
+package org.enso.interpreter.node.expression.builtin.io;
+
+import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
+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 java.io.PrintStream;
+import org.enso.interpreter.Language;
+import org.enso.interpreter.node.expression.builtin.BuiltinRootNode;
+import org.enso.interpreter.runtime.Context;
+import org.enso.interpreter.runtime.callable.argument.ArgumentDefinition;
+import org.enso.interpreter.runtime.callable.argument.ArgumentDefinition.ExecutionMode;
+import org.enso.interpreter.runtime.callable.function.Function;
+import org.enso.interpreter.runtime.callable.function.FunctionSchema.CallStrategy;
+import org.enso.interpreter.runtime.state.Stateful;
+
+@NodeInfo(shortName = "IO.print_err", description = "Prints its argument to standard error.")
+public abstract class PrintErrNode extends BuiltinRootNode {
+  PrintErrNode(Language language) {
+    super(language);
+  }
+
+  @Specialization
+  Stateful doPrint(VirtualFrame frame, @CachedContext(Language.class) Context ctx) {
+    print(ctx.getErr(), Function.ArgumentsHelper.getPositionalArguments(frame.getArguments())[1]);
+    Object state = Function.ArgumentsHelper.getState(frame.getArguments());
+
+    return new Stateful(state, ctx.getUnit().newInstance());
+  }
+
+  @TruffleBoundary
+  private void print(PrintStream err, Object object) {
+    err.println(object);
+  }
+
+  /**
+   * Creates a {@link Function} object ignoring its first argument and printing the second to the
+   * standard error stream.
+   *
+   * @param language the current {@link Language} instance
+   * @return a {@link Function} object wrapping the behavior of this node
+   */
+  public static Function makeFunction(Language language) {
+    return Function.fromBuiltinRootNode(
+        PrintErrNodeGen.create(language),
+        CallStrategy.ALWAYS_DIRECT,
+        new ArgumentDefinition(0, "this", ExecutionMode.EXECUTE),
+        new ArgumentDefinition(1, "value", ExecutionMode.EXECUTE));
+  }
+
+  /**
+   * Gets the source-level name of this node.
+   *
+   * @return the source-level name of this node
+   */
+  @Override
+  public String getName() {
+    return "IO.print_err";
+  }
+}

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

@@ -15,22 +15,22 @@ import org.enso.interpreter.runtime.callable.function.FunctionSchema;
 import org.enso.interpreter.runtime.state.Stateful;
 
 /** Allows for printing arbitrary values to the standard output. */
-@NodeInfo(shortName = "IO.println", description = "Root of the IO.println method.")
-public abstract class PrintNode extends BuiltinRootNode {
-  PrintNode(Language language) {
+@NodeInfo(shortName = "IO.println", description = "Prints its argument to standard out.")
+public abstract class PrintlnNode extends BuiltinRootNode {
+  PrintlnNode(Language language) {
     super(language);
   }
 
   @Specialization
   Stateful doPrint(VirtualFrame frame, @CachedContext(Language.class) Context ctx) {
-    doPrint(ctx.getOut(), Function.ArgumentsHelper.getPositionalArguments(frame.getArguments())[1]);
+    print(ctx.getOut(), Function.ArgumentsHelper.getPositionalArguments(frame.getArguments())[1]);
     Object state = Function.ArgumentsHelper.getState(frame.getArguments());
 
     return new Stateful(state, ctx.getUnit().newInstance());
   }
 
   @CompilerDirectives.TruffleBoundary
-  private void doPrint(PrintStream out, Object object) {
+  private void print(PrintStream out, Object object) {
     out.println(object);
   }
 
@@ -43,7 +43,7 @@ public abstract class PrintNode extends BuiltinRootNode {
    */
   public static Function makeFunction(Language language) {
     return Function.fromBuiltinRootNode(
-        PrintNodeGen.create(language),
+        PrintlnNodeGen.create(language),
         FunctionSchema.CallStrategy.ALWAYS_DIRECT,
         new ArgumentDefinition(0, "this", ArgumentDefinition.ExecutionMode.EXECUTE),
         new ArgumentDefinition(1, "value", ArgumentDefinition.ExecutionMode.EXECUTE));

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

@@ -0,0 +1,65 @@
+package org.enso.interpreter.node.expression.builtin.io;
+
+import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
+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 java.io.BufferedReader;
+import java.io.IOException;
+import org.enso.interpreter.Language;
+import org.enso.interpreter.node.expression.builtin.BuiltinRootNode;
+import org.enso.interpreter.runtime.Context;
+import org.enso.interpreter.runtime.callable.argument.ArgumentDefinition;
+import org.enso.interpreter.runtime.callable.argument.ArgumentDefinition.ExecutionMode;
+import org.enso.interpreter.runtime.callable.function.Function;
+import org.enso.interpreter.runtime.callable.function.FunctionSchema.CallStrategy;
+import org.enso.interpreter.runtime.error.RuntimeError;
+import org.enso.interpreter.runtime.state.Stateful;
+
+@NodeInfo(shortName = "IO.readln", description = "Reads a line from standard in.")
+public abstract class ReadlnNode extends BuiltinRootNode {
+  public ReadlnNode(Language language) {
+    super(language);
+  }
+
+  @Specialization
+  Stateful doRead(VirtualFrame frame, @CachedContext(Language.class) Context ctx) {
+    return read(ctx.getIn(), Function.ArgumentsHelper.getState(frame.getArguments()));
+  }
+
+  @TruffleBoundary
+  private Stateful read(BufferedReader in, Object state) {
+    try {
+      String str = in.readLine();
+
+      return new Stateful(state, str);
+    } catch (IOException e) {
+      return new Stateful(state, new RuntimeError("Empty input stream."));
+    }
+  }
+
+  /**
+   * Creates a {@link Function} object ignoring its first argument and reading from the standard
+   * input stream.
+   *
+   * @param language the current {@link Language} instance
+   * @return a {@link Function} object wrapping the behavior of this node
+   */
+  public static Function makeFunction(Language language) {
+    return Function.fromBuiltinRootNode(
+        ReadlnNodeGen.create(language),
+        CallStrategy.ALWAYS_DIRECT,
+        new ArgumentDefinition(0, "this", ExecutionMode.EXECUTE));
+  }
+
+  /**
+   * Gets the source-level name of this node.
+   *
+   * @return the source-level name of the node
+   */
+  @Override
+  public String getName() {
+    return "IO.readln";
+  }
+}

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

@@ -1,4 +1,4 @@
-package org.enso.interpreter.node.expression.builtin.io;
+package org.enso.interpreter.node.expression.builtin.system;
 
 import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.frame.VirtualFrame;
@@ -10,7 +10,7 @@ import org.enso.interpreter.runtime.callable.function.Function;
 import org.enso.interpreter.runtime.callable.function.FunctionSchema;
 import org.enso.interpreter.runtime.state.Stateful;
 
-@NodeInfo(shortName = "IO.nano_time", description = "Gets the nanosecond resolution system time.")
+@NodeInfo(shortName = "System.nano_time", description = "Gets the nanosecond resolution system time.")
 public final class NanoTimeNode extends BuiltinRootNode {
   private NanoTimeNode(Language language) {
     super(language);
@@ -47,6 +47,6 @@ public final class NanoTimeNode extends BuiltinRootNode {
    */
   @Override
   public String getName() {
-    return "IO.nano_time";
+    return "System.nano_time";
   }
 }

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

@@ -14,8 +14,10 @@ import org.enso.interpreter.node.expression.builtin.function.ExplicitCallFunctio
 import org.enso.interpreter.node.expression.builtin.interop.generic.*;
 import org.enso.interpreter.node.expression.builtin.interop.syntax.MethodDispatchNode;
 import org.enso.interpreter.node.expression.builtin.interop.syntax.ConstructorDispatchNode;
-import org.enso.interpreter.node.expression.builtin.io.NanoTimeNode;
-import org.enso.interpreter.node.expression.builtin.io.PrintNode;
+import org.enso.interpreter.node.expression.builtin.io.PrintErrNode;
+import org.enso.interpreter.node.expression.builtin.io.PrintlnNode;
+import org.enso.interpreter.node.expression.builtin.io.ReadlnNode;
+import org.enso.interpreter.node.expression.builtin.system.NanoTimeNode;
 import org.enso.interpreter.node.expression.builtin.interop.java.*;
 import org.enso.interpreter.node.expression.builtin.number.AddNode;
 import org.enso.interpreter.node.expression.builtin.number.DivideNode;
@@ -94,6 +96,7 @@ public class Builtins {
                 new ArgumentDefinition(0, "head", ArgumentDefinition.ExecutionMode.EXECUTE),
                 new ArgumentDefinition(1, "rest", ArgumentDefinition.ExecutionMode.EXECUTE));
     AtomConstructor io = new AtomConstructor("IO", scope).initializeFields();
+    AtomConstructor system = new AtomConstructor("System", scope).initializeFields();
     AtomConstructor panic = new AtomConstructor("Panic", scope).initializeFields();
     AtomConstructor error = new AtomConstructor("Error", scope).initializeFields();
     AtomConstructor state = new AtomConstructor("State", scope).initializeFields();
@@ -120,8 +123,11 @@ public class Builtins {
     scope.registerConstructor(java);
     scope.registerConstructor(createPolyglot(language));
 
-    scope.registerMethod(io, "println", PrintNode.makeFunction(language));
-    scope.registerMethod(io, "nano_time", NanoTimeNode.makeFunction(language));
+    scope.registerMethod(io, "println", PrintlnNode.makeFunction(language));
+    scope.registerMethod(io, "print_err", PrintErrNode.makeFunction(language));
+    scope.registerMethod(io, "readln", ReadlnNode.makeFunction(language));
+
+    scope.registerMethod(system, "nano_time", NanoTimeNode.makeFunction(language));
 
     scope.registerMethod(panic, "throw", PanicNode.makeFunction(language));
     scope.registerMethod(panic, "recover", CatchPanicNode.makeFunction(language));

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

@@ -3,7 +3,11 @@ package org.enso.interpreter.runtime;
 import com.oracle.truffle.api.TruffleFile;
 import com.oracle.truffle.api.TruffleLanguage;
 import com.oracle.truffle.api.TruffleLanguage.Env;
+import java.io.BufferedReader;
 import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.io.PrintStream;
 import java.util.List;
 import java.util.Map;
@@ -30,6 +34,8 @@ public class Context {
   private final Env environment;
   private final Compiler compiler;
   private final PrintStream out;
+  private final PrintStream err;
+  private final BufferedReader in;
   private final List<Package> packages;
 
   /**
@@ -42,6 +48,8 @@ public class Context {
     this.language = language;
     this.environment = environment;
     this.out = new PrintStream(environment.out());
+    this.err = new PrintStream(environment.err());
+    this.in = new BufferedReader(new InputStreamReader(environment.in()));
 
     List<File> packagePaths = OptionsHelper.getPackagesPaths(environment);
 
@@ -125,6 +133,24 @@ public class Context {
     return out;
   }
 
+  /**
+   * Returns the standard error stream for this context.
+   *
+   * @return the standard error stream for this context
+   */
+  public PrintStream getErr() {
+    return err;
+  }
+
+  /**
+   * Returns the standard input stream for this context.
+   *
+   * @return the standard input stream for this context
+   */
+  public BufferedReader getIn() {
+    return in;
+  }
+
   /**
    * Creates a new module scope that automatically imports all the builtin types and methods.
    *

engine/runtime/src/test/scala/org/enso/interpreter/test/InterpreterTest.scala

@@ -1,6 +1,11 @@
 package org.enso.interpreter.test
 
-import java.io.ByteArrayOutputStream
+import java.io.{
+  ByteArrayOutputStream,
+  PipedInputStream,
+  PipedOutputStream,
+  PrintStream
+}
 import java.util.UUID
 
 import com.oracle.truffle.api.instrumentation.EventBinding
@@ -72,12 +77,19 @@ trait InterpreterRunner {
         value.execute(l.map(_.asInstanceOf[AnyRef]): _*)
       )
   }
-  val output = new ByteArrayOutputStream()
+  val output       = new ByteArrayOutputStream()
+  val err          = new ByteArrayOutputStream()
+  val inOut        = new PipedOutputStream()
+  val inOutPrinter = new PrintStream(inOut, true)
+  val in           = new PipedInputStream(inOut)
+
   val ctx = Context
     .newBuilder(LanguageInfo.ID)
     .allowExperimentalOptions(true)
     .allowAllAccess(true)
     .out(output)
+    .err(err)
+    .in(in)
     .build()
   lazy val executionContext = new PolyglotContext(ctx)
 
@@ -127,12 +139,22 @@ trait InterpreterRunner {
     }
   }
 
+  def consumeErr: List[String] = {
+    val result = err.toString
+    err.reset()
+    result.linesIterator.toList
+  }
+
   def consumeOut: List[String] = {
     val result = output.toString
     output.reset()
     result.linesIterator.toList
   }
 
+  def feedInput(string: String): Unit = {
+    inOutPrinter.println(string)
+  }
+
   def getReplInstrument: ReplDebuggerInstrument = {
     ctx.getEngine.getInstruments
       .get(ReplDebuggerInstrument.INSTRUMENT_ID)

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/TextTest.scala

@@ -64,4 +64,31 @@ class TextTest extends InterpreterTest {
     eval(code)
     consumeOut shouldEqual List("\"Grzegorz Brzeczyszczykiewicz\"")
   }
+
+  "Text literals" should "be able to be printed to standard error" in {
+    val errString = "\"My error string\""
+    val resultStr = errString.drop(1).dropRight(1)
+
+    val code =
+      s"""
+        |main = IO.print_err $errString
+        |""".stripMargin
+
+    eval(code)
+    consumeErr shouldEqual List(resultStr)
+  }
+
+  "Text literals" should "be able to be read from standard in" in {
+    val inputString = "foobarbaz"
+
+    val code =
+      """
+        |main =
+        |    IO.readln + " yay!"
+        |""".stripMargin
+
+    feedInput(inputString)
+
+    eval(code) shouldEqual "foobarbaz yay!"
+  }
 }

lib/syntax/specialization/shared/src/test/scala/org/enso/syntax/text/ParserTest.scala

@@ -50,7 +50,6 @@ class ParserTest extends AnyFlatSpec with Matchers {
     val module = Parser().run(input)
     val idmap1 = module.idMap
     val idmap2 = Parser().run(new Reader(input), idmap1).idMap
-    println(module.zipWithOffset)
     assertSpan(input, module)
     assert(module.show() == new Reader(input).toString())
     assert(idmap1 == idmap2)