Follow up for trace pretty printing (#1227)

pkl-core/src/main/java/org/pkl/core/Analyzer.java

@@ -57,7 +57,7 @@ public class Analyzer {
       @Nullable Path moduleCacheDir,
       @Nullable DeclaredDependencies projectDependencies,
       HttpClient httpClient,
-      @Nullable TraceMode traceMode) {
+      TraceMode traceMode) {
     this.transformer = transformer;
     this.color = color;
     this.securityManager = securityManager;

pkl-core/src/main/java/org/pkl/core/EvaluatorBuilder.java

@@ -68,7 +68,7 @@ public final class EvaluatorBuilder {
 
   private @Nullable DeclaredDependencies dependencies;
 
-  private @Nullable TraceMode traceMode;
+  private TraceMode traceMode = TraceMode.COMPACT;
 
   private EvaluatorBuilder() {}
 

pkl-core/src/main/java/org/pkl/core/EvaluatorImpl.java

@@ -82,7 +82,7 @@ public class EvaluatorImpl implements Evaluator {
       @Nullable Path moduleCacheDir,
       @Nullable DeclaredDependencies projectDependencies,
       @Nullable String outputFormat,
-      @Nullable TraceMode traceMode) {
+      TraceMode traceMode) {
 
     securityManager = manager;
     frameTransformer = transformer;

pkl-core/src/main/java/org/pkl/core/Loggers.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -80,6 +80,13 @@ public final class Loggers {
   }
 
   private static String formatMessage(String level, String message, StackFrame frame) {
-    return "pkl: " + level + ": " + message + " (" + frame.getModuleUri() + ')';
+    return "pkl: "
+        + level
+        + ": "
+        + message
+        + (message.endsWith("\n") ? "" : " ")
+        + "("
+        + frame.getModuleUri()
+        + ')';
   }
 }

pkl-core/src/main/java/org/pkl/core/ast/expression/unary/TraceNode.java

@@ -18,8 +18,9 @@ package org.pkl.core.ast.expression.unary;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.source.SourceSection;
+import java.util.Arrays;
+import java.util.stream.Collectors;
 import org.pkl.core.ast.ExpressionNode;
-import org.pkl.core.evaluatorSettings.TraceMode;
 import org.pkl.core.runtime.*;
 
 public final class TraceNode extends ExpressionNode {
@@ -27,9 +28,8 @@ public final class TraceNode extends ExpressionNode {
 
   private static final int MAX_RENDERER_LENGTH = 1000000;
 
-  private final VmValueRenderer singleLineRenderer =
-      VmValueRenderer.singleLine(MAX_RENDERER_LENGTH);
-  private final VmValueRenderer multiLineRenderer = VmValueRenderer.multiLine(MAX_RENDERER_LENGTH);
+  private final VmValueRenderer compactRenderer = VmValueRenderer.singleLine(MAX_RENDERER_LENGTH);
+  private final VmValueRenderer prettyRenderer = VmValueRenderer.multiLine(Integer.MAX_VALUE);
 
   public TraceNode(SourceSection sourceSection, ExpressionNode valueNode) {
     super(sourceSection);
@@ -45,29 +45,23 @@ public final class TraceNode extends ExpressionNode {
 
   @TruffleBoundary
   private void doTrace(Object value, VmContext context) {
-    // If traces are disabled, returns early.
-    if (context.getTraceMode() == TraceMode.HIDDEN) {
-      return;
-    }
-    if (value instanceof VmObjectLike objectLike) {
-      try {
-        objectLike.force(true, true);
-      } catch (VmException ignored) {
-      }
-    }
-
+    VmValue.force(value, true);
     var sourceSection = valueNode.getSourceSection();
-    String renderedValue;
-    if (context.getTraceMode() == TraceMode.PRETTY) {
-      renderedValue = multiLineRenderer.render(value);
-    } else {
-      renderedValue = singleLineRenderer.render(value);
-    }
+    var lhs = sourceSection.isAvailable() ? sourceSection.getCharacters().toString() : "<value>";
     var message =
-        (sourceSection.isAvailable() ? sourceSection.getCharacters() : "<value")
-            + " = "
-            + renderedValue;
-
+        switch (context.getTraceMode()) {
+          case COMPACT -> lhs + " = " + compactRenderer.render(value);
+          case PRETTY -> {
+            var rhs = prettyRenderer.render(value);
+            yield (lhs.contains("\n") ? "\n" + addIndent(lhs, "  ") + "\n=" : lhs + " =")
+                + (rhs.contains("\n") ? "\n" + addIndent(rhs, "  ") : " " + rhs)
+                + "\n";
+          }
+        };
     context.getLogger().trace(message, VmUtils.createStackFrame(sourceSection, null));
   }
+
+  private static String addIndent(String s, String indent) {
+    return Arrays.stream(s.split("\n")).map((it) -> indent + it).collect(Collectors.joining("\n"));
+  }
 }

pkl-core/src/main/java/org/pkl/core/evaluatorSettings/TraceMode.java

@@ -17,10 +17,8 @@ package org.pkl.core.evaluatorSettings;
 
 /** Dictates the rendering of calls to the trace() method within Pkl. */
 public enum TraceMode {
-  /** All trace() calls will not be emitted to stderr. */
-  HIDDEN,
   /** All structures passed to trace() will be emitted on a single line. */
-  DEFAULT,
+  COMPACT,
   /** All structures passed to trace() will be indented and emitted across multiple lines. */
   PRETTY
 }

pkl-core/src/main/java/org/pkl/core/repl/ReplServer.java

@@ -84,7 +84,7 @@ public class ReplServer implements AutoCloseable {
       Path workingDir,
       StackFrameTransformer frameTransformer,
       boolean color,
-      @Nullable TraceMode traceMode) {
+      TraceMode traceMode) {
 
     this.workingDir = workingDir;
     this.securityManager = securityManager;

pkl-core/src/main/java/org/pkl/core/runtime/StdLibModule.java

@@ -22,6 +22,7 @@ import java.util.Map;
 import org.pkl.core.Loggers;
 import org.pkl.core.SecurityManagers;
 import org.pkl.core.StackFrameTransformers;
+import org.pkl.core.evaluatorSettings.TraceMode;
 import org.pkl.core.http.HttpClient;
 import org.pkl.core.module.ModuleKeyFactories;
 import org.pkl.core.module.ModuleKeys;
@@ -50,7 +51,7 @@ public abstract class StdLibModule {
                       null,
                       null,
                       null,
-                      null));
+                      TraceMode.COMPACT));
               var language = VmLanguage.get(null);
               var moduleKey = ModuleKeys.standardLibrary(uri);
               var source = VmUtils.loadSource((ResolvedModuleKey) moduleKey);

pkl-core/src/main/java/org/pkl/core/runtime/VmContext.java

@@ -66,7 +66,7 @@ public final class VmContext {
         @Nullable String outputFormat,
         @Nullable PackageResolver packageResolver,
         @Nullable ProjectDependenciesManager projectDependenciesManager,
-        @Nullable TraceMode traceMode) {
+        TraceMode traceMode) {
 
       this.frameTransformer = frameTransformer;
       this.securityManager = securityManager;
@@ -148,7 +148,7 @@ public final class VmContext {
     return holder.projectDependenciesManager;
   }
 
-  public @Nullable TraceMode getTraceMode() {
+  public TraceMode getTraceMode() {
     return holder.traceMode;
   }
 }