diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkPath.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkPath.java
index 72505fb..264a034 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkPath.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkPath.java
@@ -19,6 +19,8 @@
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import com.google.devtools.build.lib.vfs.Path;
 import java.io.IOException;
 
@@ -34,7 +36,7 @@
   category = SkylarkModuleCategory.NONE,
   doc = "A structure representing a file to be used inside a repository."
 )
-final class SkylarkPath {
+final class SkylarkPath implements SkylarkValue {
   private final Path path;
 
   SkylarkPath(Path path) {
@@ -118,4 +120,9 @@
   public String toString() {
     return path.toString();
   }
+
+  @Override
+  public void repr(SkylarkPrinter printer) {
+    printer.append(toString());
+  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/cmdline/PackageIdentifier.java b/src/main/java/com/google/devtools/build/lib/cmdline/PackageIdentifier.java
index 8640f26..e276793 100644
--- a/src/main/java/com/google/devtools/build/lib/cmdline/PackageIdentifier.java
+++ b/src/main/java/com/google/devtools/build/lib/cmdline/PackageIdentifier.java
@@ -17,6 +17,8 @@
 import com.google.common.collect.ComparisonChain;
 import com.google.common.collect.Interner;
 import com.google.devtools.build.lib.concurrent.BlazeInterners;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.Canonicalizer;
 import com.google.devtools.build.lib.vfs.PathFragment;
@@ -27,12 +29,13 @@
 /**
  * Uniquely identifies a package, given a repository name and a package's path fragment.
  *
- * <p>The repository the build is happening in is the <i>default workspace</i>, and is identified
- * by the workspace name "". Other repositories can be named in the WORKSPACE file.  These
- * workspaces are prefixed by {@literal @}.</p>
+ * <p>The repository the build is happening in is the <i>default workspace</i>, and is identified by
+ * the workspace name "". Other repositories can be named in the WORKSPACE file. These workspaces
+ * are prefixed by {@literal @}.
  */
 @Immutable
-public final class PackageIdentifier implements Comparable<PackageIdentifier>, Serializable {
+public final class PackageIdentifier
+    implements Comparable<PackageIdentifier>, Serializable, SkylarkValue {
 
   private static final Interner<PackageIdentifier> INTERNER = BlazeInterners.newWeakInterner();
 
@@ -216,4 +219,9 @@
         .compare(pkgName, that.pkgName)
         .result();
   }
+
+  @Override
+  public void repr(SkylarkPrinter printer) {
+    printer.repr(toString());
+  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/apple/AppleCommandLineOptions.java b/src/main/java/com/google/devtools/build/lib/rules/apple/AppleCommandLineOptions.java
index 748f1df..2256156 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/apple/AppleCommandLineOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/apple/AppleCommandLineOptions.java
@@ -26,6 +26,8 @@
 import com.google.devtools.build.lib.rules.apple.ApplePlatform.PlatformType;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import com.google.devtools.common.options.Converters.CommaSeparatedOptionListConverter;
 import com.google.devtools.common.options.EnumConverter;
 import com.google.devtools.common.options.Option;
@@ -406,7 +408,7 @@
             + "\"embedded\", and \"embedded_markers\""
   )
   @Immutable
-  public enum AppleBitcodeMode {
+  public enum AppleBitcodeMode implements SkylarkValue {
 
     /** Do not compile bitcode. */
     NONE("none", ImmutableList.<String>of()),
@@ -435,6 +437,11 @@
       return mode;
     }
 
+    @Override
+    public void repr(SkylarkPrinter printer) {
+      printer.append(mode);
+    }
+
     /** Returns the names of any crosstool features that correspond to this bitcode mode. */
     public ImmutableList<String> getFeatureNames() {
       return featureNames;
diff --git a/src/main/java/com/google/devtools/build/lib/rules/apple/ApplePlatform.java b/src/main/java/com/google/devtools/build/lib/rules/apple/ApplePlatform.java
index 8e047c3..d81e698 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/apple/ApplePlatform.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/apple/ApplePlatform.java
@@ -22,6 +22,8 @@
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import com.google.devtools.build.lib.util.Preconditions;
 import java.util.HashMap;
 import java.util.Locale;
@@ -34,7 +36,7 @@
   doc = "Distinguishes between various apple platforms."
 )
 @Immutable
-public enum ApplePlatform {
+public enum ApplePlatform implements SkylarkValue {
   IOS_DEVICE("ios_device", "iPhoneOS", PlatformType.IOS, true),
   IOS_SIMULATOR("ios_simulator", "iPhoneSimulator", PlatformType.IOS, false),
   MACOS("macos", "MacOSX", PlatformType.MACOS, true),
@@ -196,6 +198,11 @@
     return new SkylarkClassObject(constructor, fields);
   }
 
+  @Override
+  public void repr(SkylarkPrinter printer) {
+    printer.append(toString());
+  }
+
   /**
    * Value used to describe Apple platform "type". A {@link ApplePlatform} is implied from a
    * platform type (for example, watchOS) together with a cpu value (for example, armv7).
@@ -207,7 +214,7 @@
     doc = "Describes Apple platform \"type\", such as iOS, tvOS, macOS etc."
   )
   @Immutable
-  public enum PlatformType {
+  public enum PlatformType implements SkylarkValue {
     IOS("ios"),
     WATCHOS("watchos"),
     TVOS("tvos"),
@@ -253,5 +260,10 @@
       }
       return new SkylarkClassObject(constructor, fields);
     }
+
+    @Override
+    public void repr(SkylarkPrinter printer) {
+      printer.append(toString());
+    }
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/apple/DottedVersion.java b/src/main/java/com/google/devtools/build/lib/rules/apple/DottedVersion.java
index 2a38bfe..bdbc910 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/apple/DottedVersion.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/apple/DottedVersion.java
@@ -24,6 +24,8 @@
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import java.util.ArrayList;
 import java.util.Objects;
 import java.util.regex.Matcher;
@@ -38,7 +40,9 @@
  *
  * <p>Dotted versions are ordered using natural integer sorting on components in order from first to
  * last where any missing element is considered to have the value 0 if they don't contain any
- * non-numeric characters. For example: <pre>
+ * non-numeric characters. For example:
+ *
+ * <pre>
  *   3.1.25 > 3.1.1
  *   3.1.20 > 3.1.2
  *   3.1.1 > 3.1
@@ -51,7 +55,9 @@
  * component with a smaller integer. If the integers are the same, the alphabetic sequences are
  * compared lexicographically, and if <i>they</i> turn out to be the same, the final (optional)
  * integer is compared. As with the leading integer, this final integer is considered to be 0 if not
- * present. For example: <pre>
+ * present. For example:
+ *
+ * <pre>
  *   3.1.1 > 3.1.1beta3
  *   3.1.1beta1 > 3.1.0
  *   3.1 > 3.1.0alpha1
@@ -72,7 +78,7 @@
           + "1.2.3.4."
 )
 @Immutable
-public final class DottedVersion implements Comparable<DottedVersion> {
+public final class DottedVersion implements Comparable<DottedVersion>, SkylarkValue {
   private static final Splitter DOT_SPLITTER = Splitter.on('.');
   private static final Pattern COMPONENT_PATTERN = Pattern.compile("(\\d+)(?:([a-z]+)(\\d*))?");
   private static final String ILLEGAL_VERSION =
@@ -238,6 +244,11 @@
     return ZERO_COMPONENT;
   }
 
+  @Override
+  public void repr(SkylarkPrinter printer) {
+    printer.append(stringRepresentation);
+  }
+
   private static final class Component implements Comparable<Component> {
     private final int firstNumber;
     private final String alphaSequence;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Printer.java b/src/main/java/com/google/devtools/build/lib/syntax/Printer.java
index 12cc792..3a6c60d 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Printer.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Printer.java
@@ -20,6 +20,7 @@
 import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkValue;
 import com.google.devtools.build.lib.syntax.SkylarkList.Tuple;
+import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import java.io.IOException;
 import java.util.Formattable;
@@ -351,10 +352,10 @@
       } else if (o instanceof Integer || o instanceof Double) {
         this.append(o.toString());
 
-      } else if (o == Boolean.TRUE) {
+      } else if (Boolean.TRUE.equals(o)) {
         this.append("True");
 
-      } else if (o == Boolean.FALSE) {
+      } else if (Boolean.FALSE.equals(o)) {
         this.append("False");
 
       } else if (o instanceof Map<?, ?>) {
@@ -374,6 +375,9 @@
       } else if (o instanceof PathFragment) {
         this.append(((PathFragment) o).getPathString());
 
+      } else if (o instanceof Path) {
+        append(o.toString());
+
       } else if (o instanceof Class<?>) {
         this.append(EvalUtils.getDataTypeNameFromClass((Class<?>) o));