Cleanup Skylark types some more
Clarify the criterion for being a valid Skylark value;
stop claiming immutability is "the" criterion when Skylark now has mutable values;
stop relying on a reflection with a magic list (this also fixes the SkylarkShell build).
Clarify the criterion for determining immutable types when making a SkylarkNestedSet.
Clarify and use the criterion for being a valid Skylark dict key.
--
MOS_MIGRATED_REVID=103313934
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Runtime.java b/src/main/java/com/google/devtools/build/lib/syntax/Runtime.java
index 9230d6b..098836a 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Runtime.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Runtime.java
@@ -43,10 +43,23 @@
* There should be only one instance of this type to allow "== None" tests.
*/
@Immutable
- public static final class NoneType {
- @Override
- public String toString() { return "None"; }
+ public static final class NoneType implements SkylarkValue {
private NoneType() {}
+
+ @Override
+ public String toString() {
+ return "None";
+ }
+
+ @Override
+ public boolean isImmutable() {
+ return true;
+ }
+
+ @Override
+ public void write(Appendable buffer, char quotationMark) {
+ Printer.append(buffer, "None");
+ }
}
@SkylarkSignature(name = "None", returnType = NoneType.class,
