tree 763110af90985fcf2ee26d5f4f3ba6c9ed9d7967
parent cc5c24c3797395aa2779d6e052e03396da3c4c34
author Googler <noreply@google.com> 1573840834 -0800
committer Copybara-Service <copybara-worker@google.com> 1573840897 -0800

bazel syntax: simplify and optimize list, tuple, range

Sequence:
- is now an interface
- delete getContentsUnsafe: don't prescribe representation.
- delete unnecessary stub methods from StarlarkValue and AbstractList.
- delete abstract repeat method. It is defined only for list and tuple.

Tuple:
- now extends AbstractList
- manipulates an Object[] directly, eliminating ImmutableList intermediary
  ...yet getImmutableList avoids a copy using the toArray sharing trick.
- eliminate all unnecessary array copies
- isHashable and isImmutable iterate over Object[] directly, not List wrapper.

StarlarkList
- now extends AbstractList
- delete one overload of StarlarkList.wrapUnsafe
- manipulates an Object[] directly, eliminating ArrayList intermediary.
- eliminate all unnecessary array copies

RangeList:
- optimize equals() not to materialize the sequence
- merge RangeList and RangeListView
- delete unreachable repeat() method

Also:
- removed comment at Sequence.createImmutable.
  We should stop using StarlarkThread to mean Mutability.
  (Longer term, we should get rid of Mutability in favor of a per-object frozen bit.)
PiperOrigin-RevId: 280680660