Parser optimization: compare Id instances by object identity.

Id.__eq__ was near the top of the profile, so we don't want it to be
implemented in Python.

Also:

- Count generated code correctly now that we've moved things.

core/id_kind.py

@@ -24,7 +24,11 @@ def IdName(id_):
  return _ID_NAMES[id_.enum_value]


# Save memory by keeping one instance.

# Keep one instance of each Id, to save memory and enable comparison by
# OBJECT IDENTITY.
# Do NOT create any any more instances of them!  Always used IdInstance().

# TODO: Fold this into ASDL, which will enforce this?

_ID_INSTANCES = {}  # int -> Id
@@ -44,15 +48,6 @@ class Id(object):
  def __init__(self, enum_value):
    self.enum_value = enum_value

  def __eq__(self, other):
    return self.enum_value == other.enum_value

  def __ne__(self, other):
    return self.enum_value != other.enum_value

  def __hash__(self):
    return hash(self.enum_value)

  def __repr__(self):
    return IdName(self)

core/id_kind_test.py

@@ -61,9 +61,8 @@ def testTokens(self):
    self.assertEqual(Kind.BoolBinary, LookupKind(t.id))

  def testEquality(self):
    # OK WTF!!!!
    left = Id(198)
    right = Id(198)
    left = id_kind.IdInstance(198)
    right = id_kind.IdInstance(198)
    print(left, right)
    print(left == right)
    self.assertEqual(left, right)

native/fastlex_test.py

@@ -11,6 +11,7 @@

import unittest

from core import id_kind
from core.id_kind import Id
from osh import ast_ as ast

@@ -21,7 +22,7 @@

def MatchToken(lex_mode, line, start_pos):
  tok_type, end_pos = fastlex.MatchToken(lex_mode.enum_id, line, start_pos)
  return Id(tok_type), end_pos
  return id_kind.IdInstance(tok_type), end_pos


def TokenizeLineOuter(line):

scripts/count.sh

@@ -49,7 +49,7 @@ all() {
  echo

  echo 'GENERATED CODE'
  wc -l _devbuild/*.py _devbuild/gen/* | sort --numeric
  wc -l _devbuild/gen/*.{py,h} | sort --numeric
  echo

  echo 'TOOLS'