--- a/mercurial/revsetlang.py	Tue Aug 29 11:25:22 2017 +0200
+++ b/mercurial/revsetlang.py	Wed Aug 30 22:32:47 2017 +0900
@@ -258,48 +258,6 @@
         return
     return x[2]
 
-# Constants for ordering requirement, used in getset():
-#
-# If 'define', any nested functions and operations MAY change the ordering of
-# the entries in the set (but if changes the ordering, it MUST ALWAYS change
-# it). If 'follow', any nested functions and operations MUST take the ordering
-# specified by the first operand to the '&' operator.
-#
-# For instance,
-#
-#   X & (Y | Z)
-#   ^   ^^^^^^^
-#   |   follow
-#   define
-#
-# will be evaluated as 'or(y(x()), z(x()))', where 'x()' can change the order
-# of the entries in the set, but 'y()', 'z()' and 'or()' shouldn't.
-#
-# 'any' means the order doesn't matter. For instance,
-#
-#   (X & Y) | ancestors(Z)
-#        ^              ^
-#        any            any
-#
-# For 'X & Y', 'X' decides order so the order of 'Y' does not matter. For
-# 'ancestors(Z)', Z's order does not matter since 'ancestors' does not care
-# about the order of its argument.
-#
-# Currently, most revsets do not care about the order, so 'define' is
-# equivalent to 'follow' for them, and the resulting order is based on the
-# 'subset' parameter passed down to them:
-#
-#   m = revset.match(..., order=defineorder)
-#   m(repo, subset)
-#           ^^^^^^
-#      For most revsets, 'define' means using the order this subset provides
-#
-# There are a few revsets that always redefine the order if 'define' is
-# specified: 'sort(X)', 'reverse(X)', 'x:y'.
-anyorder = 'any'        # don't care the order, could be even random-shuffled
-defineorder = 'define'  # ALWAYS redefine, or ALWAYS follow the current order
-followorder = 'follow'  # MUST follow the current order
-
 def _matchonly(revs, bases):
     """
     >>> f = lambda *args: _matchonly(*map(parse, args))