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#
# tree.py - functions to build trees from lists
#
# Paul Fisher <rao@gnu.org>
#
# Copyright 1999 Red Hat, Inc.
#
# This software may be freely redistributed under the terms of the GNU
# library public license.
#
# You should have received a copy of the GNU Library Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
# Uh. Don't ask me what this does. It's Paul's fault.
def build_tree (x):
if (x == ()): return ()
if (len (x) == 1): return (x[0],)
else: return (x[0], build_tree (x[1:]))
def merge (a, b):
if a == (): return build_tree (b)
if b == (): return a
if b[0] == a[0]:
if len (a) > 1 and isinstance (a[1], type (())):
return (a[0],) + (merge (a[1], b[1:]),) + a[2:]
elif b[1:] == (): return a
else: return (a[0],) + (build_tree (b[1:]),) + a[1:]
else:
return (a[0],) + merge (a[1:], b)
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