# Copyright (C) 2018-2020 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import sys
import gdb
import gdb.types

# Following is for Python 3 compatibility...
if sys.version_info[0] > 2:
    long = int


class cons_pp(object):
  def __init__(self, val):
    self._val = val

  def to_string(self):
    if long(self._val) == 0:
      return "nil"
    elif long(self._val['type']) == 0:
      return "( . )"
    else:
      return "%d" % self._val['atom']['ival']

  def children(self):
    if long(self._val) == 0:
      return []
    elif long(self._val['type']) == 0:
      return [
        ('atom', self._val['atom'])
      ]
    else:
      return [
        ('car' ,  self._val["slots"][0]),
        ('cdr' ,  self._val["slots"][1]),
      ]

def cons_pp_lookup(val):
  if str(val.type) == 'struct cons *':
    return cons_pp(val)
  else:
    return None

del gdb.pretty_printers[1:]
gdb.pretty_printers.append(cons_pp_lookup)
