python/clippy/__init__.py

   1 # FRR CLI preprocessor
   2 #
   3 # Copyright (C) 2017  David Lamparter for NetDEF, Inc.
   4 #
   5 # This program is free software; you can redistribute it and/or modify it
   6 # under the terms of the GNU General Public License as published by the Free
   7 # Software Foundation; either version 2 of the License, or (at your option)
   8 # any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful, but WITHOUT
  11 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13 # more details.
  14 #
  15 # You should have received a copy of the GNU General Public License along
  16 # with this program; see the file COPYING; if not, write to the Free Software
  17 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18
  19 import _clippy
  20 from _clippy import parse, Graph, GraphNode
  21
  22 def graph_iterate(graph):
  23     '''iterator yielding all nodes of a graph
  24
  25     nodes arrive in input/definition order, graph circles are avoided.
  26     '''
  27
  28     queue = [(graph.first(), frozenset(), 0)]
  29     while len(queue) > 0:
  30         node, stop, depth = queue.pop(0)
  31         yield node, depth
  32
  33         join = node.join()
  34         if join is not None:
  35             queue.insert(0, (join, stop.union(frozenset([node])), depth))
  36             join = frozenset([join])
  37
  38         stop = join or stop
  39         nnext = node.next()
  40         for n in reversed(nnext):
  41             if n not in stop and n is not node:
  42                 queue.insert(0, (n, stop, depth + 1))
  43
  44 def dump(graph):
  45     '''print out clippy.Graph'''
  46
  47     for i, depth in graph_iterate(graph):
  48         print('\t%s%s %r' % ('  ' * (depth * 2), i.type, i.text))
  49
  50 def wrdiff(filename, buf):
  51     '''write buffer to file if contents changed'''
  52
  53     expl = ''
  54     if hasattr(buf, 'getvalue'):
  55         buf = buf.getvalue()
  56     old = None
  57     try:    old = open(filename, 'r').read()
  58     except: pass
  59     if old == buf:
  60         # sys.stderr.write('%s unchanged, not written\n' % (filename))
  61         return
  62     with open('.new.' + filename, 'w') as out:
  63         out.write(buf)
  64     os.rename('.new.' + filename, filename)