Source Code for Module osh.command.unique

  1  # osh 
  2  # Copyright (C) Jack Orenstein <jao@geophile.com> 
  3  # 
  4  # This program is free software; you can redistribute it and/or modify 
  5  # it under the terms of the GNU General Public License as published by 
  6  # the Free Software Foundation; either version 2 of the License, or 
  7  # (at your option) any later version. 
  8  # 
  9  # This program is distributed in the hope that it will be useful, 
 10  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
 11  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 12  # GNU General Public License for more details. 
 13  # 
 14  # You should have received a copy of the GNU General Public License 
 15  # along with this program; if not, write to the Free Software 
 16  # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
 17   
 18  """C{unique [-c]} 
 19   
 20  Input objects are passed to output, removing duplicates. No output is 
 21  generated until the end of the input stream occurs. However, if the 
 22  duplicates are known to be consecutive, then specifying C{-c} allows 
 23  output to be generated sooner. Input order is preserved only if C{-c} 
 24  is specified. 
 25   
 26  """ 
 27   
 28  import types 
 29   
 30  import osh.args 
 31  import osh.core 
 32   
 33  Option = osh.args.Option 
 34   
 35  # CLI 
 36 -def _unique(): 
 37      return _Unique() 
 38   
 39  # API 
 40 -def unique(consecutive = False): 
 41      """Input objects are passed to output, removing duplicates. No output 
 42      is generated until the end of the input stream occurs. However, if the 
 43      duplicates are known to be consecutive, then setting C{consecutive} to true 
 44      allows output to be generated sooner. Input order is preserved only if 
 45      C{consecutive} is true. 
 46      """ 
 47      args = [] 
 48      if consecutive: 
 49          args.append(Option('-c')) 
 50      return _Unique().process_args(*args) 
 51   
 52 -class _Unique(osh.core.Op): 
 53   
 54      _uniquer = None 
 55   
 56   
 57      # object interface 
 58   
 59 -    def __init__(self): 
 60          osh.core.Op.__init__(self, 'c', (0, 0)) 
 61   
 62   
 63      # BaseOp interface 
 64   
 65 -    def doc(self): 
 66          return __doc__ 
 67   
 68 -    def setup(self): 
 69          args = self.args() 
 70          if args.has_next(): 
 71              self.usage() 
 72          if args.flag('-c'): 
 73              self._uniquer = _ConsecutiveUniquer(self) 
 74          else: 
 75              self._uniquer = _GeneralUniquer(self) 
 76   
 77 -    def receive(self, object): 
 78          self._uniquer.receive(object) 
 79   
 80 -    def receive_complete(self): 
 81          self._uniquer.receive_complete() 
 82   
 83   
 84 -class _GeneralUniquer(object): 
 85   
 86      _command = None 
 87      _unique = None 
 88   
 89 -    def __init__(self, command): 
 90          self._command = command 
 91          self._unique = {} 
 92   
 93 -    def receive(self, object): 
 94          if type(object) == types.ListType: 
 95              object = tuple(object) 
 96          self._unique[object] = None 
 97   
 98 -    def receive_complete(self): 
 99          for key in self._unique.keys(): 
100              self._command.send(key) 
101          self._command.send_complete() 
102   
103 -class _ConsecutiveUniquer(object): 
104   
105      _command = None 
106      _current = None 
107   
108 -    def __init__(self, command): 
109          self._command = command 
110   
111 -    def receive(self, object): 
112          if self._current != object: 
113              if self._current is not None: 
114                  self._command.send(self._current) 
115              self._current = object 
116   
117 -    def receive_complete(self): 
118          if self._current is not None: 
119              self._command.send(self._current) 
120          self._command.send_complete() 
121