Source Code for Module osh.command.sort

 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{sort [FUNCTION]} 
19   
20  Input objects are sorted before being written to output.  If 
21  C{FUNCTION} is not provided then input objects are sorted using the 
22  default ordering (i.e., based on the C{cmp} function). 
23   
24  If C{FUNCTION} is provided, then sorting is done by applying C{cmp} to 
25  values obtained by applying C{FUNCTION} to the input objects. 
26  """ 
27   
28  import osh.core 
29   
30  # CLI 
31 -def _sort(): 
32      return _Sort() 
33   
34  # CLI 
35 -def sort(function = None): 
36      """Input objects are sorted before being written to output. If 
37      C{function} is not provided then input objects are sorted using the 
38      default ordering (i.e., based on the C{cmp} function). 
39      If C{function} is provided, then sorting is done by applying C{cmp} to 
40      values obtained by applying C{function} to the input objects. 
41      """ 
42      args = [] 
43      if function: 
44          args.append(function) 
45      return _Sort().process_args(*args) 
46   
47 -class _Sort(osh.core.Op): 
48   
49      _key = None 
50      _list = None 
51   
52   
53      # object interface 
54   
55 -    def __init__(self): 
56          osh.core.Op.__init__(self, '', (0, 1)) 
57   
58   
59      # BaseOp interface 
60       
61 -    def doc(self): 
62          return __doc__ 
63   
64 -    def setup(self): 
65          args = self.args() 
66          if args.has_next(): 
67              self._key = args.next_function() 
68          if args.has_next(): 
69              self.usage() 
70          self._list = [] 
71       
72 -    def receive(self, object): 
73          self._list.append(object) 
74       
75 -    def receive_complete(self): 
76          key = self._key 
77          if key: 
78              # Attach the keys, sort by the key, then detach the key. 
79              self._list = [(key(*object), object) for object in self._list] 
80              self._list.sort(lambda x, y: cmp(x[0], y[0])) 
81              self._list = [t[1] for t in self._list] 
82          else: 
83              self._list.sort() 
84          for object in self._list: 
85              self.send(object) 
86          self.send_complete() 
87