Source Code for Module osh.command.f

 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{f FUNCTION} 
19   
20  The result obtained by applying C{FUNCTION} to an input sequence is 
21  written as output. 
22   
23  B{Example}: If input contains the sequences C{(1, 2), (3, 4), (5, 6)} 
24  then this command:: 
25   
26      f 'x, y: x + y' 
27   
28  generates the output C{(3,), (7,), (11,)}. 
29  """ 
30   
31  import types 
32   
33  import osh.function 
34  import osh.core 
35   
36  # CLI 
37 -def _f(): 
38      return _F() 
39   
40  # API 
41 -def f(function): 
42      """The result obtained by applying C{FUNCTION} to an input sequence is 
43      written as output. 
44      """ 
45      return _F().process_args(function) 
46   
47  # f can be used as a generator (function with no args) or 
48  # downstream. That's why receive and execute are both defined. 
49   
50 -class _F(osh.core.Generator): 
51   
52      _function = None 
53   
54   
55      # object interface 
56   
57 -    def __init__(self): 
58          osh.core.Generator.__init__(self, '', (1, 1)) 
59   
60   
61      # BaseOp interface 
62       
63 -    def doc(self): 
64          return __doc__ 
65   
66 -    def setup(self): 
67          args = self.args() 
68          self._function = args.next_function() 
69          if self._function is None or args.has_next(): 
70              self.usage() 
71   
72 -    def receive(self, object): 
73          # core ensures that we get a tuple (see wrap_if_necessary) 
74          self.send(self._function(*object)) 
75   
76   
77      # Generator interface 
78   
79 -    def execute(self): 
80          self.send(self._function()) 
81