##// END OF EJS Templates
Avoid Python 2.5 warning...
Alexis S. L. Carvalho -
r2960:61afc32c default
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@@ -1,135 +1,135 b''
1 '''Demand load modules when used, not when imported.'''
1 '''Demand load modules when used, not when imported.'''
2
2
3 __author__ = '''Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>.
3 __author__ = '''Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>.
4 This software may be used and distributed according to the terms
4 This software may be used and distributed according to the terms
5 of the GNU General Public License, incorporated herein by reference.'''
5 of the GNU General Public License, incorporated herein by reference.'''
6
6
7 # this is based on matt's original demandload module. it is a
7 # this is based on matt's original demandload module. it is a
8 # complete rewrite. some time, we may need to support syntax of
8 # complete rewrite. some time, we may need to support syntax of
9 # "import foo as bar".
9 # "import foo as bar".
10
10
11 class _importer(object):
11 class _importer(object):
12 '''import a module. it is not imported until needed, and is
12 '''import a module. it is not imported until needed, and is
13 imported at most once per scope.'''
13 imported at most once per scope.'''
14
14
15 def __init__(self, scope, modname, fromlist):
15 def __init__(self, scope, modname, fromlist):
16 '''scope is context (globals() or locals()) in which import
16 '''scope is context (globals() or locals()) in which import
17 should be made. modname is name of module to import.
17 should be made. modname is name of module to import.
18 fromlist is list of modules for "from foo import ..."
18 fromlist is list of modules for "from foo import ..."
19 emulation.'''
19 emulation.'''
20
20
21 self.scope = scope
21 self.scope = scope
22 self.modname = modname
22 self.modname = modname
23 self.fromlist = fromlist
23 self.fromlist = fromlist
24 self.mod = None
24 self.mod = None
25
25
26 def module(self):
26 def module(self):
27 '''import the module if needed, and return.'''
27 '''import the module if needed, and return.'''
28 if self.mod is None:
28 if self.mod is None:
29 self.mod = __import__(self.modname, self.scope, self.scope,
29 self.mod = __import__(self.modname, self.scope, self.scope,
30 self.fromlist)
30 self.fromlist)
31 del self.modname, self.fromlist
31 del self.modname, self.fromlist
32 return self.mod
32 return self.mod
33
33
34 class _replacer(object):
34 class _replacer(object):
35 '''placeholder for a demand loaded module. demandload puts this in
35 '''placeholder for a demand loaded module. demandload puts this in
36 a target scope. when an attribute of this object is looked up,
36 a target scope. when an attribute of this object is looked up,
37 this object is replaced in the target scope with the actual
37 this object is replaced in the target scope with the actual
38 module.
38 module.
39
39
40 we use __getattribute__ to avoid namespace clashes between
40 we use __getattribute__ to avoid namespace clashes between
41 placeholder object and real module.'''
41 placeholder object and real module.'''
42
42
43 def __init__(self, importer, target):
43 def __init__(self, importer, target):
44 self.importer = importer
44 self.importer = importer
45 self.target = target
45 self.target = target
46 # consider case where we do this:
46 # consider case where we do this:
47 # demandload(globals(), 'foo.bar foo.quux')
47 # demandload(globals(), 'foo.bar foo.quux')
48 # foo will already exist in target scope when we get to
48 # foo will already exist in target scope when we get to
49 # foo.quux. so we remember that we will need to demandload
49 # foo.quux. so we remember that we will need to demandload
50 # quux into foo's scope when we really load it.
50 # quux into foo's scope when we really load it.
51 self.later = []
51 self.later = []
52
52
53 def module(self):
53 def module(self):
54 return object.__getattribute__(self, 'importer').module()
54 return object.__getattribute__(self, 'importer').module()
55
55
56 def __getattribute__(self, key):
56 def __getattribute__(self, key):
57 '''look up an attribute in a module and return it. replace the
57 '''look up an attribute in a module and return it. replace the
58 name of the module in the caller\'s dict with the actual
58 name of the module in the caller\'s dict with the actual
59 module.'''
59 module.'''
60
60
61 module = object.__getattribute__(self, 'module')()
61 module = object.__getattribute__(self, 'module')()
62 target = object.__getattribute__(self, 'target')
62 target = object.__getattribute__(self, 'target')
63 importer = object.__getattribute__(self, 'importer')
63 importer = object.__getattribute__(self, 'importer')
64 later = object.__getattribute__(self, 'later')
64 later = object.__getattribute__(self, 'later')
65
65
66 if later:
66 if later:
67 demandload(module.__dict__, ' '.join(later))
67 demandload(module.__dict__, ' '.join(later))
68
68
69 importer.scope[target] = module
69 importer.scope[target] = module
70
70
71 return getattr(module, key)
71 return getattr(module, key)
72
72
73 class _replacer_from(_replacer):
73 class _replacer_from(_replacer):
74 '''placeholder for a demand loaded module. used for "from foo
74 '''placeholder for a demand loaded module. used for "from foo
75 import ..." emulation. semantics of this are different than
75 import ..." emulation. semantics of this are different than
76 regular import, so different implementation needed.'''
76 regular import, so different implementation needed.'''
77
77
78 def module(self):
78 def module(self):
79 importer = object.__getattribute__(self, 'importer')
79 importer = object.__getattribute__(self, 'importer')
80 target = object.__getattribute__(self, 'target')
80 target = object.__getattribute__(self, 'target')
81
81
82 return getattr(importer.module(), target)
82 return getattr(importer.module(), target)
83
83
84 def __call__(self, *args, **kwargs):
84 def __call__(self, *args, **kwargs):
85 target = object.__getattribute__(self, 'module')()
85 target = object.__getattribute__(self, 'module')()
86 return target(*args, **kwargs)
86 return target(*args, **kwargs)
87
87
88 def demandload(scope, modules):
88 def demandload(scope, modules):
89 '''import modules into scope when each is first used.
89 '''import modules into scope when each is first used.
90
90
91 scope should be the value of globals() in the module calling this
91 scope should be the value of globals() in the module calling this
92 function, or locals() in the calling function.
92 function, or locals() in the calling function.
93
93
94 modules is a string listing module names, separated by white
94 modules is a string listing module names, separated by white
95 space. names are handled like this:
95 space. names are handled like this:
96
96
97 foo import foo
97 foo import foo
98 foo bar import foo, bar
98 foo bar import foo, bar
99 foo@bar import foo as bar
99 foo@bar import foo as bar
100 foo.bar import foo.bar
100 foo.bar import foo.bar
101 foo:bar from foo import bar
101 foo:bar from foo import bar
102 foo:bar,quux from foo import bar, quux
102 foo:bar,quux from foo import bar, quux
103 foo.bar:quux from foo.bar import quux'''
103 foo.bar:quux from foo.bar import quux'''
104
104
105 for mod in modules.split():
105 for mod in modules.split():
106 col = mod.find(':')
106 col = mod.find(':')
107 if col >= 0:
107 if col >= 0:
108 fromlist = mod[col+1:].split(',')
108 fromlist = mod[col+1:].split(',')
109 mod = mod[:col]
109 mod = mod[:col]
110 else:
110 else:
111 fromlist = []
111 fromlist = []
112 as = None
112 as_ = None
113 if '@' in mod:
113 if '@' in mod:
114 mod, as = mod.split("@")
114 mod, as_ = mod.split("@")
115 importer = _importer(scope, mod, fromlist)
115 importer = _importer(scope, mod, fromlist)
116 if fromlist:
116 if fromlist:
117 for name in fromlist:
117 for name in fromlist:
118 scope[name] = _replacer_from(importer, name)
118 scope[name] = _replacer_from(importer, name)
119 else:
119 else:
120 dot = mod.find('.')
120 dot = mod.find('.')
121 if dot >= 0:
121 if dot >= 0:
122 basemod = mod[:dot]
122 basemod = mod[:dot]
123 val = scope.get(basemod)
123 val = scope.get(basemod)
124 # if base module has already been demandload()ed,
124 # if base module has already been demandload()ed,
125 # remember to load this submodule into its namespace
125 # remember to load this submodule into its namespace
126 # when needed.
126 # when needed.
127 if isinstance(val, _replacer):
127 if isinstance(val, _replacer):
128 later = object.__getattribute__(val, 'later')
128 later = object.__getattribute__(val, 'later')
129 later.append(mod[dot+1:])
129 later.append(mod[dot+1:])
130 continue
130 continue
131 else:
131 else:
132 basemod = mod
132 basemod = mod
133 if not as:
133 if not as_:
134 as = basemod
134 as_ = basemod
135 scope[as] = _replacer(importer, as)
135 scope[as_] = _replacer(importer, as_)
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