"""
Provides useful functions and classes. Most useful are probably
printTreeDocs and printTreeSpec.
:copyright: Copyright 2006-2009 by Oliver Schoenborn, all rights reserved.
:license: BSD, see LICENSE.txt for details.
"""
__all__ = ('StructMsg', 'Callback', 'Enum' )
class StructMsg:
'''
This *can* be used to package message data. Each of the keyword
args given at construction will be stored as a member of the 'data'
member of instance. E.g. "m=Message2(a=1, b='b')" would succeed
"assert m.data.a==1" and "assert m.data.b=='b'". However, use of
Message2 makes your messaging code less documented and harder to
debug.
'''
def __init__(self, **kwargs):
class Data: pass
self.data = Data()
self.data.__dict__.update(kwargs)
class Callback:
'''This can be used to wrap functions that are referenced by class
data if the data should be called as a function. E.g. given
>>> def func(): pass
>>> class A:
....def __init__(self): self.a = func
then doing
>>> boo=A(); boo.a()
will fail since Python will try to call a() as a method of boo,
whereas a() is a free function. But if you have instead
"self.a = Callback(func)", then "boo.a()" works as expected.
'''
def __init__(self, callable_):
self.__callable = callable_
def __call__(self, *args, **kwargs):
return self.__callable(*args, **kwargs)
class Enum:
'''Used only internally. Represent one value out of an enumeration
set. It is meant to be used as::
class YourAllowedValues:
enum1 = Enum()
# or:
enum2 = Enum(value)
# or:
enum3 = Enum(value, 'descriptionLine1')
# or:
enum3 = Enum(None, 'descriptionLine1', 'descriptionLine2', ...)
val = YourAllowedValues.enum1
...
if val is YourAllowedValues.enum1:
...
'''
nextValue = 0
values = set()
def __init__(self, value=None, *desc):
'''Use value if given, otherwise use next integer.'''
self.desc = '\n'.join(desc)
if value is None:
assert Enum.nextValue not in Enum.values
self.value = Enum.nextValue
Enum.values.add(self.value)
Enum.nextValue += 1
# check that we haven't run out of integers!
if Enum.nextValue == 0:
raise RuntimeError('Ran out of enumeration values?')
else:
try:
value + Enum.nextValue
raise ValueError('Not allowed to assign integer to enumerations')
except TypeError:
pass
self.value = value
if self.value not in Enum.values:
Enum.values.add(self.value)
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