| 1 | """Provides a variety of classes to create pseudo keywords and pseudo files.""" |
| 2 | |
| 3 | __author__ = "Patrick K. O'Brien <pobrien@orbtech.com>" |
| 4 | __cvsid__ = "$Id$" |
| 5 | __revision__ = "$Revision$"[11:-2] |
| 6 | |
| 7 | |
| 8 | class PseudoKeyword: |
| 9 | """A callable class that calls a method passed as a parameter. |
| 10 | |
| 11 | Good for creating a pseudo keyword in the python runtime |
| 12 | environment. The keyword is really an object that has a repr() |
| 13 | that calls itself which calls the method that was passed in the |
| 14 | init of the object. All this just to avoid having to type in the |
| 15 | closing parens on a method. So, for example: |
| 16 | |
| 17 | >>> quit = PseudoKeyword(SomeObject.someMethod) |
| 18 | >>> quit |
| 19 | |
| 20 | SomeObject.someMethod gets executed as if it had been called |
| 21 | directly and the user didn't have to type the parens, like |
| 22 | 'quit()'. This technique is most applicable for pseudo keywords |
| 23 | like quit, exit and help. |
| 24 | |
| 25 | If SomeObject.someMethod can take parameters, they can still be |
| 26 | passed by using the keyword in the traditional way with parens.""" |
| 27 | |
| 28 | def __init__(self, method): |
| 29 | """Create a callable object that executes method when called.""" |
| 30 | |
| 31 | if callable(method): |
| 32 | self.method = method |
| 33 | else: |
| 34 | raise ValueError, 'method must be callable' |
| 35 | |
| 36 | def __call__(self, *args, **kwds): |
| 37 | self.method(*args, **kwds) |
| 38 | |
| 39 | def __repr__(self): |
| 40 | self() |
| 41 | return '' |
| 42 | |
| 43 | |
| 44 | class PseudoFile: |
| 45 | |
| 46 | def __init__(self): |
| 47 | """Create a file-like object.""" |
| 48 | pass |
| 49 | |
| 50 | def readline(self): |
| 51 | pass |
| 52 | |
| 53 | def write(self, s): |
| 54 | pass |
| 55 | |
| 56 | def writelines(self, l): |
| 57 | map(self.write, l) |
| 58 | |
| 59 | def flush(self): |
| 60 | pass |
| 61 | |
| 62 | def isatty(self): |
| 63 | pass |
| 64 | |
| 65 | |
| 66 | class PseudoFileIn(PseudoFile): |
| 67 | |
| 68 | def __init__(self, readline, readlines=None): |
| 69 | if callable(readline): |
| 70 | self.readline = readline |
| 71 | else: |
| 72 | raise ValueError, 'readline must be callable' |
| 73 | if callable(readlines): |
| 74 | self.readlines = readlines |
| 75 | |
| 76 | def isatty(self): |
| 77 | return 1 |
| 78 | |
| 79 | |
| 80 | class PseudoFileOut(PseudoFile): |
| 81 | |
| 82 | def __init__(self, write): |
| 83 | if callable(write): |
| 84 | self.write = write |
| 85 | else: |
| 86 | raise ValueError, 'write must be callable' |
| 87 | |
| 88 | def isatty(self): |
| 89 | return 1 |
| 90 | |
| 91 | |
| 92 | class PseudoFileErr(PseudoFile): |
| 93 | |
| 94 | def __init__(self, write): |
| 95 | if callable(write): |
| 96 | self.write = write |
| 97 | else: |
| 98 | raise ValueError, 'write must be callable' |
| 99 | |
| 100 | def isatty(self): |
| 101 | return 1 |