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Walk a tree of generators without yielding things recursively. Check out the docstring. It has an example ;)

Python, 88 lines
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88``` ```import types __docformat__ = "restructuredtext" def walk_recursive_generators(generator): """Walk a tree of generators without yielding things recursively. Let's suppose you have this: >>> def generator0(): ... yield 3 ... yield 4 ... >>> def generator1(): ... yield 2 ... for i in generator0(): ... yield i ... yield 5 ... >>> def generator2(): ... yield 1 ... for i in generator1(): ... yield i ... yield 6 ... >>> for i in generator2(): ... print i ... 1 2 3 4 5 6 Notice the way the generators are recursively yielding values. This library uses a technique called "bounce" that is usually used to implement stackless interpreters. It lets you write: >>> def generator0(): ... yield 3 ... yield 4 ... >>> def generator1(): ... yield 2 ... yield generator0() ... yield 5 ... >>> def generator2(): ... yield 1 ... yield generator1() ... yield 6 ... >>> for i in walk_recursive_generators(generator2()): ... print i ... 1 2 3 4 5 6 Look Ma! No recursive yields! """ stack = [generator] while stack: for x in stack[-1]: if isinstance(x, types.GeneratorType): stack.append(x) # Recurse. break else: yield x else: stack.pop() def _test(): import doctest doctest.testmod() if __name__ == "__main__": _test() ```
 Created by Shannon -jj Behrens on Wed, 28 Nov 2007 (PSF)