match: strengthen visit_children_set invariant, Recursive means "all files" My previous interpretation of "Recursive" was too relaxed: I thought it instructed the caller to do something like this: > you can stop calling `visit_children_set` because you'll need to descend into > every directory recursively, but you should still check every file if it > matches or not Whereas the real instruction seems to be: > I guarantee that everything in this subtree matches, you can stop > querying the matcher for all files and dirs altogether. The evidence to support this: - the test actually passes with the stronger invariant, revealing no exceptions from this rule - the implementation of `visit_children_set` for `DifferenceMatcher` clearly relies on this requirement, so it must hold for that not to lead to bugs.

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#!/usr/bin/env python3

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#

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# A portable replacement for 'seq'

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#

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# Usage:

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#   seq STOP              [1, STOP] stepping by 1

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#   seq START STOP        [START, STOP] stepping by 1

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#   seq START STEP STOP   [START, STOP] stepping by STEP

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import os

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import sys

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try:

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    import msvcrt

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    msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)

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    msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)

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    msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)

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except ImportError:

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    pass

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start = 1

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if len(sys.argv) > 2:

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    start = int(sys.argv[1])

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step = 1

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if len(sys.argv) > 3:

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    step = int(sys.argv[2])

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stop = int(sys.argv[-1]) + 1

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for i in range(start, stop, step):

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    print(i)