make sure apply() only hits each pattern one
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52adb582dc
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@ -98,16 +98,30 @@ class Pattern:
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func: Callable[['Pattern'], 'Pattern']
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func: Callable[['Pattern'], 'Pattern']
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) -> 'Pattern':
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) -> 'Pattern':
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"""
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"""
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Recursively apply func() to this pattern and its subpatterns.
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Recursively apply func() to this pattern and any pattern it references.
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func() is expected to take and return a Pattern.
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func() is expected to take and return a Pattern.
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func() is first applied to the pattern as a whole, then the subpatterns.
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func() is first applied to the pattern as a whole, then the referenced patterns.
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It is only applied to any given pattern once, regardless of how many times it is
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referenced.
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:param func: Function which accepts a Pattern, and returns a pattern.
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:param func: Function which accepts a Pattern, and returns a pattern.
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:return: The result of applying func() to this pattern and all subpatterns.
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:return: The result of applying func() to this pattern and all subpatterns.
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:raises: PatternError if called on a pattern containing a circular reference.
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"""
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"""
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pat_map = {id(self): None}
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pat = func(self)
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pat = func(self)
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pat_map[id(self)] = pat
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for subpat in pat.subpatterns:
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for subpat in pat.subpatterns:
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subpat.pattern = subpat.pattern.apply(func)
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ref_pat_id = id(subpat.pattern)
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if ref_pat_id not in pat_map:
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pat_map[ref_pat_id] = None
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subpat.pattern = subpat.pattern.apply(func)
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pat_map[ref_pat_id] = subpat.pattern
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elif pat_map[ref_pat_id] is None:
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raise PatternError('.apply() called on pattern with circular reference')
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else:
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subpat.pattern = pat_map[ref_pat_id]
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return pat
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return pat
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def polygonize(self,
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def polygonize(self,
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