forked from VimPlug/jedi
68 lines
2.0 KiB
Python
68 lines
2.0 KiB
Python
from jedi.parser.representation import Flow
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class Status(object):
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lookup_table = {}
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def __init__(self, value, name):
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self._value = value
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self._name = name
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Status.lookup_table[value] = self
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def invert(self):
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if self is REACHABLE:
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return UNREACHABLE
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elif self is UNREACHABLE:
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return REACHABLE
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else:
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return UNSURE
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def __and__(self, other):
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if UNSURE in (self, other):
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return UNSURE
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else:
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return REACHABLE if self._value and other._value else UNREACHABLE
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def __repr__(self):
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return '<%s: %s>' % (type(self).__name__, self._name)
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REACHABLE = Status(True, 'reachable')
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UNREACHABLE = Status(False, 'unreachable')
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UNSURE = Status(None, 'unsure')
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def break_check(evaluator, base_scope, element_scope):
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reachable = REACHABLE
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if isinstance(element_scope, Flow):
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if element_scope.command == 'else':
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check_scope = element_scope
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while check_scope.previous is not None:
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check_scope = check_scope.previous
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reachable = _check_flow(evaluator, check_scope)
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if reachable in (REACHABLE, UNSURE):
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break
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reachable = reachable.invert()
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else:
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reachable = _check_flow(evaluator, element_scope)
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# Only reachable branches need to be examined further.
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if reachable in (UNREACHABLE, UNSURE):
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return reachable
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if base_scope != element_scope and base_scope != element_scope.parent:
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return reachable & break_check(evaluator, base_scope, element_scope.parent)
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return reachable
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def _check_flow(evaluator, flow):
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if flow.command in ('elif', 'if') and flow.inputs:
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types = evaluator.eval_statement(flow.inputs[0])
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values = set(x.py__bool__() for x in types)
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if len(values) == 1:
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return Status.lookup_table[values.pop()]
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else:
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return UNSURE
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elif flow.command in ('try', 'except', 'finally', 'while'):
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return UNSURE
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