Class AndExpectation

tests/timeline.py:657–687

class AndExpectation(DerivativeExpectation):
    OPERATOR = "&"

    def test(self, first, last):
        assert isinstance(first, Occurrence)
        assert isinstance(last, Occurrence)

        if len(self.expectations) <= 1:
            for exp in self.expectations:
                for reasons in exp.test(first, last):
                    yield reasons
            return

        lhs = self.expectations[0]
        rhs = AndExpectation(*self.expectations[1:])
        for lhs_reasons in lhs.test(first, last):
            for rhs_reasons in rhs.test(first, last):
                reasons = lhs_reasons.copy()
                reasons.update(rhs_reasons)
                yield reasons

    @property
    def has_lower_bound(self):
        return any(exp.has_lower_bound for exp in self.expectations)

    def __and__(self, other):
        assert isinstance(other, Expectation)
        return AndExpectation(*(self.expectations + (other,)))

    def __repr__(self):
        return "(" + " & ".join(repr(exp) for exp in self.expectations) + ")"


class XorExpectation(DerivativeExpectation):