'Reinterpret the failing statement and returns a detailed information
about what operations are performed.'

def reinterpret(self):

    if (self.exprinfo is None):
        source = str(self.statement).strip()
        x = py.code._reinterpret(source, self.frame, should_fail=True)
        if (not isinstance(x, str)):
            raise TypeError(('interpret    returned    non-string    %r' % (x,)))
        self.exprinfo = x
    return self.exprinfo
