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// Copyright 2018 Pierre Talbot (IRCAM) // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your // option. This file may not be copied, modified, or distributed // except according to those terms. /// A [lattice](https://en.wikipedia.org/wiki/Lattice_(order)) is an ordered set where every element can be combined with a `join` and `meet` operations. /// However, the following family of traits do not represent the full lattice, but an element of this lattice. /// This is the reason why we do not require `Lattice` to inherit from `Collection`. use trilean::SKleene; pub trait Join<RHS: ?Sized = Self> { fn join(self, other: RHS) -> Self; fn join_in_place(&mut self, other: RHS); } pub trait Meet<RHS: ?Sized = Self> { fn meet(self, other: RHS) -> Self; fn meet_in_place(&mut self, other: RHS); } pub trait Entailment<RHS: ?Sized = Self> { fn entail(&self, other: &RHS) -> SKleene; } pub trait Lattice: Join + Meet + Entailment {} impl<R> Lattice for R where R: Join, R: Meet, R: Entailment {}