uindex 0.1.1

Universal index
Documentation 
// Copyright (c) 2020 by Enrique Pérez Arnaud <enrique at cazalla.net>
//
// This file is part of the modus_ponens project.
// http://www.modus_ponens.net
//
// The modus_ponens project is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The modus_ponens project is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with any part of the modus_ponens project.
// If not, see <http://www.gnu.org/licenses/>.

use std::collections::HashMap;

use crate::segment::MPSegment;

pub type MPMatching<'a> = HashMap<&'a MPSegment, &'a MPSegment>;

pub fn get_or_key<'a>(matching: &'a MPMatching, key: &'a MPSegment) -> &'a MPSegment {
    match matching.get(key) {
        Some(matched) => *matched,
        None => key,
    }
}