//  Library for the Zia programming language.
// Copyright (C) 2020 Charles Johnson
//
// This program 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.
//
// This program 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 this program. If not, see <http://www.gnu.org/licenses/>.

#[macro_use]
extern crate proptest;
extern crate zia;
#[macro_use]
extern crate test_zia;

use test_zia::CONCRETE_SYMBOLS;
use zia::NEW_CONTEXT;

#[test]
fn lower_than_default_precedence() {
    let mut context = NEW_CONTEXT.clone();
    assert_eq!(context.execute("let default > prec b"), "");
    assert_eq!(context.execute("prec b"), "prec b");
    assert_eq!(context.execute("c d b"), "(c d) b");
}

#[test]
fn set_let_precedence() {
    let mut context = NEW_CONTEXT.clone();
    assert_eq!(context.execute("let default > prec let"), "");
    assert_eq!(context.execute("let a -> b"), "");
    assert_eq!(context.execute("a"), "b");
}
#[test]
fn set_reduction_precedence() {
    let mut context = NEW_CONTEXT.clone();
    assert_eq!(context.execute("let default > prec ->"), "");
    assert_eq!(context.execute("let (prec ->) > prec let"), "");
    // Cannot yet infer partial order. Requires implication to express transitive property
    assert_eq!(context.execute("let default > prec let"), "");
    assert_eq!(context.execute("let c d -> e"), "");
    assert_eq!(context.execute("c d"), "e");
}

proptest! {
    #[test]
    fn default_precedence(a in "\\PC*") {
        assume_abstract!(a);
        assume_symbol!(a);
        let mut context = NEW_CONTEXT.clone();
        assert_eq!(context.execute(&format!("prec {}", a)), "default");
    }
}