1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
#![deny(clippy::pedantic)]
#![deny(clippy::all)]
//! Tests if multiple generic parameters work, if the return value's lifetime depends on the mapping function lifetime.
use std::rc::Rc;
use higher_free_macro::free;
use higher::{Functor, Bind, Apply};
#[derive(Clone)]
struct TestFunctor<'a, 'b, A, B>{
data : &'b B,
next : Rc<dyn Fn(i32)->A + 'a>,
}
impl<'a,'b,A : 'a,B> Functor<'a,A> for TestFunctor<'a, 'b, A, B>{
type Target<T> = TestFunctor<'a, 'b, T, B>;
fn fmap<C, F>(self, f: F) -> Self::Target<C>
where
F: Fn(A) -> C + 'a {
TestFunctor{ data : self.data, next : Rc::new(move |x| f((self.next)(x)))}
}
}
free!(<'xx>, FreeTest<'xx,'yy,AA,BB>, TestFunctor<'xx, 'yy, FreeTest<'xx, 'yy, AA, BB>, BB>);
#[test]
fn test_lifetime_multiple_generics(){
let free_monad = FreeTest::lift_f(TestFunctor{ data : &"Listening to NSP while writing this.", next : Rc::new(|x| f64::from(x)*0.5f64)});
let functions = FreeTest::Pure(|x : f64| -> bool {x > 0.7f64} ).fmap(Into::into);
let free_monad_after_apply = free_monad.apply(functions);
match free_monad_after_apply {
FreeTest::Free(m) => {
assert_eq!(m.data, &"Listening to NSP while writing this.");
let x = m.next.clone();
let y = m.next.clone();
let m1 = x(1);
match m1{
FreeTest::Pure(v) => assert!(!v),
FreeTest::Free(_) => unreachable!(),
}
let m2 = y(3);
match m2{
FreeTest::Pure(v) => assert!(v),
FreeTest::Free(_) => unreachable!(),
}
},
FreeTest::Pure(_) => unreachable!()
}
}
//just to appease clippy without disabling the lint....
macro_rules! assert_nearly_equal {
($a:expr, $b:expr, $c:expr) => {
assert!((($a)-($b)).abs() < $c)
};
}
#[test]
fn test_lifetime_multiple_generics_bind(){
let m = FreeTest::lift_f(TestFunctor{ data : &"Listening to Soilwork while writing this.", next : Rc::new(|x| f64::from(x)*0.5f64)});
let m = m.bind(|x : f64| -> FreeTest<_,_> {
if x < 0.0 {
FreeTest::Pure(x.abs().floor())
} else {
FreeTest::lift_f(TestFunctor{data : &"Now it's Little Big.", next : Rc::new(move |y| f64::from(y) + x.ceil())})
}});
match m{
FreeTest::Free(m) => {
assert_eq!(m.data, &"Listening to Soilwork while writing this.");
match (m.next)(-3){
FreeTest::Pure(v) => assert_nearly_equal!(v, 1f64, f64::EPSILON),
FreeTest::Free(_) => unreachable!(),
}
match (m.next)(3){
FreeTest::Pure(_) => unreachable!(),
FreeTest::Free(v) => {
assert_eq!(v.data, &"Now it's Little Big.");
match (v.next)(5) {
FreeTest::Pure(v) => assert_nearly_equal!(v, 7f64, f64::EPSILON),
FreeTest::Free(_) => unreachable!(),
}
},
}
},
FreeTest::Pure(_) => unreachable!()
}
}
|
