rufi_gradient 2.0.12

A simple aggregate program implementing the gradient with the RuFi framework
Documentation 
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

use rf_core::lang::builtins::{foldhood_plus, mux};
use rf_core::lang::{nbr, rep};
use rf_core::sensor_id::sensor;
use rf_core::vm::round_vm::RoundVM;

/// Compute the gradient of a source.
/// N.B. The source must be present in the local [Context] by setting the "source" [Sensor] to true.
/// # Arguments:
/// * `vm` - The RoundVM to compute the gradient on.
/// # Returns:
/// * `(RoundVM, f64)` - A tuple with the RoundVM after the gradient has been computed and the distance from the source.
pub fn gradient(vm: &mut RoundVM) -> f64 {
    fn is_source(vm: &mut RoundVM) -> bool {
        vm.local_sense::<bool>(&sensor("source")).unwrap().clone()
    }

    rep(
        vm,
        |_| 0.0,
        |vm1, d| {
            mux(vm1, is_source, |_vm| 0.0, |vm2| {
                foldhood_plus(
                    vm2,
                    |_vm| f64::INFINITY,
                    |a, b| a.min(b),
                    |vm3| {
                        nbr(vm3, |_vm| d) + 1.0
                    },
                )
            })
        }
    )
}