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
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135

use crate::error::DemesError;
use serde::{Deserialize, Serialize};

/// An ancestry proportion.
///
/// This is a newtype wrapper for [`f64`](std::primitive::f64).
///
/// # Interpretation
///
/// With respect to a deme in an *offspring* time step,
/// a proportion is the fraction of ancsestry from a given
/// parental deme.
///
/// # Examples
///
/// ## In `YAML` input
///
/// ### Ancestral proportions of demes
///
/// ```
/// let yaml = "
/// time_units: generations
/// description:
///   An admixed deme appears 100 generations ago.
///   Its initial ancestry is 90% from ancestor1
///   and 10% from ancestor2.
/// demes:
///  - name: ancestor1
///    epochs:
///     - start_size: 50
///       end_time: 100
///  - name: ancestor2
///    epochs:
///     - start_size: 50
///       end_time: 100
///  - name: admixed
///    ancestors: [ancestor1, ancestor2]
///    proportions: [0.9, 0.1]
///    start_time: 100
///    epochs:
///     - start_size: 200
/// ";
/// demes::loads(yaml).unwrap();
/// ```
///
/// ### Pulse proportions
///
/// ```
/// let yaml = "
/// time_units: generations
/// description:
///    Two demes coexist without migration.
///    Sixty three (63) generations ago,
///    deme1 contributes 50% of ancestry
///    to all individuals born in deme2.
/// demes:
///  - name: deme1
///    epochs:
///     - start_size: 50
///  - name: deme2
///    epochs:
///     - start_size: 50
/// pulses:
///  - sources: [deme1]
///    dest: deme2
///    proportions: [0.5]
///    time: 63
/// ";
/// demes::loads(yaml).unwrap();
/// ```
///
/// ## Using rust code
///
/// ```
/// let t = demes::Proportion::try_from(0.5).unwrap();
/// assert_eq!(t, 0.5);
/// ```
#[derive(Clone, Copy, Debug, Serialize, Deserialize)]
#[repr(transparent)]
#[serde(try_from = "f64")]
pub struct Proportion(f64);

impl Proportion {
    fn validate<F>(&self, f: F) -> Result<(), DemesError>
    where
        F: std::ops::FnOnce(String) -> DemesError,
    {
        if !self.0.is_finite() || self.0 <= 0.0 || self.0 > 1.0 {
            let msg = format!("proportions must be 0.0 < p <= 1.0, got: {}", self.0);
            Err(f(msg))
        } else {
            Ok(())
        }
    }
}

impl TryFrom<f64> for Proportion {
    type Error = DemesError;
    fn try_from(value: f64) -> Result<Self, Self::Error> {
        let rv = Self(value);
        rv.validate(DemesError::ValueError)?;
        Ok(rv)
    }
}

impl_newtype_traits!(Proportion);

/// Input value for [`Proportion`], used when loading or building graphs.
///
/// # Examples
///
/// ```
/// let t = demes::InputProportion::from(1.0);
/// assert_eq!(t, 1.0);
/// let t = t - 1.0;
/// assert_eq!(t, 0.0);
/// let t = 1.0 + t;
/// assert_eq!(t, 1.0);
/// ```
#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, PartialOrd)]
#[repr(transparent)]
#[serde(from = "f64")]
pub struct InputProportion(f64);

impl_input_newtype_traits!(InputProportion);

impl TryFrom<InputProportion> for Proportion {
    type Error = DemesError;

    fn try_from(value: InputProportion) -> Result<Self, Self::Error> {
        let rv = Self(value.0);
        rv.validate(DemesError::ValueError)?;
        Ok(rv)
    }
}