martin 1.5.0

Blazing fast and lightweight tile server with PostGIS, MBTiles, and PMTiles support
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
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
136
137
138
139
140
141
142
143
144
145
146
147
148
149

use std::vec::IntoIter;

use serde::{Deserialize, Serialize};

/// An enum that can hold no values, one value, or many values of type T.
#[derive(Debug, Default, Clone, PartialEq, Serialize, Deserialize)]
#[serde(untagged)]
pub enum OptOneMany<T> {
    /// No values present.
    #[default]
    NoVals,
    /// Exactly one value present.
    One(T),
    /// Multiple values present.
    Many(Vec<T>),
}

impl<T> IntoIterator for OptOneMany<T> {
    type Item = T;
    type IntoIter = IntoIter<T>;

    fn into_iter(self) -> Self::IntoIter {
        match self {
            Self::NoVals => Vec::new().into_iter(),
            Self::One(v) => vec![v].into_iter(),
            Self::Many(v) => v.into_iter(),
        }
    }
}

impl<T> OptOneMany<T> {
    /// Creates a new `OptOneMany` from an iterator.
    ///
    /// Returns `NoVals` if the iterator is empty, `One` if it contains exactly one item,
    /// and `Many` if it contains multiple items.
    pub fn new<I: IntoIterator<Item = T>>(iter: I) -> Self {
        let mut iter = iter.into_iter();
        match (iter.next(), iter.next()) {
            (Some(first), Some(second)) => {
                let mut vec = Vec::with_capacity(iter.size_hint().0 + 2);
                vec.push(first);
                vec.push(second);
                vec.extend(iter);
                Self::Many(vec)
            }
            (Some(first), None) => Self::One(first),
            (None, _) => Self::NoVals,
        }
    }

    /// Returns `true` if this contains no values.
    pub fn is_none(&self) -> bool {
        matches!(self, Self::NoVals)
    }

    /// Returns `true` if this contains no values or an empty vector.
    pub fn is_empty(&self) -> bool {
        match self {
            Self::NoVals => true,
            Self::One(_) => false,
            Self::Many(v) => v.is_empty(),
        }
    }

    /// Returns an iterator over the contained values.
    pub fn iter(&self) -> impl Iterator<Item = &T> {
        match self {
            Self::NoVals => [].iter(),
            Self::One(v) => std::slice::from_ref(v).iter(),
            Self::Many(v) => v.iter(),
        }
    }

    /// Returns an optional iterator over the contained values.
    ///
    /// Returns `None` for `NoVals`, `Some(iterator)` for `One` and `Many`.
    pub fn opt_iter(&self) -> Option<impl Iterator<Item = &T>> {
        match self {
            Self::NoVals => None,
            Self::One(v) => Some(std::slice::from_ref(v).iter()),
            Self::Many(v) => Some(v.iter()),
        }
    }

    /// Returns a mutable iterator over the contained values.
    pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut T> {
        match self {
            Self::NoVals => [].iter_mut(),
            Self::One(v) => std::slice::from_mut(v).iter_mut(),
            Self::Many(v) => v.iter_mut(),
        }
    }

    /// Returns a slice view of the contained values.
    pub fn as_slice(&self) -> &[T] {
        match self {
            Self::NoVals => &[],
            Self::One(item) => std::slice::from_ref(item),
            Self::Many(v) => v.as_slice(),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::OptOneMany::{Many, NoVals, One};
    use super::*;

    #[test]
    fn test_one_or_many_new() {
        assert_eq!(OptOneMany::new(vec![1, 2, 3]), Many(vec![1, 2, 3]));
        assert_eq!(OptOneMany::new(vec![1]), One(1));
        assert_eq!(OptOneMany::new(Vec::<i32>::new()), NoVals);
    }

    #[test]
    fn test_one_or_many_iter() {
        let mut noval: OptOneMany<i32> = NoVals;
        let mut one = One(1);
        let mut many = Many(vec![1, 2, 3]);

        assert_eq!(noval.iter_mut().collect::<Vec<_>>(), Vec::<&i32>::new());
        assert_eq!(one.iter_mut().collect::<Vec<_>>(), vec![&1]);
        assert_eq!(many.iter_mut().collect::<Vec<_>>(), vec![&1, &2, &3]);

        assert_eq!(noval.iter().collect::<Vec<_>>(), Vec::<&i32>::new());
        assert_eq!(one.iter().collect::<Vec<_>>(), vec![&1]);
        assert_eq!(many.iter().collect::<Vec<_>>(), vec![&1, &2, &3]);

        assert_eq!(noval.opt_iter().map(Iterator::collect::<Vec<_>>), None);
        assert_eq!(one.opt_iter().map(Iterator::collect), Some(vec![&1]));
        assert_eq!(
            many.opt_iter().map(Iterator::collect),
            Some(vec![&1, &2, &3])
        );

        assert_eq!(noval.into_iter().collect::<Vec<_>>(), Vec::<i32>::new());
        assert_eq!(one.into_iter().collect::<Vec<_>>(), vec![1]);
        assert_eq!(many.into_iter().collect::<Vec<_>>(), vec![1, 2, 3]);
    }

    #[test]
    fn test_one_or_many_as_slice() {
        let noval: OptOneMany<i32> = NoVals;
        assert_eq!(noval.as_slice(), Vec::<i32>::new().as_slice());
        assert_eq!(One(1).as_slice(), &[1]);
        assert_eq!(Many(vec![1, 2, 3]).as_slice(), &[1, 2, 3]);
    }
}