indexmap/
macros.rs

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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
#[macro_export]
/// Create an [`IndexMap`][crate::IndexMap] from a list of key-value pairs
///
/// ## Example
///
/// ```
/// use indexmap::indexmap;
///
/// let map = indexmap!{
///     "a" => 1,
///     "b" => 2,
/// };
/// assert_eq!(map["a"], 1);
/// assert_eq!(map["b"], 2);
/// assert_eq!(map.get("c"), None);
///
/// // "a" is the first key
/// assert_eq!(map.keys().next(), Some(&"a"));
/// ```
macro_rules! indexmap {
    ($($key:expr => $value:expr,)+) => { $crate::indexmap!($($key => $value),+) };
    ($($key:expr => $value:expr),*) => {
        {
            // Note: `stringify!($key)` is just here to consume the repetition,
            // but we throw away that string literal during constant evaluation.
            const CAP: usize = <[()]>::len(&[$({ stringify!($key); }),*]);
            let mut map = $crate::IndexMap::with_capacity(CAP);
            $(
                map.insert($key, $value);
            )*
            map
        }
    };
}

#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
#[macro_export]
/// Create an [`IndexSet`][crate::IndexSet] from a list of values
///
/// ## Example
///
/// ```
/// use indexmap::indexset;
///
/// let set = indexset!{
///     "a",
///     "b",
/// };
/// assert!(set.contains("a"));
/// assert!(set.contains("b"));
/// assert!(!set.contains("c"));
///
/// // "a" is the first value
/// assert_eq!(set.iter().next(), Some(&"a"));
/// ```
macro_rules! indexset {
    ($($value:expr,)+) => { $crate::indexset!($($value),+) };
    ($($value:expr),*) => {
        {
            // Note: `stringify!($value)` is just here to consume the repetition,
            // but we throw away that string literal during constant evaluation.
            const CAP: usize = <[()]>::len(&[$({ stringify!($value); }),*]);
            let mut set = $crate::IndexSet::with_capacity(CAP);
            $(
                set.insert($value);
            )*
            set
        }
    };
}

// generate all the Iterator methods by just forwarding to the underlying
// self.iter and mapping its element.
macro_rules! iterator_methods {
    // $map_elt is the mapping function from the underlying iterator's element
    // same mapping function for both options and iterators
    ($map_elt:expr) => {
        fn next(&mut self) -> Option<Self::Item> {
            self.iter.next().map($map_elt)
        }

        fn size_hint(&self) -> (usize, Option<usize>) {
            self.iter.size_hint()
        }

        fn count(self) -> usize {
            self.iter.len()
        }

        fn nth(&mut self, n: usize) -> Option<Self::Item> {
            self.iter.nth(n).map($map_elt)
        }

        fn last(mut self) -> Option<Self::Item> {
            self.next_back()
        }

        fn collect<C>(self) -> C
        where
            C: FromIterator<Self::Item>,
        {
            // NB: forwarding this directly to standard iterators will
            // allow it to leverage unstable traits like `TrustedLen`.
            self.iter.map($map_elt).collect()
        }
    };
}

macro_rules! double_ended_iterator_methods {
    // $map_elt is the mapping function from the underlying iterator's element
    // same mapping function for both options and iterators
    ($map_elt:expr) => {
        fn next_back(&mut self) -> Option<Self::Item> {
            self.iter.next_back().map($map_elt)
        }

        fn nth_back(&mut self, n: usize) -> Option<Self::Item> {
            self.iter.nth_back(n).map($map_elt)
        }
    };
}

// generate `ParallelIterator` methods by just forwarding to the underlying
// self.entries and mapping its elements.
#[cfg(any(feature = "rayon", feature = "rustc-rayon"))]
macro_rules! parallel_iterator_methods {
    // $map_elt is the mapping function from the underlying iterator's element
    ($map_elt:expr) => {
        fn drive_unindexed<C>(self, consumer: C) -> C::Result
        where
            C: UnindexedConsumer<Self::Item>,
        {
            self.entries
                .into_par_iter()
                .map($map_elt)
                .drive_unindexed(consumer)
        }

        // NB: This allows indexed collection, e.g. directly into a `Vec`, but the
        // underlying iterator must really be indexed.  We should remove this if we
        // start having tombstones that must be filtered out.
        fn opt_len(&self) -> Option<usize> {
            Some(self.entries.len())
        }
    };
}

// generate `IndexedParallelIterator` methods by just forwarding to the underlying
// self.entries and mapping its elements.
#[cfg(any(feature = "rayon", feature = "rustc-rayon"))]
macro_rules! indexed_parallel_iterator_methods {
    // $map_elt is the mapping function from the underlying iterator's element
    ($map_elt:expr) => {
        fn drive<C>(self, consumer: C) -> C::Result
        where
            C: Consumer<Self::Item>,
        {
            self.entries.into_par_iter().map($map_elt).drive(consumer)
        }

        fn len(&self) -> usize {
            self.entries.len()
        }

        fn with_producer<CB>(self, callback: CB) -> CB::Output
        where
            CB: ProducerCallback<Self::Item>,
        {
            self.entries
                .into_par_iter()
                .map($map_elt)
                .with_producer(callback)
        }
    };
}