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

//! An order-preserving immutable set constructed at compile time.
use core::borrow::Borrow;
use core::iter::IntoIterator;
use core::fmt;
use ordered_map;
use {PhfHash, OrderedMap};

/// An order-preserving immutable set constructed at compile time.
///
/// Unlike a `Set`, iteration order is guaranteed to match the definition
/// order.
///
/// ## Note
///
/// The fields of this struct are public so that they may be initialized by the
/// `phf_ordered_set!` macro and code generation. They are subject to change at
/// any time and should never be accessed directly.
pub struct OrderedSet<T: 'static> {
    #[doc(hidden)]
    pub map: OrderedMap<T, ()>,
}

impl<T> fmt::Debug for OrderedSet<T> where T: fmt::Debug {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_set().entries(self).finish()
    }
}

impl<T> OrderedSet<T> {
    /// Returns the number of elements in the `OrderedSet`.
    pub fn len(&self) -> usize {
        self.map.len()
    }

    /// Returns true if the `OrderedSet` contains no elements.
    pub fn is_empty(&self) -> bool {
        self.len() == 0
    }

    /// Returns a reference to the set's internal static instance of the given
    /// key.
    ///
    /// This can be useful for interning schemes.
    pub fn get_key<U: ?Sized>(&self, key: &U) -> Option<&T>
        where U: Eq + PhfHash,
              T: Borrow<U>
    {
        self.map.get_key(key)
    }

    /// Returns the index of the key within the list used to initialize
    /// the ordered set.
    pub fn get_index<U: ?Sized>(&self, key: &U) -> Option<usize>
        where U: Eq + PhfHash,
              T: Borrow<U>
    {
        self.map.get_index(key)
    }

    /// Returns a reference to the key at an index
    /// within the list used to initialize the ordered set. See `.get_index(key)`.
    pub fn index(&self, index: usize) -> Option<&T> {
        self.map.index(index).map(|(k, &())| k)
    }

    /// Returns true if `value` is in the `Set`.
    pub fn contains<U: ?Sized>(&self, value: &U) -> bool
        where U: Eq + PhfHash,
              T: Borrow<U>
    {
        self.map.contains_key(value)
    }

    /// Returns an iterator over the values in the set.
    ///
    /// Values are returned in the same order in which they were defined.
    pub fn iter<'a>(&'a self) -> Iter<'a, T> {
        Iter { iter: self.map.keys() }
    }
}

impl<T> OrderedSet<T> where T: Eq + PhfHash {
    /// Returns true if `other` shares no elements with `self`.
    #[inline]
    pub fn is_disjoint(&self, other: &OrderedSet<T>) -> bool {
        !self.iter().any(|value| other.contains(value))
    }

    /// Returns true if `other` contains all values in `self`.
    #[inline]
    pub fn is_subset(&self, other: &OrderedSet<T>) -> bool {
        self.iter().all(|value| other.contains(value))
    }

    /// Returns true if `self` contains all values in `other`.
    #[inline]
    pub fn is_superset(&self, other: &OrderedSet<T>) -> bool {
        other.is_subset(self)
    }
}

impl<'a, T> IntoIterator for &'a OrderedSet<T> {
    type Item = &'a T;
    type IntoIter = Iter<'a, T>;

    fn into_iter(self) -> Iter<'a, T> {
        self.iter()
    }
}

/// An iterator over the values in a `OrderedSet`.
pub struct Iter<'a, T: 'a> {
    iter: ordered_map::Keys<'a, T, ()>,
}

impl<'a, T> Iterator for Iter<'a, T> {
    type Item = &'a T;

    #[inline]
    fn next(&mut self) -> Option<&'a T> {
        self.iter.next()
    }

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

impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
    #[inline]
    fn next_back(&mut self) -> Option<&'a T> {
        self.iter.next_back()
    }
}

impl<'a, T> ExactSizeIterator for Iter<'a, T> {}