logo
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

//! This module implements some useful objects.

use std::iter;
use std::collections::HashMap;
use std::collections::hash_map;


/// `MultiDict` list entries iterator.
type MultiDictListIter<'a, T> = hash_map::Iter<'a, String, Vec<T>>;
/// `MultiDict` list values iterator.
type MultiDictListValues<'a, T> = hash_map::Values<'a, String, Vec<T>>;

/// `MultiDict` values iterator.
pub struct MultiDictValues<'a, T: 'a> {
    inner: iter::Map<MultiDictListValues<'a, T>, fn(&'a Vec<T>) -> &'a T>
}

impl<'a, T: 'a> iter::Iterator for MultiDictValues<'a, T> {
    type Item = &'a T;

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

/// `MultiDict` entries iterator.
pub struct MultiDictIter<'a, T: 'a> {
    inner: iter::Map<MultiDictListIter<'a, T>, for<'b, 'c> fn((&'b String, &'c Vec<T>)) -> (&'b String, &'c T)>
}

impl<'a, T: 'a> iter::Iterator for MultiDictIter<'a, T> {
    type Item = (&'a String, &'a T);

    #[inline] fn next(&mut self) -> Option<(&'a String, &'a T)> { self.inner.next() }
    #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
}

/// This is used to deal with multiple values for the same key.
#[derive(Clone, Debug)]
pub struct MultiDict<T> {
    map: HashMap<String, Vec<T>>,
}

use std::borrow::Borrow;

impl<T> MultiDict<T> {
    pub fn new() -> MultiDict<T> {
        MultiDict {
            map: HashMap::new(),
        }
    }

    /// Return the first value for this key.
    pub fn get<B>(&self, key: &str) -> Option<&B>
        where T: Borrow<B>,
              B: ?Sized
    {
        match self.map.get(key) {
            Some(value) => Some(value[0].borrow()),
            None => None
        }
    }

    /// Removes an existing key first and add the value.
    pub fn set(&mut self, key: &str, value: T) {
        self.map.insert(key.to_owned(), vec![value]);
    }

    /// Adds a new value for the key.
    pub fn add(&mut self, key: String, value: T) {
        match self.map.remove(&key) {
            Some(mut v) => {
                v.push(value);
                self.map.insert(key, v);
            },
            None => {
                self.map.insert(key, vec![value]);
            },
        }
    }

    /// Return the list of items for a given key.
    pub fn getlist(&self, key: &str) -> Option<&Vec<T>> {
        self.map.get(key)
    }
    
    /// An iterator of `(key, value)` pairs.
    /// The value will be first value of each key.
    pub fn iter<'a>(&'a self) -> MultiDictIter<'a, T> {
        fn first<'a, 'b, A, B>(kvpair: (&'a A, &'b Vec<B>)) -> (&'a A, &'b B) { (kvpair.0, &kvpair.1[0]) }
        let first: for<'b, 'c> fn((&'b String, &'c Vec<T>)) -> (&'b String, &'c T) = first;
        MultiDictIter { inner: self.listiter().map(first) }
    }

    /// An iterator of `(key, values)` pairs.
    pub fn listiter<'a>(&'a self) -> hash_map::Iter<'a, String, Vec<T>> {
        self.map.iter()
    }

    /// An iterator visiting all keys in arbitrary order.
    pub fn keys<'a>(&'a self) -> hash_map::Keys<'a, String, Vec<T>> {
        self.map.keys()
    }

    /// An iterator of the first value on every key's value list.
    pub fn values<'a>(&'a self) -> MultiDictValues<'a, T> {
        fn first<'a, A>(list: &'a Vec<A>) -> &'a A { &list[0] }
        let first: for<'b> fn(&'b Vec<T>) -> &'b T = first;
        MultiDictValues { inner: self.listvalues().map(first) }
    }

    /// An iterator of all values corresponding to a key.
    pub fn listvalues<'a>(&'a self) -> hash_map::Values<'a, String, Vec<T>> {
        self.map.values()
    }
}