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
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
//! Structured keys.

use std::borrow::Borrow;
use std::cmp;
use std::fmt;
use std::hash;

/// A type that can be converted into a [`Key`](struct.Key.html).
pub trait ToKey {
    /// Perform the conversion.
    fn to_key(&self) -> Key;
}

impl<'a, T> ToKey for &'a T
where
    T: ToKey + ?Sized,
{
    fn to_key(&self) -> Key {
        (**self).to_key()
    }
}

impl<'k> ToKey for Key<'k> {
    fn to_key(&self) -> Key {
        Key { key: self.key }
    }
}

impl ToKey for str {
    fn to_key(&self) -> Key {
        Key::from_str(self)
    }
}

/// A key in a structured key-value pair.
#[derive(Clone)]
pub struct Key<'k> {
    key: &'k str,
}

impl<'k> Key<'k> {
    /// Get a key from a borrowed string.
    pub fn from_str(key: &'k str) -> Self {
        Key { key: key }
    }

    /// Get a borrowed string from this key.
    pub fn as_str(&self) -> &str {
        self.key
    }
}

impl<'k> fmt::Debug for Key<'k> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.key.fmt(f)
    }
}

impl<'k> fmt::Display for Key<'k> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.key.fmt(f)
    }
}

impl<'k> hash::Hash for Key<'k> {
    fn hash<H>(&self, state: &mut H)
    where
        H: hash::Hasher,
    {
        self.as_str().hash(state)
    }
}

impl<'k, 'ko> PartialEq<Key<'ko>> for Key<'k> {
    fn eq(&self, other: &Key<'ko>) -> bool {
        self.as_str().eq(other.as_str())
    }
}

impl<'k> Eq for Key<'k> {}

impl<'k, 'ko> PartialOrd<Key<'ko>> for Key<'k> {
    fn partial_cmp(&self, other: &Key<'ko>) -> Option<cmp::Ordering> {
        self.as_str().partial_cmp(other.as_str())
    }
}

impl<'k> Ord for Key<'k> {
    fn cmp(&self, other: &Self) -> cmp::Ordering {
        self.as_str().cmp(other.as_str())
    }
}

impl<'k> AsRef<str> for Key<'k> {
    fn as_ref(&self) -> &str {
        self.as_str()
    }
}

impl<'k> Borrow<str> for Key<'k> {
    fn borrow(&self) -> &str {
        self.as_str()
    }
}

impl<'k> From<&'k str> for Key<'k> {
    fn from(s: &'k str) -> Self {
        Key::from_str(s)
    }
}

#[cfg(feature = "std")]
mod std_support {
    use super::*;

    use std::borrow::Cow;

    impl ToKey for String {
        fn to_key(&self) -> Key {
            Key::from_str(self)
        }
    }

    impl<'a> ToKey for Cow<'a, str> {
        fn to_key(&self) -> Key {
            Key::from_str(self)
        }
    }
}

#[cfg(feature = "kv_unstable_sval")]
mod sval_support {
    use super::*;

    extern crate sval;

    use self::sval::value::{self, Value};

    impl<'a> Value for Key<'a> {
        fn stream(&self, stream: &mut value::Stream) -> value::Result {
            self.key.stream(stream)
        }
    }
}

#[cfg(feature = "kv_unstable_serde")]
mod serde_support {
    use super::*;

    extern crate serde;

    use self::serde::{Serialize, Serializer};

    impl<'a> Serialize for Key<'a> {
        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
        where
            S: Serializer,
        {
            self.key.serialize(serializer)
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn key_from_string() {
        assert_eq!("a key", Key::from_str("a key").as_str());
    }
}