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

use std::ops::Deref;

use ref_cast::RefCast;

use crate::http::RawStr;

/// A field name key composed of indices.
///
/// A form field name key is composed of _indices_, delimited by `:`. The
/// graphic below illustrates this composition for a single field in
/// `$name=$value` format:
///
/// ```text
///       food.bart[bar:foo:baz]=some-value
/// name  |--------------------|
/// key   |--| |--| |---------|
/// index |--| |--| |-| |-| |-|
/// ```
///
/// A `Key` is a wrapper around a given key string with methods to easily access
/// its indices.
///
/// # Serialization
///
/// A value of this type is serialized exactly as an `&str` consisting of the
/// entire key.
#[repr(transparent)]
#[derive(RefCast, Debug, PartialEq, Eq, Hash)]
pub struct Key(str);

impl Key {
    /// Wraps a string as a `Key`. This is cost-free.
    ///
    /// # Example
    ///
    /// ```rust
    /// use rocket::form::name::Key;
    ///
    /// let key = Key::new("a:b:c");
    /// assert_eq!(key.as_str(), "a:b:c");
    /// ```
    pub fn new<S: AsRef<str> + ?Sized>(string: &S) -> &Key {
        Key::ref_cast(string.as_ref())
    }

    /// Returns an iterator over the indices of `self`, including empty indices.
    ///
    /// See the [top-level docs](Self) for a description of "indices".
    ///
    /// # Example
    ///
    /// ```rust
    /// use rocket::form::name::Key;
    ///
    /// let key = Key::new("foo:bar::baz:a.b.c");
    /// let indices: Vec<_> = key.indices().collect();
    /// assert_eq!(indices, &["foo", "bar", "", "baz", "a.b.c"]);
    /// ```
    pub fn indices(&self) -> impl Iterator<Item = &str> {
        self.split(':')
    }

    /// Borrows the underlying string.
    ///
    /// # Example
    ///
    /// ```rust
    /// use rocket::form::name::Key;
    ///
    /// let key = Key::new("a:b:c");
    /// assert_eq!(key.as_str(), "a:b:c");
    /// ```
    pub fn as_str(&self) -> &str {
        &*self
    }
}

impl Deref for Key {
    type Target = str;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl serde::Serialize for Key {
    fn serialize<S>(&self, ser: S) -> Result<S::Ok, S::Error>
        where S: serde::Serializer
    {
        self.0.serialize(ser)
    }
}

impl<'de: 'a, 'a> serde::Deserialize<'de> for &'a Key {
    fn deserialize<D>(de: D) -> Result<Self, D::Error>
        where D: serde::Deserializer<'de>
    {
        <&'a str as serde::Deserialize<'de>>::deserialize(de).map(Key::new)
    }
}

impl<I: core::slice::SliceIndex<str, Output=str>> core::ops::Index<I> for Key {
    type Output = Key;

    #[inline]
    fn index(&self, index: I) -> &Self::Output {
        self.0[index].into()
    }
}

impl PartialEq<str> for Key {
    fn eq(&self, other: &str) -> bool {
        self == Key::new(other)
    }
}

impl PartialEq<Key> for str {
    fn eq(&self, other: &Key) -> bool {
        Key::new(self) == other
    }
}

impl<'a, S: AsRef<str> + ?Sized> From<&'a S> for &'a Key {
    #[inline]
    fn from(string: &'a S) -> Self {
        Key::new(string)
    }
}

impl AsRef<Key> for str {
    fn as_ref(&self) -> &Key {
        Key::new(self)
    }
}

impl AsRef<Key> for RawStr {
    fn as_ref(&self) -> &Key {
        Key::new(self)
    }
}

impl std::fmt::Display for Key {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        self.0.fmt(f)
    }
}