undis/resp3/
value.rs

1//! A loosely typed Value enum to represent RESP3 values.
2//!
3//! For more information, see the [`Value`](Value) type.
4
5use std::cmp::{Eq, PartialEq};
6use std::fmt;
7
8use bstr::BString;
9use indexmap::IndexMap;
10use serde::de;
11
12use super::Double;
13
14// TODO: impl Serialize/Deserializer for Value
15
16/// Represents a valid RESP3 value.
17///
18/// This is useful for representing flexible messages like `HELLO` response,
19/// or to _see_ the structure of some [`.raw_command()`](crate::Client::raw_command) responses.
20#[derive(Debug, Clone, PartialEq, Eq)]
21pub enum Value {
22    /// Null value.
23    Null,
24    /// Binary string. Can be obtained from simple string, blob string, blob string stream.
25    /// It conventionally but not necessarily is a UTF-8 encoded string.
26    Blob(BString),
27    /// Boolean value.
28    Boolean(bool),
29    /// Integer value in the form of i128.
30    /// This type doesn't support numbers which can't be represented within this range
31    /// though the RESP3 protocol itself supports arbitrary big integers.
32    Number(i128),
33    /// Double precision floating point number which can't be NaN.
34    Double(Double),
35    /// Array of values.
36    Array(Vec<Value>),
37    /// Map of values, keyed by binary strings.
38    /// Order is preserved in order to print Hello response nicely.
39    Map(IndexMap<BString, Value>),
40}
41
42impl Default for Value {
43    fn default() -> Self {
44        Value::Null
45    }
46}
47
48impl<'de> de::Deserialize<'de> for Value {
49    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
50    where
51        D: serde::Deserializer<'de>,
52    {
53        struct Visitor;
54
55        impl<'de> de::Visitor<'de> for Visitor {
56            type Value = Value;
57
58            fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
59                f.write_str("any valid RESP3 value")
60            }
61
62            fn visit_bool<E>(self, v: bool) -> Result<Self::Value, E>
63            where
64                E: de::Error,
65            {
66                Ok(Value::Boolean(v))
67            }
68
69            fn visit_i64<E>(self, v: i64) -> Result<Self::Value, E>
70            where
71                E: de::Error,
72            {
73                Ok(Value::Number(v.into()))
74            }
75
76            fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
77            where
78                E: de::Error,
79            {
80                Ok(Value::Number(v))
81            }
82
83            fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E>
84            where
85                E: de::Error,
86            {
87                Ok(Value::Number(v.into()))
88            }
89
90            fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
91            where
92                E: de::Error,
93            {
94                Ok(Value::Number(v.try_into().map_err(|_| {
95                    E::custom("number cannot be represented within the i128 range")
96                })?))
97            }
98
99            fn visit_f64<E>(self, v: f64) -> Result<Self::Value, E>
100            where
101                E: de::Error,
102            {
103                if v.is_nan() {
104                    return Err(E::custom("NaN is not allowed"));
105                }
106
107                Ok(Value::Double(Double::new(v)))
108            }
109
110            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
111            where
112                E: de::Error,
113            {
114                Ok(Value::Blob(v.into()))
115            }
116
117            fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
118            where
119                E: de::Error,
120            {
121                Ok(Value::Blob(v.into()))
122            }
123
124            fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
125            where
126                E: de::Error,
127            {
128                Ok(Value::Blob(v.into()))
129            }
130
131            fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
132            where
133                E: de::Error,
134            {
135                Ok(Value::Blob(v.into()))
136            }
137
138            fn visit_unit<E>(self) -> Result<Self::Value, E>
139            where
140                E: de::Error,
141            {
142                Ok(Value::Null)
143            }
144
145            fn visit_none<E>(self) -> Result<Self::Value, E>
146            where
147                E: de::Error,
148            {
149                Ok(Value::Null)
150            }
151
152            fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
153            where
154                D: serde::Deserializer<'de>,
155            {
156                de::Deserialize::deserialize(deserializer)
157            }
158
159            fn visit_seq<A>(self, mut access: A) -> Result<Self::Value, A::Error>
160            where
161                A: de::SeqAccess<'de>,
162            {
163                let mut vec = Vec::new();
164
165                while let Some(elem) = access.next_element()? {
166                    vec.push(elem);
167                }
168
169                Ok(Value::Array(vec))
170            }
171
172            fn visit_map<A>(self, mut access: A) -> Result<Self::Value, A::Error>
173            where
174                A: de::MapAccess<'de>,
175            {
176                let mut map = IndexMap::new();
177
178                while let Some((key, value)) = access.next_entry()? {
179                    map.insert(key, value);
180                }
181
182                Ok(Value::Map(map))
183            }
184        }
185
186        deserializer.deserialize_any(Visitor)
187    }
188}
undis/resp3/value.rs

undis/resp3/
value.rs
