Enum Value

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pub enum Value {
    Null,
    Array(Vec<Value>),
    Bool(bool),
    Number(Number),
    Object(Map),
    String(String),
}

Expand description

Represents any valid JSON API value.

Like serde_json::Value, but with spec compliance baked into the type system.

Variants§

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Null

A null value.

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Array(Vec<Value>)

An array of values.

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Bool(bool)

A boolean value.

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Number(Number)

An integer or floating point value.

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Object(Map)

A JSON object as a hash table with consistent order. Keys are guarenteed to be a valid member name.

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String(String)

A string value.

Implementations§

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impl Value

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pub fn as_array(&self) -> Option<&[Value]>

Optionally get the underlying vector as a slice. Returns None if the Value is not an array.

§Example

let data = vec![true.into(), false.into()];
let array = Value::Array(data.clone());
let boolean = Value::Bool(true);

assert_eq!(array.as_array(), Some(data.as_slice()));
assert_eq!(boolean.as_array(), None);

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pub fn as_array_mut(&mut self) -> Option<&mut [Value]>

Optionally get the underlying vector as a mutable slice. Returns None if the Value is not an array.

§Example

let mut data = vec![true.into(), false.into()];
let mut array = Value::Array(data.clone());
let mut boolean = Value::Bool(true);

assert_eq!(array.as_array_mut(), Some(data.as_mut_slice()));
assert_eq!(boolean.as_array_mut(), None);

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pub fn as_bool(&self) -> Option<bool>

Optionally get the inner boolean value. Returns None if the Value is not a boolean.

§Example

let boolean = Value::Bool(true);
let number = Value::from(3.14);

assert_eq!(boolean.as_bool(), Some(true));
assert_eq!(number.as_bool(), None);

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pub fn as_null(&self) -> Option<()>

Returns Some(()) if the Value is null.

§Example

let null = Value::Null;
let text = Value::String("Hello, World!".to_owned());

assert_eq!(null.as_null(), Some(()));
assert_eq!(text.as_null(), None);

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pub fn as_object(&self) -> Option<&Map>

Optionally get a reference to the inner map. Returns None if the Value is not an object.

§Example

let data = Map::new();
let object = Value::Object(data.clone());
let number = Value::from(3.14);

assert_eq!(object.as_object(), Some(&data));
assert_eq!(number.as_object(), None);

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pub fn as_object_mut(&mut self) -> Option<&mut Map>

Optionally get a mutable reference to the inner map. Returns None if the Value is not an object.

§Example

let mut data = Map::new();
let mut object = Value::Object(data.clone());
let mut number = Value::from(3.14);

assert_eq!(object.as_object_mut(), Some(&mut data));
assert_eq!(number.as_object_mut(), None);

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pub fn as_str(&self) -> Option<&str>

Optionally get the underlying string as a string slice. Returns None if the Value is not a string.

§Example

let data = "Hello, World!";
let string = Value::String(data.to_owned());
let number = Value::from(3.14);

assert_eq!(string.as_str(), Some(data));
assert_eq!(number.as_str(), None);

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pub fn as_f64(&self) -> Option<f64>

Optionally get the underlying number as an f64. Returns None if the Value cannot be represented as an f64.

§Example

let number = Value::from(3.14);
let string = Value::String("Hello, World!".to_owned());

assert_eq!(number.as_f64(), Some(3.14));
assert_eq!(string.as_f64(), None);

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pub fn as_i64(&self) -> Option<i64>

Optionally get the underlying number as an i64. Returns None if the Value cannot be represented as an i64.

§Example

let integer = Value::from(10);
let float = Value::from(3.14);

assert_eq!(integer.as_i64(), Some(10));
assert_eq!(float.as_i64(), None);

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pub fn as_u64(&self) -> Option<u64>

Optionally get the underlying number as an u64. Returns None if the Value cannot be represented as an u64.

§Example

let positive = Value::from(10);
let negative = Value::from(-10);

assert_eq!(positive.as_u64(), Some(10));
assert_eq!(negative.as_u64(), None);

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pub fn is_array(&self) -> bool

Returns true if the Value is an array.

For any Value on which is_array returns true, as_array and as_array_mut are guaranteed to return a reference to the vector representing the array.

§Example

let mut value = Value::from(vec![1, 2, 3]);

assert!(value.is_array());

value.as_array().unwrap();
value.as_array_mut().unwrap();

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pub fn is_boolean(&self) -> bool

Returns true if the Value is a boolean.

For any Value on which is_boolean returns true, as_bool is guaranteed to return the boolean value.

§Example

let value = Value::Bool(true);

assert!(value.is_boolean());
value.as_bool().unwrap();

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pub fn is_null(&self) -> bool

Returns true if the Value is null.

For any Value on which is_null returns true, as_null is guaranteed to return Some(()).

§Example

let value = Value::Null;

assert!(value.is_null());
value.as_null().unwrap();

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pub fn is_number(&self) -> bool

Returns true if the Value is a number.

§Example

assert!(Value::from(3.14).is_number());

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pub fn is_object(&self) -> bool

Returns true if the Value is an object.

For any Value on which is_array returns true, as_object and as_object_mut are guaranteed to return a reference to the map representing the object.

§Example

let mut value = Value::Object(Default::default());

assert!(value.is_object());

value.as_object().unwrap();
value.as_object_mut().unwrap();

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pub fn is_string(&self) -> bool

Returns true if the Value is a string.

For any Value on which is_string returns true, as_str is guaranteed to return the string slice.

§Example

let value = Value::String("Hello, world!".to_owned());

assert!(value.is_string());
value.as_str().unwrap();

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pub fn is_f64(&self) -> bool

Returns true if the Value is a number that can be represented as an f64.

For any Value on which is_f64 returns true, as_f64 is guaranteed to return the floating point value.

Currently this function returns true if and only if both is_i64 and is_u64 return false. This behavior is not a guarantee in the future.

§Example

let value = Value::from(3.14);

assert!(value.is_f64());
value.as_f64().unwrap();

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pub fn is_i64(&self) -> bool

Returns true if the Value is an integer between i64::MIN and i64::MAX.

For any Value on which is_i64 returns true, as_i64 is guaranteed to return the integer value.

§Example

let pos = Value::from(3);
let neg = Value::from(-3);

assert!(pos.is_i64());
assert!(neg.is_i64());

pos.as_i64().unwrap();
neg.as_i64().unwrap();

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pub fn is_u64(&self) -> bool

Returns true if the Value is an integer between 0 and u64::MAX.

For any Value on which is_u64 returns true, as_u64 is guaranteed to return the integer value.

§Example

let value = Value::from(3);

assert!(value.is_u64());
value.as_u64().unwrap();

Trait Implementations§

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impl Clone for Value

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fn clone(&self) -> Value

Returns a copy of the value. Read more

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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more

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impl Debug for Value

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more

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impl Default for Value

Returns the Value::Null. This allows for better composition with Option types.

§Example

const MSG: &'static str = "Hello, World!";

let opt = None;
let value = opt.map(Value::String).unwrap_or_default();
assert_eq!(value, Value::Null);

let opt = Some(MSG.to_owned());
let value = opt.map(Value::String).unwrap_or_default();
assert_eq!(value, Value::String(MSG.to_owned()));

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fn default() -> Self

Returns the “default value” for a type. Read more

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impl<'de> Deserialize<'de> for Value

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fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer. Read more

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