Enum serde_json::value::Value

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

Represents any valid JSON value.

Variants

Null

Represents a JSON null value.

Bool(bool)

Represents a JSON boolean.

Number(Number)

Represents a JSON number, whether integer or floating point.

String(String)

Represents a JSON string.

Array(Vec<Value>)

Represents a JSON array.

Object(Map<String, Value>)

Represents a JSON object.

Methods

impl Value

fn find<'a>(&'a self, key: &str) -> Option<&'a Value>

If the Value is an Object, returns the value associated with the provided key. Otherwise, returns None.

fn find_path<'a>(&'a self, keys: &[&str]) -> Option<&'a Value>

Attempts to get a nested Value Object for each key in keys. If any key is found not to exist, find_path will return None. Otherwise, it will return the Value associated with the final key.

fn pointer<'a>(&'a self, pointer: &str) -> Option<&'a Value>

Looks up a value by a JSON Pointer.

JSON Pointer defines a string syntax for identifying a specific value within a JavaScript Object Notation (JSON) document.

A Pointer is a Unicode string with the reference tokens separated by /. Inside tokens / is replaced by ~1 and ~ is replaced by ~0. The addressed value is returned and if there is no such value None is returned.

For more information read RFC6901.

fn pointer_mut<'a>(&'a mut self, pointer: &str) -> Option<&'a mut Value>

Looks up a value by a JSON Pointer and returns a mutable reference to that value.

JSON Pointer defines a string syntax for identifying a specific value within a JavaScript Object Notation (JSON) document.

A Pointer is a Unicode string with the reference tokens separated by /. Inside tokens / is replaced by ~1 and ~ is replaced by ~0. The addressed value is returned and if there is no such value None is returned.

For more information read RFC6901.

Example of Use

extern crate serde_json;

use serde_json::Value;
use std::mem;

fn main() {
    let s = r#"{"x": 1.0, "y": 2.0}"#;
    let mut value: Value = serde_json::from_str(s).unwrap();

    // Check value using read-only pointer
    assert_eq!(value.pointer("/x"), Some(&1.0.into()));
    // Change value with direct assignment
    *value.pointer_mut("/x").unwrap() = 1.5.into();
    // Check that new value was written
    assert_eq!(value.pointer("/x"), Some(&1.5.into()));

    // "Steal" ownership of a value. Can replace with any valid Value.
    let old_x = value.pointer_mut("/x").map(|x| mem::replace(x, Value::Null)).unwrap();
    assert_eq!(old_x, 1.5.into());
    assert_eq!(value.pointer("/x").unwrap(), &Value::Null);
}

fn search<'a>(&'a self, key: &str) -> Option<&'a Value>

If the Value is an Object, performs a depth-first search until a value associated with the provided key is found. If no value is found or the Value is not an Object, returns None.

fn is_object(&self) -> bool

Returns true if the Value is an Object. Returns false otherwise.

fn as_object(&self) -> Option<&Map<String, Value>>

If the Value is an Object, returns the associated Map. Returns None otherwise.

fn as_object_mut(&mut self) -> Option<&mut Map<String, Value>>

If the Value is an Object, returns the associated mutable Map. Returns None otherwise.

fn is_array(&self) -> bool

Returns true if the Value is an Array. Returns false otherwise.

fn as_array(&self) -> Option<&Vec<Value>>

If the Value is an Array, returns the associated vector. Returns None otherwise.

fn as_array_mut(&mut self) -> Option<&mut Vec<Value>>

If the Value is an Array, returns the associated mutable vector. Returns None otherwise.

fn is_string(&self) -> bool

Returns true if the Value is a String. Returns false otherwise.

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

If the Value is a String, returns the associated str. Returns None otherwise.

fn is_number(&self) -> bool

Returns true if the Value is a Number. Returns false otherwise.

fn is_i64(&self) -> bool

Returns true if the Value is a number that can be represented by i64.

fn is_u64(&self) -> bool

Returns true if the Value is a number that can be represented by u64.

fn is_f64(&self) -> bool

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

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

If the Value is a number, represent it as i64 if possible. Returns None otherwise.

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

If the Value is a number, represent it as u64 if possible. Returns None otherwise.

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

If the Value is a number, represent it as f64 if possible. Returns None otherwise.

fn is_boolean(&self) -> bool

Returns true if the Value is a Boolean. Returns false otherwise.

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

If the Value is a Boolean, returns the associated bool. Returns None otherwise.

fn is_null(&self) -> bool

Returns true if the Value is a Null. Returns false otherwise.

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

If the Value is a Null, returns (). Returns None otherwise.

Trait Implementations

impl Debug for Value

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Clone for Value

fn clone(&self) -> Value

Returns a copy of the value.

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

Performs copy-assignment from source.

impl PartialEq for Value

fn eq(&self, __arg_0: &Value) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, __arg_0: &Value) -> bool

This method tests for !=.

impl From<i8> for Value

fn from(n: i8) -> Self

Performs the conversion.

impl From<i16> for Value

fn from(n: i16) -> Self

Performs the conversion.

impl From<i32> for Value

fn from(n: i32) -> Self

Performs the conversion.

impl From<i64> for Value

fn from(n: i64) -> Self

Performs the conversion.

impl From<isize> for Value

fn from(n: isize) -> Self

Performs the conversion.

impl From<u8> for Value

fn from(n: u8) -> Self

Performs the conversion.

impl From<u16> for Value

fn from(n: u16) -> Self

Performs the conversion.

impl From<u32> for Value

fn from(n: u32) -> Self

Performs the conversion.

impl From<u64> for Value

fn from(n: u64) -> Self

Performs the conversion.

impl From<usize> for Value

fn from(n: usize) -> Self

Performs the conversion.

impl From<f32> for Value

fn from(f: f32) -> Self

Performs the conversion.

impl From<f64> for Value

fn from(f: f64) -> Self

Performs the conversion.

impl Serialize for Value

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer

Serializes this value into this serializer.

impl Deserialize for Value

fn deserialize<D>(deserializer: D) -> Result<Value, D::Error> where D: Deserializer

Deserialize this value given this Deserializer.

impl Display for Value

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

Serializes a json value into a string

impl FromStr for Value

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Value, Error>

Parses a string s to return a value of this type.

impl Deserializer for Value

type Error = Error

The error type that can be returned if some error occurs during deserialization.

fn deserialize<V>(self, visitor: V) -> Result<V::Value, Error> where V: Visitor

This method walks a visitor through a value as it is being deserialized.

fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Error> where V: Visitor

This method hints that the Deserialize type is expecting an Option value. This allows deserializers that encode an optional value as a nullable value to convert the null value into a None, and a regular value as Some(value).

fn deserialize_enum<V>(self,
                       _name: &str,
                       _variants: &'static [&'static str],
                       visitor: V)
                       -> Result<V::Value, Error> where V: Visitor

This method hints that the Deserialize type is expecting an enum value. This allows deserializers that provide a custom enumeration serialization to properly deserialize the type.

fn deserialize_newtype_struct<V>(self,
                                 _name: &'static str,
                                 visitor: V)
                                 -> Result<V::Value, Self::Error> where V: Visitor

This method hints that the Deserialize type is expecting a newtype struct. This allows deserializers to a newtype struct that aren't tagged as a newtype struct. A reasonable default is to simply deserialize the expected value directly.

fn deserialize_bool<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a bool value.

fn deserialize_usize<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an usize value. A reasonable default is to forward to deserialize_u64.

fn deserialize_u8<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an u8 value. A reasonable default is to forward to deserialize_u64.

fn deserialize_u16<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an u16 value. A reasonable default is to forward to deserialize_u64.

fn deserialize_u32<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an u32 value. A reasonable default is to forward to deserialize_u64.

fn deserialize_u64<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an u64 value.

fn deserialize_isize<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an isize value. A reasonable default is to forward to deserialize_i64.

fn deserialize_i8<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an i8 value. A reasonable default is to forward to deserialize_i64.

fn deserialize_i16<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an i16 value. A reasonable default is to forward to deserialize_i64.

fn deserialize_i32<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an i32 value. A reasonable default is to forward to deserialize_i64.

fn deserialize_i64<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an i64 value.

fn deserialize_f32<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a f32 value. A reasonable default is to forward to deserialize_f64.

fn deserialize_f64<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a f64 value.

fn deserialize_char<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a char value.

fn deserialize_str<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a &str value.

fn deserialize_string<__V>(self,
                           visitor: __V)
                           -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a String value.

fn deserialize_unit<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting an unit value.

fn deserialize_seq<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a sequence value. This allows deserializers to parse sequences that aren't tagged as sequences.

fn deserialize_seq_fixed_size<__V>(self,
                                   _: usize,
                                   visitor: __V)
                                   -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a fixed size array. This allows deserializers to parse arrays that aren't tagged as arrays.

fn deserialize_bytes<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a &[u8]. This allows deserializers that provide a custom byte vector serialization to properly deserialize the type.

fn deserialize_byte_buf<__V>(self,
                             visitor: __V)
                             -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a Vec<u8>. This allows deserializers that provide a custom byte vector serialization to properly deserialize the type and prevent needless intermediate allocations that would occur when going through &[u8].

fn deserialize_map<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a map of values. This allows deserializers to parse sequences that aren't tagged as maps.

fn deserialize_unit_struct<__V>(self,
                                _: &'static str,
                                visitor: __V)
                                -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a unit struct. This allows deserializers to a unit struct that aren't tagged as a unit struct.

fn deserialize_tuple_struct<__V>(self,
                                 _: &'static str,
                                 _: usize,
                                 visitor: __V)
                                 -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a tuple struct. This allows deserializers to parse sequences that aren't tagged as sequences.

fn deserialize_struct<__V>(self,
                           _: &'static str,
                           _: &'static [&'static str],
                           visitor: __V)
                           -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a struct. This allows deserializers to parse sequences that aren't tagged as maps.

fn deserialize_struct_field<__V>(self,
                                 visitor: __V)
                                 -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting some sort of struct field name. This allows deserializers to choose between &str, usize, or &[u8] to properly deserialize a struct field.

fn deserialize_tuple<__V>(self,
                          _: usize,
                          visitor: __V)
                          -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type is expecting a tuple value. This allows deserializers that provide a custom tuple serialization to properly deserialize the type.

fn deserialize_ignored_any<__V>(self,
                                visitor: __V)
                                -> Result<__V::Value, Self::Error> where __V: Visitor

This method hints that the Deserialize type needs to deserialize a value whose type doesn't matter because it is ignored.