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Diffstat (limited to 'vendor/serde_json/src/value/mod.rs')
| -rw-r--r-- | vendor/serde_json/src/value/mod.rs | 1009 |
1 files changed, 0 insertions, 1009 deletions
diff --git a/vendor/serde_json/src/value/mod.rs b/vendor/serde_json/src/value/mod.rs deleted file mode 100644 index b3f51ea..0000000 --- a/vendor/serde_json/src/value/mod.rs +++ /dev/null @@ -1,1009 +0,0 @@ -//! The Value enum, a loosely typed way of representing any valid JSON value. -//! -//! # Constructing JSON -//! -//! Serde JSON provides a [`json!` macro][macro] to build `serde_json::Value` -//! objects with very natural JSON syntax. -//! -//! ``` -//! use serde_json::json; -//! -//! fn main() { -//! // The type of `john` is `serde_json::Value` -//! let john = json!({ -//! "name": "John Doe", -//! "age": 43, -//! "phones": [ -//! "+44 1234567", -//! "+44 2345678" -//! ] -//! }); -//! -//! println!("first phone number: {}", john["phones"][0]); -//! -//! // Convert to a string of JSON and print it out -//! println!("{}", john.to_string()); -//! } -//! ``` -//! -//! The `Value::to_string()` function converts a `serde_json::Value` into a -//! `String` of JSON text. -//! -//! One neat thing about the `json!` macro is that variables and expressions can -//! be interpolated directly into the JSON value as you are building it. Serde -//! will check at compile time that the value you are interpolating is able to -//! be represented as JSON. -//! -//! ``` -//! # use serde_json::json; -//! # -//! # fn random_phone() -> u16 { 0 } -//! # -//! let full_name = "John Doe"; -//! let age_last_year = 42; -//! -//! // The type of `john` is `serde_json::Value` -//! let john = json!({ -//! "name": full_name, -//! "age": age_last_year + 1, -//! "phones": [ -//! format!("+44 {}", random_phone()) -//! ] -//! }); -//! ``` -//! -//! A string of JSON data can be parsed into a `serde_json::Value` by the -//! [`serde_json::from_str`][from_str] function. There is also -//! [`from_slice`][from_slice] for parsing from a byte slice `&[u8]` and -//! [`from_reader`][from_reader] for parsing from any `io::Read` like a File or -//! a TCP stream. -//! -//! ``` -//! use serde_json::{json, Value, Error}; -//! -//! fn untyped_example() -> Result<(), Error> { -//! // Some JSON input data as a &str. Maybe this comes from the user. -//! let data = r#" -//! { -//! "name": "John Doe", -//! "age": 43, -//! "phones": [ -//! "+44 1234567", -//! "+44 2345678" -//! ] -//! }"#; -//! -//! // Parse the string of data into serde_json::Value. -//! let v: Value = serde_json::from_str(data)?; -//! -//! // Access parts of the data by indexing with square brackets. -//! println!("Please call {} at the number {}", v["name"], v["phones"][0]); -//! -//! Ok(()) -//! } -//! # -//! # untyped_example().unwrap(); -//! ``` -//! -//! [macro]: crate::json -//! [from_str]: crate::de::from_str -//! [from_slice]: crate::de::from_slice -//! [from_reader]: crate::de::from_reader - -use crate::error::Error; -use crate::io; -use alloc::string::String; -use alloc::vec::Vec; -use core::fmt::{self, Debug, Display}; -use core::mem; -use core::str; -use serde::de::DeserializeOwned; -use serde::ser::Serialize; - -pub use self::index::Index; -pub use self::ser::Serializer; -pub use crate::map::Map; -pub use crate::number::Number; - -#[cfg(feature = "raw_value")] -#[cfg_attr(docsrs, doc(cfg(feature = "raw_value")))] -pub use crate::raw::{to_raw_value, RawValue}; - -/// Represents any valid JSON value. -/// -/// See the [`serde_json::value` module documentation](self) for usage examples. -#[derive(Clone, Eq, PartialEq)] -pub enum Value { - /// Represents a JSON null value. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!(null); - /// ``` - Null, - - /// Represents a JSON boolean. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!(true); - /// ``` - Bool(bool), - - /// Represents a JSON number, whether integer or floating point. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!(12.5); - /// ``` - Number(Number), - - /// Represents a JSON string. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!("a string"); - /// ``` - String(String), - - /// Represents a JSON array. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!(["an", "array"]); - /// ``` - Array(Vec<Value>), - - /// Represents a JSON object. - /// - /// By default the map is backed by a BTreeMap. Enable the `preserve_order` - /// feature of serde_json to use IndexMap instead, which preserves - /// entries in the order they are inserted into the map. In particular, this - /// allows JSON data to be deserialized into a Value and serialized to a - /// string while retaining the order of map keys in the input. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "an": "object" }); - /// ``` - Object(Map<String, Value>), -} - -impl Debug for Value { - fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { - match self { - Value::Null => formatter.write_str("Null"), - Value::Bool(boolean) => write!(formatter, "Bool({})", boolean), - Value::Number(number) => Debug::fmt(number, formatter), - Value::String(string) => write!(formatter, "String({:?})", string), - Value::Array(vec) => { - tri!(formatter.write_str("Array ")); - Debug::fmt(vec, formatter) - } - Value::Object(map) => { - tri!(formatter.write_str("Object ")); - Debug::fmt(map, formatter) - } - } - } -} - -impl Display for Value { - /// Display a JSON value as a string. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let json = json!({ "city": "London", "street": "10 Downing Street" }); - /// - /// // Compact format: - /// // - /// // {"city":"London","street":"10 Downing Street"} - /// let compact = format!("{}", json); - /// assert_eq!(compact, - /// "{\"city\":\"London\",\"street\":\"10 Downing Street\"}"); - /// - /// // Pretty format: - /// // - /// // { - /// // "city": "London", - /// // "street": "10 Downing Street" - /// // } - /// let pretty = format!("{:#}", json); - /// assert_eq!(pretty, - /// "{\n \"city\": \"London\",\n \"street\": \"10 Downing Street\"\n}"); - /// ``` - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - struct WriterFormatter<'a, 'b: 'a> { - inner: &'a mut fmt::Formatter<'b>, - } - - impl<'a, 'b> io::Write for WriterFormatter<'a, 'b> { - fn write(&mut self, buf: &[u8]) -> io::Result<usize> { - // Safety: the serializer below only emits valid utf8 when using - // the default formatter. - let s = unsafe { str::from_utf8_unchecked(buf) }; - tri!(self.inner.write_str(s).map_err(io_error)); - Ok(buf.len()) - } - - fn flush(&mut self) -> io::Result<()> { - Ok(()) - } - } - - fn io_error(_: fmt::Error) -> io::Error { - // Error value does not matter because Display impl just maps it - // back to fmt::Error. - io::Error::new(io::ErrorKind::Other, "fmt error") - } - - let alternate = f.alternate(); - let mut wr = WriterFormatter { inner: f }; - if alternate { - // {:#} - super::ser::to_writer_pretty(&mut wr, self).map_err(|_| fmt::Error) - } else { - // {} - super::ser::to_writer(&mut wr, self).map_err(|_| fmt::Error) - } - } -} - -fn parse_index(s: &str) -> Option<usize> { - if s.starts_with('+') || (s.starts_with('0') && s.len() != 1) { - return None; - } - s.parse().ok() -} - -impl Value { - /// Index into a JSON array or map. A string index can be used to access a - /// value in a map, and a usize index can be used to access an element of an - /// array. - /// - /// Returns `None` if the type of `self` does not match the type of the - /// index, for example if the index is a string and `self` is an array or a - /// number. Also returns `None` if the given key does not exist in the map - /// or the given index is not within the bounds of the array. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let object = json!({ "A": 65, "B": 66, "C": 67 }); - /// assert_eq!(*object.get("A").unwrap(), json!(65)); - /// - /// let array = json!([ "A", "B", "C" ]); - /// assert_eq!(*array.get(2).unwrap(), json!("C")); - /// - /// assert_eq!(array.get("A"), None); - /// ``` - /// - /// Square brackets can also be used to index into a value in a more concise - /// way. This returns `Value::Null` in cases where `get` would have returned - /// `None`. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let object = json!({ - /// "A": ["a", "á", "à"], - /// "B": ["b", "b́"], - /// "C": ["c", "ć", "ć̣", "ḉ"], - /// }); - /// assert_eq!(object["B"][0], json!("b")); - /// - /// assert_eq!(object["D"], json!(null)); - /// assert_eq!(object[0]["x"]["y"]["z"], json!(null)); - /// ``` - pub fn get<I: Index>(&self, index: I) -> Option<&Value> { - index.index_into(self) - } - - /// Mutably index into a JSON array or map. A string index can be used to - /// access a value in a map, and a usize index can be used to access an - /// element of an array. - /// - /// Returns `None` if the type of `self` does not match the type of the - /// index, for example if the index is a string and `self` is an array or a - /// number. Also returns `None` if the given key does not exist in the map - /// or the given index is not within the bounds of the array. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let mut object = json!({ "A": 65, "B": 66, "C": 67 }); - /// *object.get_mut("A").unwrap() = json!(69); - /// - /// let mut array = json!([ "A", "B", "C" ]); - /// *array.get_mut(2).unwrap() = json!("D"); - /// ``` - pub fn get_mut<I: Index>(&mut self, index: I) -> Option<&mut Value> { - index.index_into_mut(self) - } - - /// Returns true if the `Value` is an Object. Returns false otherwise. - /// - /// For any Value on which `is_object` returns true, `as_object` and - /// `as_object_mut` are guaranteed to return the map representation of the - /// object. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let obj = json!({ "a": { "nested": true }, "b": ["an", "array"] }); - /// - /// assert!(obj.is_object()); - /// assert!(obj["a"].is_object()); - /// - /// // array, not an object - /// assert!(!obj["b"].is_object()); - /// ``` - pub fn is_object(&self) -> bool { - self.as_object().is_some() - } - - /// If the `Value` is an Object, returns the associated Map. Returns None - /// otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": { "nested": true }, "b": ["an", "array"] }); - /// - /// // The length of `{"nested": true}` is 1 entry. - /// assert_eq!(v["a"].as_object().unwrap().len(), 1); - /// - /// // The array `["an", "array"]` is not an object. - /// assert_eq!(v["b"].as_object(), None); - /// ``` - pub fn as_object(&self) -> Option<&Map<String, Value>> { - match self { - Value::Object(map) => Some(map), - _ => None, - } - } - - /// If the `Value` is an Object, returns the associated mutable Map. - /// Returns None otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let mut v = json!({ "a": { "nested": true } }); - /// - /// v["a"].as_object_mut().unwrap().clear(); - /// assert_eq!(v, json!({ "a": {} })); - /// ``` - pub fn as_object_mut(&mut self) -> Option<&mut Map<String, Value>> { - match self { - Value::Object(map) => Some(map), - _ => None, - } - } - - /// Returns true if the `Value` is an Array. Returns false otherwise. - /// - /// For any Value on which `is_array` returns true, `as_array` and - /// `as_array_mut` are guaranteed to return the vector representing the - /// array. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let obj = json!({ "a": ["an", "array"], "b": { "an": "object" } }); - /// - /// assert!(obj["a"].is_array()); - /// - /// // an object, not an array - /// assert!(!obj["b"].is_array()); - /// ``` - pub fn is_array(&self) -> bool { - self.as_array().is_some() - } - - /// If the `Value` is an Array, returns the associated vector. Returns None - /// otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": ["an", "array"], "b": { "an": "object" } }); - /// - /// // The length of `["an", "array"]` is 2 elements. - /// assert_eq!(v["a"].as_array().unwrap().len(), 2); - /// - /// // The object `{"an": "object"}` is not an array. - /// assert_eq!(v["b"].as_array(), None); - /// ``` - pub fn as_array(&self) -> Option<&Vec<Value>> { - match self { - Value::Array(array) => Some(array), - _ => None, - } - } - - /// If the `Value` is an Array, returns the associated mutable vector. - /// Returns None otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let mut v = json!({ "a": ["an", "array"] }); - /// - /// v["a"].as_array_mut().unwrap().clear(); - /// assert_eq!(v, json!({ "a": [] })); - /// ``` - pub fn as_array_mut(&mut self) -> Option<&mut Vec<Value>> { - match self { - Value::Array(list) => Some(list), - _ => None, - } - } - - /// Returns true if the `Value` is a String. Returns false otherwise. - /// - /// For any Value on which `is_string` returns true, `as_str` is guaranteed - /// to return the string slice. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": "some string", "b": false }); - /// - /// assert!(v["a"].is_string()); - /// - /// // The boolean `false` is not a string. - /// assert!(!v["b"].is_string()); - /// ``` - pub fn is_string(&self) -> bool { - self.as_str().is_some() - } - - /// If the `Value` is a String, returns the associated str. Returns None - /// otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": "some string", "b": false }); - /// - /// assert_eq!(v["a"].as_str(), Some("some string")); - /// - /// // The boolean `false` is not a string. - /// assert_eq!(v["b"].as_str(), None); - /// - /// // JSON values are printed in JSON representation, so strings are in quotes. - /// // - /// // The value is: "some string" - /// println!("The value is: {}", v["a"]); - /// - /// // Rust strings are printed without quotes. - /// // - /// // The value is: some string - /// println!("The value is: {}", v["a"].as_str().unwrap()); - /// ``` - pub fn as_str(&self) -> Option<&str> { - match self { - Value::String(s) => Some(s), - _ => None, - } - } - - /// Returns true if the `Value` is a Number. Returns false otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": 1, "b": "2" }); - /// - /// assert!(v["a"].is_number()); - /// - /// // The string `"2"` is a string, not a number. - /// assert!(!v["b"].is_number()); - /// ``` - pub fn is_number(&self) -> bool { - match *self { - Value::Number(_) => true, - _ => false, - } - } - - /// If the `Value` is a Number, returns the associated [`Number`]. Returns - /// None otherwise. - /// - /// ``` - /// # use serde_json::{json, Number}; - /// # - /// let v = json!({ "a": 1, "b": 2.2, "c": -3, "d": "4" }); - /// - /// assert_eq!(v["a"].as_number(), Some(&Number::from(1u64))); - /// assert_eq!(v["b"].as_number(), Some(&Number::from_f64(2.2).unwrap())); - /// assert_eq!(v["c"].as_number(), Some(&Number::from(-3i64))); - /// - /// // The string `"4"` is not a number. - /// assert_eq!(v["d"].as_number(), None); - /// ``` - pub fn as_number(&self) -> Option<&Number> { - match self { - Value::Number(number) => Some(number), - _ => None, - } - } - - /// 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. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let big = i64::max_value() as u64 + 10; - /// let v = json!({ "a": 64, "b": big, "c": 256.0 }); - /// - /// assert!(v["a"].is_i64()); - /// - /// // Greater than i64::MAX. - /// assert!(!v["b"].is_i64()); - /// - /// // Numbers with a decimal point are not considered integers. - /// assert!(!v["c"].is_i64()); - /// ``` - pub fn is_i64(&self) -> bool { - match self { - Value::Number(n) => n.is_i64(), - _ => false, - } - } - - /// Returns true if the `Value` is an integer between zero and `u64::MAX`. - /// - /// For any Value on which `is_u64` returns true, `as_u64` is guaranteed to - /// return the integer value. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": 64, "b": -64, "c": 256.0 }); - /// - /// assert!(v["a"].is_u64()); - /// - /// // Negative integer. - /// assert!(!v["b"].is_u64()); - /// - /// // Numbers with a decimal point are not considered integers. - /// assert!(!v["c"].is_u64()); - /// ``` - pub fn is_u64(&self) -> bool { - match self { - Value::Number(n) => n.is_u64(), - _ => false, - } - } - - /// Returns true if the `Value` is a number that can be represented by 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 but this is not a guarantee in the future. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": 256.0, "b": 64, "c": -64 }); - /// - /// assert!(v["a"].is_f64()); - /// - /// // Integers. - /// assert!(!v["b"].is_f64()); - /// assert!(!v["c"].is_f64()); - /// ``` - pub fn is_f64(&self) -> bool { - match self { - Value::Number(n) => n.is_f64(), - _ => false, - } - } - - /// If the `Value` is an integer, represent it as i64 if possible. Returns - /// None otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let big = i64::max_value() as u64 + 10; - /// let v = json!({ "a": 64, "b": big, "c": 256.0 }); - /// - /// assert_eq!(v["a"].as_i64(), Some(64)); - /// assert_eq!(v["b"].as_i64(), None); - /// assert_eq!(v["c"].as_i64(), None); - /// ``` - pub fn as_i64(&self) -> Option<i64> { - match self { - Value::Number(n) => n.as_i64(), - _ => None, - } - } - - /// If the `Value` is an integer, represent it as u64 if possible. Returns - /// None otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": 64, "b": -64, "c": 256.0 }); - /// - /// assert_eq!(v["a"].as_u64(), Some(64)); - /// assert_eq!(v["b"].as_u64(), None); - /// assert_eq!(v["c"].as_u64(), None); - /// ``` - pub fn as_u64(&self) -> Option<u64> { - match self { - Value::Number(n) => n.as_u64(), - _ => None, - } - } - - /// If the `Value` is a number, represent it as f64 if possible. Returns - /// None otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": 256.0, "b": 64, "c": -64 }); - /// - /// assert_eq!(v["a"].as_f64(), Some(256.0)); - /// assert_eq!(v["b"].as_f64(), Some(64.0)); - /// assert_eq!(v["c"].as_f64(), Some(-64.0)); - /// ``` - pub fn as_f64(&self) -> Option<f64> { - match self { - Value::Number(n) => n.as_f64(), - _ => None, - } - } - - /// Returns true if the `Value` is a Boolean. Returns false otherwise. - /// - /// For any Value on which `is_boolean` returns true, `as_bool` is - /// guaranteed to return the boolean value. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": false, "b": "false" }); - /// - /// assert!(v["a"].is_boolean()); - /// - /// // The string `"false"` is a string, not a boolean. - /// assert!(!v["b"].is_boolean()); - /// ``` - pub fn is_boolean(&self) -> bool { - self.as_bool().is_some() - } - - /// If the `Value` is a Boolean, returns the associated bool. Returns None - /// otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": false, "b": "false" }); - /// - /// assert_eq!(v["a"].as_bool(), Some(false)); - /// - /// // The string `"false"` is a string, not a boolean. - /// assert_eq!(v["b"].as_bool(), None); - /// ``` - pub fn as_bool(&self) -> Option<bool> { - match *self { - Value::Bool(b) => Some(b), - _ => None, - } - } - - /// Returns true if the `Value` is a Null. Returns false otherwise. - /// - /// For any Value on which `is_null` returns true, `as_null` is guaranteed - /// to return `Some(())`. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": null, "b": false }); - /// - /// assert!(v["a"].is_null()); - /// - /// // The boolean `false` is not null. - /// assert!(!v["b"].is_null()); - /// ``` - pub fn is_null(&self) -> bool { - self.as_null().is_some() - } - - /// If the `Value` is a Null, returns (). Returns None otherwise. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let v = json!({ "a": null, "b": false }); - /// - /// assert_eq!(v["a"].as_null(), Some(())); - /// - /// // The boolean `false` is not null. - /// assert_eq!(v["b"].as_null(), None); - /// ``` - pub fn as_null(&self) -> Option<()> { - match *self { - Value::Null => Some(()), - _ => None, - } - } - - /// 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](https://tools.ietf.org/html/rfc6901). - /// - /// # Examples - /// - /// ``` - /// # use serde_json::json; - /// # - /// let data = json!({ - /// "x": { - /// "y": ["z", "zz"] - /// } - /// }); - /// - /// assert_eq!(data.pointer("/x/y/1").unwrap(), &json!("zz")); - /// assert_eq!(data.pointer("/a/b/c"), None); - /// ``` - pub fn pointer(&self, pointer: &str) -> Option<&Value> { - if pointer.is_empty() { - return Some(self); - } - if !pointer.starts_with('/') { - return None; - } - pointer - .split('/') - .skip(1) - .map(|x| x.replace("~1", "/").replace("~0", "~")) - .try_fold(self, |target, token| match target { - Value::Object(map) => map.get(&token), - Value::Array(list) => parse_index(&token).and_then(|x| list.get(x)), - _ => None, - }) - } - - /// 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](https://tools.ietf.org/html/rfc6901). - /// - /// # Example of Use - /// - /// ``` - /// use serde_json::Value; - /// - /// 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())); - /// // Or change the value only if it exists - /// value.pointer_mut("/x").map(|v| *v = 1.5.into()); - /// - /// // "Steal" ownership of a value. Can replace with any valid Value. - /// let old_x = value.pointer_mut("/x").map(Value::take).unwrap(); - /// assert_eq!(old_x, 1.5); - /// assert_eq!(value.pointer("/x").unwrap(), &Value::Null); - /// } - /// ``` - pub fn pointer_mut(&mut self, pointer: &str) -> Option<&mut Value> { - if pointer.is_empty() { - return Some(self); - } - if !pointer.starts_with('/') { - return None; - } - pointer - .split('/') - .skip(1) - .map(|x| x.replace("~1", "/").replace("~0", "~")) - .try_fold(self, |target, token| match target { - Value::Object(map) => map.get_mut(&token), - Value::Array(list) => parse_index(&token).and_then(move |x| list.get_mut(x)), - _ => None, - }) - } - - /// Takes the value out of the `Value`, leaving a `Null` in its place. - /// - /// ``` - /// # use serde_json::json; - /// # - /// let mut v = json!({ "x": "y" }); - /// assert_eq!(v["x"].take(), json!("y")); - /// assert_eq!(v, json!({ "x": null })); - /// ``` - pub fn take(&mut self) -> Value { - mem::replace(self, Value::Null) - } -} - -/// The default value is `Value::Null`. -/// -/// This is useful for handling omitted `Value` fields when deserializing. -/// -/// # Examples -/// -/// ``` -/// # use serde::Deserialize; -/// use serde_json::Value; -/// -/// #[derive(Deserialize)] -/// struct Settings { -/// level: i32, -/// #[serde(default)] -/// extras: Value, -/// } -/// -/// # fn try_main() -> Result<(), serde_json::Error> { -/// let data = r#" { "level": 42 } "#; -/// let s: Settings = serde_json::from_str(data)?; -/// -/// assert_eq!(s.level, 42); -/// assert_eq!(s.extras, Value::Null); -/// # -/// # Ok(()) -/// # } -/// # -/// # try_main().unwrap() -/// ``` -impl Default for Value { - fn default() -> Value { - Value::Null - } -} - -mod de; -mod from; -mod index; -mod partial_eq; -mod ser; - -/// Convert a `T` into `serde_json::Value` which is an enum that can represent -/// any valid JSON data. -/// -/// # Example -/// -/// ``` -/// use serde::Serialize; -/// use serde_json::json; -/// use std::error::Error; -/// -/// #[derive(Serialize)] -/// struct User { -/// fingerprint: String, -/// location: String, -/// } -/// -/// fn compare_json_values() -> Result<(), Box<dyn Error>> { -/// let u = User { -/// fingerprint: "0xF9BA143B95FF6D82".to_owned(), -/// location: "Menlo Park, CA".to_owned(), -/// }; -/// -/// // The type of `expected` is `serde_json::Value` -/// let expected = json!({ -/// "fingerprint": "0xF9BA143B95FF6D82", -/// "location": "Menlo Park, CA", -/// }); -/// -/// let v = serde_json::to_value(u).unwrap(); -/// assert_eq!(v, expected); -/// -/// Ok(()) -/// } -/// # -/// # compare_json_values().unwrap(); -/// ``` -/// -/// # Errors -/// -/// This conversion can fail if `T`'s implementation of `Serialize` decides to -/// fail, or if `T` contains a map with non-string keys. -/// -/// ``` -/// use std::collections::BTreeMap; -/// -/// fn main() { -/// // The keys in this map are vectors, not strings. -/// let mut map = BTreeMap::new(); -/// map.insert(vec![32, 64], "x86"); -/// -/// println!("{}", serde_json::to_value(map).unwrap_err()); -/// } -/// ``` -// Taking by value is more friendly to iterator adapters, option and result -// consumers, etc. See https://github.com/serde-rs/json/pull/149. -pub fn to_value<T>(value: T) -> Result<Value, Error> -where - T: Serialize, -{ - value.serialize(Serializer) -} - -/// Interpret a `serde_json::Value` as an instance of type `T`. -/// -/// # Example -/// -/// ``` -/// use serde::Deserialize; -/// use serde_json::json; -/// -/// #[derive(Deserialize, Debug)] -/// struct User { -/// fingerprint: String, -/// location: String, -/// } -/// -/// fn main() { -/// // The type of `j` is `serde_json::Value` -/// let j = json!({ -/// "fingerprint": "0xF9BA143B95FF6D82", -/// "location": "Menlo Park, CA" -/// }); -/// -/// let u: User = serde_json::from_value(j).unwrap(); -/// println!("{:#?}", u); -/// } -/// ``` -/// -/// # Errors -/// -/// This conversion can fail if the structure of the Value does not match the -/// structure expected by `T`, for example if `T` is a struct type but the Value -/// contains something other than a JSON map. It can also fail if the structure -/// is correct but `T`'s implementation of `Deserialize` decides that something -/// is wrong with the data, for example required struct fields are missing from -/// the JSON map or some number is too big to fit in the expected primitive -/// type. -pub fn from_value<T>(value: Value) -> Result<T, Error> -where - T: DeserializeOwned, -{ - T::deserialize(value) -} |