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Diffstat (limited to 'vendor/serde_json/src/value/index.rs')
| -rw-r--r-- | vendor/serde_json/src/value/index.rs | 258 |
1 files changed, 0 insertions, 258 deletions
diff --git a/vendor/serde_json/src/value/index.rs b/vendor/serde_json/src/value/index.rs deleted file mode 100644 index 891ca8e..0000000 --- a/vendor/serde_json/src/value/index.rs +++ /dev/null @@ -1,258 +0,0 @@ -use super::Value; -use crate::map::Map; -use alloc::borrow::ToOwned; -use alloc::string::String; -use core::fmt::{self, Display}; -use core::ops; - -/// A type that can be used to index into a `serde_json::Value`. -/// -/// The [`get`] and [`get_mut`] methods of `Value` accept any type that -/// implements `Index`, as does the [square-bracket indexing operator]. This -/// trait is implemented for strings which are used as the index into a JSON -/// map, and for `usize` which is used as the index into a JSON array. -/// -/// [`get`]: ../enum.Value.html#method.get -/// [`get_mut`]: ../enum.Value.html#method.get_mut -/// [square-bracket indexing operator]: ../enum.Value.html#impl-Index%3CI%3E -/// -/// This trait is sealed and cannot be implemented for types outside of -/// `serde_json`. -/// -/// # Examples -/// -/// ``` -/// # use serde_json::json; -/// # -/// let data = json!({ "inner": [1, 2, 3] }); -/// -/// // Data is a JSON map so it can be indexed with a string. -/// let inner = &data["inner"]; -/// -/// // Inner is a JSON array so it can be indexed with an integer. -/// let first = &inner[0]; -/// -/// assert_eq!(first, 1); -/// ``` -pub trait Index: private::Sealed { - /// Return None if the key is not already in the array or object. - #[doc(hidden)] - fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value>; - - /// Return None if the key is not already in the array or object. - #[doc(hidden)] - fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value>; - - /// Panic if array index out of bounds. If key is not already in the object, - /// insert it with a value of null. Panic if Value is a type that cannot be - /// indexed into, except if Value is null then it can be treated as an empty - /// object. - #[doc(hidden)] - fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value; -} - -impl Index for usize { - fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value> { - match v { - Value::Array(vec) => vec.get(*self), - _ => None, - } - } - fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value> { - match v { - Value::Array(vec) => vec.get_mut(*self), - _ => None, - } - } - fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value { - match v { - Value::Array(vec) => { - let len = vec.len(); - vec.get_mut(*self).unwrap_or_else(|| { - panic!( - "cannot access index {} of JSON array of length {}", - self, len - ) - }) - } - _ => panic!("cannot access index {} of JSON {}", self, Type(v)), - } - } -} - -impl Index for str { - fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value> { - match v { - Value::Object(map) => map.get(self), - _ => None, - } - } - fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value> { - match v { - Value::Object(map) => map.get_mut(self), - _ => None, - } - } - fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value { - if let Value::Null = v { - *v = Value::Object(Map::new()); - } - match v { - Value::Object(map) => map.entry(self.to_owned()).or_insert(Value::Null), - _ => panic!("cannot access key {:?} in JSON {}", self, Type(v)), - } - } -} - -impl Index for String { - fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value> { - self[..].index_into(v) - } - fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value> { - self[..].index_into_mut(v) - } - fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value { - self[..].index_or_insert(v) - } -} - -impl<T> Index for &T -where - T: ?Sized + Index, -{ - fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value> { - (**self).index_into(v) - } - fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value> { - (**self).index_into_mut(v) - } - fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value { - (**self).index_or_insert(v) - } -} - -// Prevent users from implementing the Index trait. -mod private { - pub trait Sealed {} - impl Sealed for usize {} - impl Sealed for str {} - impl Sealed for alloc::string::String {} - impl<'a, T> Sealed for &'a T where T: ?Sized + Sealed {} -} - -/// Used in panic messages. -struct Type<'a>(&'a Value); - -impl<'a> Display for Type<'a> { - fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { - match *self.0 { - Value::Null => formatter.write_str("null"), - Value::Bool(_) => formatter.write_str("boolean"), - Value::Number(_) => formatter.write_str("number"), - Value::String(_) => formatter.write_str("string"), - Value::Array(_) => formatter.write_str("array"), - Value::Object(_) => formatter.write_str("object"), - } - } -} - -// The usual semantics of Index is to panic on invalid indexing. -// -// That said, the usual semantics are for things like Vec and BTreeMap which -// have different use cases than Value. If you are working with a Vec, you know -// that you are working with a Vec and you can get the len of the Vec and make -// sure your indices are within bounds. The Value use cases are more -// loosey-goosey. You got some JSON from an endpoint and you want to pull values -// out of it. Outside of this Index impl, you already have the option of using -// value.as_array() and working with the Vec directly, or matching on -// Value::Array and getting the Vec directly. The Index impl means you can skip -// that and index directly into the thing using a concise syntax. You don't have -// to check the type, you don't have to check the len, it is all about what you -// expect the Value to look like. -// -// Basically the use cases that would be well served by panicking here are -// better served by using one of the other approaches: get and get_mut, -// as_array, or match. The value of this impl is that it adds a way of working -// with Value that is not well served by the existing approaches: concise and -// careless and sometimes that is exactly what you want. -impl<I> ops::Index<I> for Value -where - I: Index, -{ - type Output = Value; - - /// Index into a `serde_json::Value` using the syntax `value[0]` or - /// `value["k"]`. - /// - /// Returns `Value::Null` 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 `Value::Null` if the given key does not exist - /// in the map or the given index is not within the bounds of the array. - /// - /// For retrieving deeply nested values, you should have a look at the - /// `Value::pointer` method. - /// - /// # Examples - /// - /// ``` - /// # use serde_json::json; - /// # - /// let data = json!({ - /// "x": { - /// "y": ["z", "zz"] - /// } - /// }); - /// - /// assert_eq!(data["x"]["y"], json!(["z", "zz"])); - /// assert_eq!(data["x"]["y"][0], json!("z")); - /// - /// assert_eq!(data["a"], json!(null)); // returns null for undefined values - /// assert_eq!(data["a"]["b"], json!(null)); // does not panic - /// ``` - fn index(&self, index: I) -> &Value { - static NULL: Value = Value::Null; - index.index_into(self).unwrap_or(&NULL) - } -} - -impl<I> ops::IndexMut<I> for Value -where - I: Index, -{ - /// Write into a `serde_json::Value` using the syntax `value[0] = ...` or - /// `value["k"] = ...`. - /// - /// If the index is a number, the value must be an array of length bigger - /// than the index. Indexing into a value that is not an array or an array - /// that is too small will panic. - /// - /// If the index is a string, the value must be an object or null which is - /// treated like an empty object. If the key is not already present in the - /// object, it will be inserted with a value of null. Indexing into a value - /// that is neither an object nor null will panic. - /// - /// # Examples - /// - /// ``` - /// # use serde_json::json; - /// # - /// let mut data = json!({ "x": 0 }); - /// - /// // replace an existing key - /// data["x"] = json!(1); - /// - /// // insert a new key - /// data["y"] = json!([false, false, false]); - /// - /// // replace an array value - /// data["y"][0] = json!(true); - /// - /// // inserted a deeply nested key - /// data["a"]["b"]["c"]["d"] = json!(true); - /// - /// println!("{}", data); - /// ``` - fn index_mut(&mut self, index: I) -> &mut Value { - index.index_or_insert(self) - } -} |