Enum serde_yaml::Value [−][src]
pub enum Value { Null, Bool(bool), Number(Number), String(String), Sequence(Sequence), Mapping(Mapping), }
Expand description
Represents any valid YAML value.
Variants
Represents a YAML null value.
Bool(bool)
Represents a YAML boolean.
Number(Number)
Represents a YAML numerical value, whether integer or floating point.
String(String)
Represents a YAML string.
Sequence(Sequence)
Represents a YAML sequence in which the elements are
serde_yaml::Value
.
Mapping(Mapping)
Represents a YAML mapping in which the keys and values are both
serde_yaml::Value
.
Implementations
Index into a YAML sequence 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 sequence.
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 a sequence 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 sequence.
let object: Value = yaml(r#"{ A: 65, B: 66, C: 67 }"#); let x = object.get("A").unwrap(); assert_eq!(x, 65); let sequence: Value = yaml(r#"[ "A", "B", "C" ]"#); let x = sequence.get(2).unwrap(); assert_eq!(x, &Value::String("C".into())); assert_eq!(sequence.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
.
let object = yaml(r#" --- A: [a, á, à] B: [b, b́] C: [c, ć, ć̣, ḉ] 42: true "#); assert_eq!(object["B"][0], Value::String("b".into())); assert_eq!(object[Value::String("D".into())], Value::Null); assert_eq!(object["D"], Value::Null); assert_eq!(object[0]["x"]["y"]["z"], Value::Null); assert_eq!(object[42], Value::Bool(true));
Index into a YAML sequence 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 sequence.
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 a sequence 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 sequence.
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(())
.
let v: Value = serde_yaml::from_str("null").unwrap(); assert!(v.is_null());
let v: Value = serde_yaml::from_str("false").unwrap(); assert!(!v.is_null());
If the Value
is a Null, returns (). Returns None otherwise.
let v: Value = serde_yaml::from_str("null").unwrap(); assert_eq!(v.as_null(), Some(()));
let v: Value = serde_yaml::from_str("false").unwrap(); assert_eq!(v.as_null(), 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.
let v: Value = serde_yaml::from_str("true").unwrap(); assert!(v.is_bool());
let v: Value = serde_yaml::from_str("42").unwrap(); assert!(!v.is_bool());
If the Value
is a Boolean, returns the associated bool. Returns None
otherwise.
let v: Value = serde_yaml::from_str("true").unwrap(); assert_eq!(v.as_bool(), Some(true));
let v: Value = serde_yaml::from_str("42").unwrap(); assert_eq!(v.as_bool(), None);
Returns true if the Value
is a Number. Returns false otherwise.
let v: Value = serde_yaml::from_str("5").unwrap(); assert!(v.is_number());
let v: Value = serde_yaml::from_str("true").unwrap(); assert!(!v.is_number());
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.
let v: Value = serde_yaml::from_str("1337").unwrap(); assert!(v.is_i64());
let v: Value = serde_yaml::from_str("null").unwrap(); assert!(!v.is_i64());
If the Value
is an integer, represent it as i64 if possible. Returns
None otherwise.
let v: Value = serde_yaml::from_str("1337").unwrap(); assert_eq!(v.as_i64(), Some(1337));
let v: Value = serde_yaml::from_str("false").unwrap(); assert_eq!(v.as_i64(), None);
Returns true if the Value
is an integer between u64::MIN
and
u64::MAX
.
For any Value on which is_u64
returns true, as_u64
is guaranteed to
return the integer value.
let v: Value = serde_yaml::from_str("1337").unwrap(); assert!(v.is_u64());
let v: Value = serde_yaml::from_str("null").unwrap(); assert!(!v.is_u64());
If the Value
is an integer, represent it as u64 if possible. Returns
None otherwise.
let v: Value = serde_yaml::from_str("1337").unwrap(); assert_eq!(v.as_u64(), Some(1337));
let v: Value = serde_yaml::from_str("false").unwrap(); assert_eq!(v.as_u64(), None);
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.
let v: Value = serde_yaml::from_str("256.01").unwrap(); assert!(v.is_f64());
let v: Value = serde_yaml::from_str("true").unwrap(); assert!(!v.is_f64());
If the Value
is a number, represent it as f64 if possible. Returns
None otherwise.
let v: Value = serde_yaml::from_str("13.37").unwrap(); assert_eq!(v.as_f64(), Some(13.37));
let v: Value = serde_yaml::from_str("false").unwrap(); assert_eq!(v.as_f64(), 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.
let v: Value = serde_yaml::from_str("'lorem ipsum'").unwrap(); assert!(v.is_string());
let v: Value = serde_yaml::from_str("42").unwrap(); assert!(!v.is_string());
If the Value
is a String, returns the associated str. Returns None
otherwise.
let v: Value = serde_yaml::from_str("'lorem ipsum'").unwrap(); assert_eq!(v.as_str(), Some("lorem ipsum"));
let v: Value = serde_yaml::from_str("false").unwrap(); assert_eq!(v.as_str(), None);
Returns true if the Value
is a sequence. Returns false otherwise.
let v: Value = serde_yaml::from_str("[1, 2, 3]").unwrap(); assert!(v.is_sequence());
let v: Value = serde_yaml::from_str("true").unwrap(); assert!(!v.is_sequence());
If the Value
is a sequence, return a reference to it if possible.
Returns None otherwise.
let v: Value = serde_yaml::from_str("[1, 2]").unwrap(); assert_eq!(v.as_sequence(), Some(&vec![Value::Number(Number::from(1)), Value::Number(Number::from(2))]));
let v: Value = serde_yaml::from_str("false").unwrap(); assert_eq!(v.as_sequence(), None);
If the Value
is a sequence, return a mutable reference to it if
possible. Returns None otherwise.
let mut v: Value = serde_yaml::from_str("[1]").unwrap(); let s = v.as_sequence_mut().unwrap(); s.push(Value::Number(Number::from(2))); assert_eq!(s, &vec![Value::Number(Number::from(1)), Value::Number(Number::from(2))]);
let mut v: Value = serde_yaml::from_str("false").unwrap(); assert_eq!(v.as_sequence_mut(), None);
Returns true if the Value
is a mapping. Returns false otherwise.
let v: Value = serde_yaml::from_str("a: 42").unwrap(); assert!(v.is_mapping());
let v: Value = serde_yaml::from_str("true").unwrap(); assert!(!v.is_mapping());
If the Value
is a mapping, return a reference to it if possible.
Returns None otherwise.
let v: Value = serde_yaml::from_str("a: 42").unwrap(); let mut expected = Mapping::new(); expected.insert(Value::String("a".into()),Value::Number(Number::from(42))); assert_eq!(v.as_mapping(), Some(&expected));
let v: Value = serde_yaml::from_str("false").unwrap(); assert_eq!(v.as_mapping(), None);
If the Value
is a mapping, return a reference to it if possible.
Returns None otherwise.
let mut v: Value = serde_yaml::from_str("a: 42").unwrap(); let m = v.as_mapping_mut().unwrap(); m.insert(Value::String("b".into()), Value::Number(Number::from(21))); let mut expected = Mapping::new(); expected.insert(Value::String("a".into()), Value::Number(Number::from(42))); expected.insert(Value::String("b".into()), Value::Number(Number::from(21))); assert_eq!(m, &expected);
let mut v: Value = serde_yaml::from_str("false").unwrap(); assert_eq!(v.as_mapping_mut(), None);
Trait Implementations
The default value is Value::Null
.
This is useful for handling omitted Value
fields when deserializing.
Examples
use serde::Deserialize; use serde_yaml::Value; #[derive(Deserialize)] struct Settings { level: i32, #[serde(default)] extras: Value, } let data = r#" { "level": 42 } "#; let s: Settings = serde_yaml::from_str(data)?; assert_eq!(s.level, 42); assert_eq!(s.extras, Value::Null);
Deserialize this value from the given Serde deserializer. Read more
The error type that can be returned if some error occurs during deserialization. Read more
Require the Deserializer
to figure out how to drive the visitor based
on what data type is in the input. Read more
Hint that the Deserialize
type is expecting a bool
value.
Hint that the Deserialize
type is expecting an i8
value.
Hint that the Deserialize
type is expecting an i16
value.
Hint that the Deserialize
type is expecting an i32
value.
Hint that the Deserialize
type is expecting an i64
value.
Hint that the Deserialize
type is expecting an i128
value. Read more
Hint that the Deserialize
type is expecting a u8
value.
Hint that the Deserialize
type is expecting a u16
value.
Hint that the Deserialize
type is expecting a u32
value.
Hint that the Deserialize
type is expecting a u64
value.
Hint that the Deserialize
type is expecting an u128
value. Read more
Hint that the Deserialize
type is expecting a f32
value.
Hint that the Deserialize
type is expecting a f64
value.
Hint that the Deserialize
type is expecting a char
value.
Hint that the Deserialize
type is expecting a string value and does
not benefit from taking ownership of buffered data owned by the
Deserializer
. Read more
Hint that the Deserialize
type is expecting a string value and would
benefit from taking ownership of buffered data owned by the
Deserializer
. Read more
Hint that the Deserialize
type is expecting a byte array and does not
benefit from taking ownership of buffered data owned by the
Deserializer
. Read more
Hint that the Deserialize
type is expecting a byte array and would
benefit from taking ownership of buffered data owned by the
Deserializer
. Read more
Hint that the Deserialize
type is expecting an optional value. Read more
Hint that the Deserialize
type is expecting a unit value.
Hint that the Deserialize
type is expecting a unit struct with a
particular name. Read more
Hint that the Deserialize
type is expecting a newtype struct with a
particular name. Read more
Hint that the Deserialize
type is expecting a sequence of values.
Hint that the Deserialize
type is expecting a sequence of values and
knows how many values there are without looking at the serialized data. Read more
Hint that the Deserialize
type is expecting a tuple struct with a
particular name and number of fields. Read more
Hint that the Deserialize
type is expecting a map of key-value pairs.
fn deserialize_struct<V>(
self,
_name: &'static str,
_fields: &'static [&'static str],
visitor: V
) -> Result<V::Value, Error> where
V: Visitor<'de>,
fn deserialize_struct<V>(
self,
_name: &'static str,
_fields: &'static [&'static str],
visitor: V
) -> Result<V::Value, Error> where
V: Visitor<'de>,
Hint that the Deserialize
type is expecting a struct with a particular
name and fields. Read more
fn deserialize_enum<V>(
self,
_name: &str,
_variants: &'static [&'static str],
visitor: V
) -> Result<V::Value, Error> where
V: Visitor<'de>,
fn deserialize_enum<V>(
self,
_name: &str,
_variants: &'static [&'static str],
visitor: V
) -> Result<V::Value, Error> where
V: Visitor<'de>,
Hint that the Deserialize
type is expecting an enum value with a
particular name and possible variants. Read more
Hint that the Deserialize
type is expecting the name of a struct
field or the discriminant of an enum variant. Read more
Hint that the Deserialize
type needs to deserialize a value whose type
doesn’t matter because it is ignored. Read more
Determine whether Deserialize
implementations should expect to
deserialize their human-readable form. Read more
Convert copy-on-write string to Value
Examples
use serde_yaml::Value; use std::borrow::Cow; let s: Cow<str> = Cow::Borrowed("lorem"); let x: Value = s.into();
use serde_yaml::Value; use std::borrow::Cow; let s: Cow<str> = Cow::Owned("lorem".to_string()); let x: Value = s.into();
Convert an iteratable type to a YAML sequence
Examples
use serde_yaml::Value; let v = std::iter::repeat(42).take(5); let x: Value = v.collect();
use serde_yaml::Value; let v: Vec<_> = vec!["lorem", "ipsum", "dolor"]; let x: Value = v.into_iter().collect();
use std::iter::FromIterator; use serde_yaml::Value; let x: Value = Value::from_iter(vec!["lorem", "ipsum", "dolor"]);
Index into a serde_yaml::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 a sequence
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 sequence.
For retrieving deeply nested values, you should have a look at the
Value::pointer
method.
Examples
let data = yaml(r#"{ x: { y: [z, zz] } }"#); assert_eq!(data["x"]["y"], yaml(r#"["z", "zz"]"#)); assert_eq!(data["x"]["y"][0], yaml(r#""z""#)); assert_eq!(data["a"], yaml(r#"null"#)); // returns null for undefined values assert_eq!(data["a"]["b"], yaml(r#"null"#)); // does not panic
Write into a serde_yaml::Value
using the syntax value[0] = ...
or
value["k"] = ...
.
If the index is a number, the value must be a sequence of length bigger than the index. Indexing into a value that is not a sequence or a sequence 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
let mut data = yaml(r#"{x: 0}"#); // replace an existing key data["x"] = yaml(r#"1"#); // insert a new key data["y"] = yaml(r#"[false, false, false]"#); // replace a value in a sequence data["y"][0] = yaml(r#"true"#); // inserted a deeply nested key data["a"]["b"]["c"]["d"] = yaml(r#"true"#); println!("{:?}", data);
type Deserializer = Self
type Deserializer = Self
The type of the deserializer being converted into.
Convert this value into a deserializer.
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
Auto Trait Implementations
impl RefUnwindSafe for Value
impl UnwindSafe for Value
Blanket Implementations
Mutably borrows from an owned value. Read more