Struct alkahest::Lazy

pub struct Lazy<'de, F: ?Sized> { /* private fields */ }

Wrapper for lazy deserialization.

Lazy<F> deserializes data from formula F.

It can be used to deserialize value from formula F on demand. Also allows to deserialize that one value in place.

If generic parameter is slice (Lazy<[F]>) a lazy iterator can be obtained with Lazy::iter and Lazy::sized_iter(requires sized formula) methods.

If value is never needed, consider using Skip instead.

Implementations

impl<'de, F> Lazy<'de, F>where F: BareFormula + ?Sized,

pub fn get<T>(&self) -> Result<T, DeserializeError>where T: Deserialize<'de, F>,

Deserialize the lazy value.

Errors

Returns DeserializeError if deserialization fails.

pub fn get_in_place<T>(&self, place: &mut T) -> Result<(), DeserializeError>where T: Deserialize<'de, F> + ?Sized,

Deserialize the lazy value in place.

Errors

Returns DeserializeError if deserialization fails.

impl<'de, F> Lazy<'de, [F]>where F: Formula,

pub fn sized_iter<T>(&self) -> DeIter<'de, F, T, IterSized> where T: Deserialize<'de, F>,

Produce iterator over lazy deserialized values.

Example

let mut buffer = [0u8; 1024];

serialize::<[u32], _>([1u8, 2, 3], &mut buffer).unwrap();
let (lazy, _) = deserialize::<[u32], Lazy<[u32]>>(&buffer).unwrap();
let mut iter = lazy.sized_iter::<u32>();
assert_eq!(iter.next().unwrap().unwrap(), 1);
assert_eq!(iter.next().unwrap().unwrap(), 2);
assert_eq!(iter.next().unwrap().unwrap(), 3);
assert!(iter.next().is_none());

sized_iter cannot be used to deserialize slice of unsized formulas. Attempt to use unsized formula will result in compile error.

let mut buffer = [0u8; 1024];

serialize::<[As<str>], _>(["qwe", "rty"], &mut buffer).unwrap();
let (lazy, _) = deserialize::<[As<str>], Lazy<[As<str>]>>(&buffer).unwrap();
let mut iter = lazy.sized_iter::<&str>();
assert_eq!(iter.next().unwrap().unwrap(), "qwe");
assert_eq!(iter.next().unwrap().unwrap(), "rty");
assert!(iter.next().is_none());

pub fn iter<T>(&self) -> DeIter<'de, F, T> where T: Deserialize<'de, F>,

Produce iterator over lazy deserialized values.

Example

let mut buffer = [0u8; 1024];

serialize::<[u32], _>([1u8, 2, 3], &mut buffer).unwrap();
let (lazy, _) = deserialize::<[u32], Lazy<[u32]>>(&buffer).unwrap();
let mut iter = lazy.iter::<u32>();
assert_eq!(iter.next().unwrap().unwrap(), 1);
assert_eq!(iter.next().unwrap().unwrap(), 2);
assert_eq!(iter.next().unwrap().unwrap(), 3);
assert!(iter.next().is_none());

iter may be used to deserialize slice of unsized formulas.

let mut buffer = [0u8; 1024];

serialize::<[As<str>], _>(["qwe", "rty"], &mut buffer).unwrap();
let (seq, _) = deserialize::<[As<str>], Lazy<[As<str>]>>(&buffer).unwrap();
let mut iter = seq.iter::<&str>();
assert_eq!(iter.next().unwrap().unwrap(), "qwe");
assert_eq!(iter.next().unwrap().unwrap(), "rty");
assert!(iter.next().is_none());

Trait Implementations

impl<'de, F: Clone + ?Sized> Clone for Lazy<'de, F>

fn clone(&self) -> Lazy<'de, F>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'de, F> Debug for Lazy<'de, F>where F: ?Sized,

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

Formats the value using the given formatter.

impl<'de, 'fe: 'de, F> Deserialize<'fe, F> for Lazy<'de, F>where F: BareFormula + ?Sized,

fn deserialize(de: Deserializer<'fe>) -> Result<Self, DeserializeError>

Deserializes value provided deserializer. Returns deserialized value and the number of bytes consumed from the and of input.

fn deserialize_in_place( &mut self, de: Deserializer<'fe> ) -> Result<(), DeserializeError>

Deserializes value in-place provided deserializer. Overwrites self with data from the input.