Trait Observe

Source

pub trait Observe {
    type Observer<'ob, S, D>: Observer<Head = S, InnerDepth = D>
       where Self: 'ob,
             D: Unsigned,
             S: AsDerefMut<D, Target = Self> + ?Sized + 'ob;
    type Spec;
}

Expand description

A trait for types that can be observed for mutations.

Types implementing Observe can be wrapped in Observers that track mutations. The trait is typically derived using the #[derive(Observe)] macro and used in observe! macros.

A single type T may have many possible Observer<'ob, Target = T> implementations in theory, each with different change-tracking strategies. The Observe trait selects one of these as the default observer to be used by #[derive(Observe)] and other generic code that needs an observer for T.

When you #[derive(Observe)] on a struct, the macro requires that each field type implements Observe so it can select an appropriate default observer for that field. The Observer associated type of each field’s Observe implementation determines which observer will be instantiated in the generated code.

§Example

use morphix::adapter::Json;
use morphix::{Observe, observe};
use serde::Serialize;

#[derive(Serialize, Observe)]
struct MyStruct {
    field: String,
}

let mut data = MyStruct { field: "value".to_string() };
let Json(mutation) = observe!(data => {
    data.field.push_str(" modified");
}).unwrap();

Required Associated Types§

Source

type Observer<'ob, S, D>: Observer<Head = S, InnerDepth = D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

The default observer implementation for this type.

Source

type Spec

Marker type for selecting specialized observer implementations in wrapper types.

For most types, this will be DefaultSpec. Types can specify SnapshotSpec to enable snapshot-based observation strategies. For example, Option<T> uses OptionObserver when T::Spec = DefaultSpec, but SnapshotObserver when T::Spec = SnapshotSpec.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Trait Observe Copy item path

§Example

Required Associated Types§

type Observer<'ob, S, D>: Observer<Head = S, InnerDepth = D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec

Dyn Compatibility§

Implementations on Foreign Types§

impl Observe for IpAddr

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for SocketAddr

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for bool

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for char

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for f32

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for f64

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for i8

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for i16

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for i32

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for i64

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for i128

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for isize

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for str

type Observer<'ob, S, D> = StrObserver<'ob, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = DefaultSpec

impl Observe for u8

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for u16

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for u32

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for u64

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for u128

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for ()

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for usize

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for String

type Observer<'ob, S, D> = StringObserver<'ob, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = DefaultSpec

impl Observe for Arguments<'_>

type Observer<'ob, S, D> = GeneralObserver<'ob, PointerHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = DefaultSpec

impl Observe for Ipv4Addr

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for Ipv6Addr

type Observer<'ob, S, D> = GeneralObserver<'ob, SnapshotHandler<<S as AsDeref<D>>::Target>, S, D> where Self: 'ob, D: Unsigned, S: AsDerefMut<D, Target = Self> + ?Sized + 'ob

type Spec = SnapshotSpec

impl Observe for SocketAddrV4

Trait Observe