Repository: chancancode/rust-delegate
Branch: main
Commit: 8847e2333c93
Files: 33
Total size: 130.0 KB
Directory structure:
gitextract_6vrwi07n/
├── .github/
│ ├── FUNDING.yml
│ └── workflows/
│ ├── nightly-build.yml
│ ├── publish.yml
│ └── test.yml
├── .gitignore
├── .release-plz.toml
├── CHANGELOG.md
├── Cargo.toml
├── LICENSE-APACHE
├── LICENSE-MIT
├── README.md
├── src/
│ ├── attributes.rs
│ └── lib.rs
└── tests/
├── argument_modifier.rs
├── associated_const_delegation.rs
├── async_await.rs
├── closure.rs
├── delegate_to_enum.rs
├── delegation.rs
├── expand/
│ ├── fields.expanded.rs
│ └── fields.rs
├── expr.rs
├── expr_attribute.rs
├── fields.rs
├── function.rs
├── generic.rs
├── in_macro_expansion.rs
├── inline_args.rs
├── nested.rs
├── returntype.rs
├── segment_attributes.rs
├── stack.rs
└── through_trait.rs
================================================
FILE CONTENTS
================================================
================================================
FILE: .github/FUNDING.yml
================================================
github: Kobzol
================================================
FILE: .github/workflows/nightly-build.yml
================================================
on:
schedule:
- cron: "0 0 * * *"
workflow_dispatch:
name: Nightly Build
jobs:
test:
name: Build
runs-on: ubuntu-latest
strategy:
matrix:
rust:
- stable
- beta
- nightly
steps:
- name: Checkout sources
uses: actions/checkout@v2
- name: Install stable toolchain
uses: actions-rs/toolchain@v1
with:
profile: minimal
toolchain: ${{ matrix.rust }}
override: true
- name: Build
uses: actions-rs/cargo@v1
with:
command: build
args: --all --all-features
================================================
FILE: .github/workflows/publish.yml
================================================
name: Publish new release
on:
push:
branches:
- main
jobs:
test:
name: Release test
runs-on: ubuntu-latest
if: ${{ github.repository_owner == 'kobzol' }}
steps:
- &checkout
name: Checkout repository
uses: actions/checkout@v5
with:
fetch-depth: 0
persist-credentials: false
- &install-rust
name: Install Rust toolchain
uses: dtolnay/rust-toolchain@stable
- name: Install cargo-expand
uses: actions-rs/cargo@v1
with:
command: install
args: --locked --version 1.0.118 cargo-expand
- run: cargo test
# Release unpublished packages.
release:
name: Release-plz release
runs-on: ubuntu-latest
if: ${{ github.repository_owner == 'kobzol' }}
needs:
- test
permissions:
contents: write
id-token: write
steps:
- *checkout
- *install-rust
- name: Run release-plz
# 0.5.118
uses: release-plz/action@01df7609d1a7310c0776a102df00daf509d56e33
with:
command: release
env:
GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
# Create a PR with the new versions and changelog, preparing the next release.
create-release-pr:
name: Release-plz PR
runs-on: ubuntu-latest
if: ${{ github.repository_owner == 'kobzol' }}
permissions:
contents: write
pull-requests: write
concurrency:
group: release-plz-${{ github.ref }}
cancel-in-progress: false
steps:
- *checkout
- *install-rust
- name: Run release-plz
# 0.5.118
uses: release-plz/action@01df7609d1a7310c0776a102df00daf509d56e33
with:
command: release-pr
env:
GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
================================================
FILE: .github/workflows/test.yml
================================================
# Based on https://github.com/actions-rs/meta/blob/master/recipes/matrix.md
on: [ push, pull_request ]
name: Tests
jobs:
test:
name: Test
runs-on: ubuntu-latest
strategy:
matrix:
rust:
- stable
- beta
- nightly
steps:
- name: Checkout sources
uses: actions/checkout@v2
- name: Install stable toolchain
uses: actions-rs/toolchain@v1
with:
profile: minimal
toolchain: ${{ matrix.rust }}
override: true
components: rustfmt, clippy
- uses: Swatinem/rust-cache@v2
- name: Install cargo-expand
uses: actions-rs/cargo@v1
with:
command: install
args: --locked --version 1.0.118 cargo-expand
- name: Build
uses: actions-rs/cargo@v1
with:
command: build
args: --all --all-features
- name: Test
uses: actions-rs/cargo@v1
with:
command: test
- name: Lint
uses: actions-rs/cargo@v1
with:
command: clippy
args: -- -D warnings
- name: Formatting
uses: actions-rs/cargo@v1
with:
command: fmt
args: --all -- --check
================================================
FILE: .gitignore
================================================
/target
**/*.rs.bk
Cargo.lock
================================================
FILE: .release-plz.toml
================================================
[workspace]
release_always = false
pr_branch_prefix = "release-"
pr_labels = ["release"]
semver_check = false
================================================
FILE: CHANGELOG.md
================================================
# Changelog
All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
## [Unreleased]
## [0.13.5](https://github.com/Kobzol/rust-delegate/compare/v0.13.4...v0.13.5) - 2025-11-17
### New features
- Implement support for delegating to fields (#88 from JRRudy1).
### Internal
- Start using [release-plz](https://release-plz.dev/) for releases, together with crates.io Trusted Publishing.
# 0.13.4 (14. 7. 2025)
- Do not explicitly forward lifetime arguments when calling delegated functions (https://github.com/Kobzol/rust-delegate/issues/85).
# 0.13.3 (25. 3. 2025)
- Add `#[const(path::to::Trait::CONST)]` attribute to delegate associated constants via a getter (implemented by @vic1707).
- Add `#[expr(<$ template>)]` attribute to modify delegated call using custom code (implemented by @vic1707).
# 0.13.2 (14. 1. 2025)
- Correctly parse attributes with segmented paths (e.g. `#[a::b::c]`) (https://github.com/Kobzol/rust-delegate/issues/77).
# 0.13.1 (9. 10. 2024)
- Correctly pass generic method type and lifetime arguments to the delegated method.
# 0.13.0 (2. 9. 2024)
- Generalize match arms handling. You can now combine a match expression target with annotations like `#[into]` and
others:
```rust
struct A;
impl A {
pub fn callable(self) -> Self {
self
}
}
struct B;
impl B {
pub fn callable(self) -> Self {
self
}
}
enum Common {
A(A),
B(B),
}
impl From<A> for Common {
fn from(inner: A) -> Self {
Self::A(inner)
}
}
impl From<B> for Common {
fn from(inner: B) -> Self {
Self::B(inner)
}
}
impl Common {
delegate! {
to match self {
// ---------- `match` arms have incompatible types
Common::A(inner) => inner;
Common::B(inner) => inner;
} {
#[into]
pub fn callable(self) -> Self;
}
}
// Generates
// pub fn callable(self) -> Self {
// match self {
// Common::A(inner) => inner.callable().into(),
// Common::B(inner) => inner.callable().into(),
// }
// }
}
```
- The crate should be `#[no_std]` compatible again (https://github.com/Kobzol/rust-delegate/pull/74).
# 0.12.0 (22. 12. 2023)
- Add new `#[newtype]` function parameter modifier ([#64](https://github.com/Kobzol/rust-delegate/pull/64)).
Implemented by [Techassi](https://github.com/Techassi)
- Allow passing arbitrary attributes to delegation segments:
```rust
impl Foo {
delegate! {
#[inline(always)]
to self.0 { ... }
}
}
```
- Change the default inlining mode from `#[inline(always)]`
to `#[inline]` (https://github.com/Kobzol/rust-delegate/issues/61).
# 0.11.0 (4. 12. 2023)
- Allow delegating an associated function (not just a method).
```rust
struct A {}
impl A {
fn foo(a: u32) -> u32 {
a + 1
}
}
struct B;
impl B {
delegate! {
to A {
fn foo(a: u32) -> u32;
}
}
}
```
# 0.10.0 (29. 6. 2023)
- Allow specifying certain attributes (e.g. `#[into]` or `#[unwrap]`) on delegated segments.
The attribute will then be applied to all methods in that segment (unless it is overwritten on the method itself).
```rust
delegate! {
#[unwrap]
to self.inner {
fn foo(&self) -> u32; // calls self.inner.foo().unwrap()
fn bar(&self) -> u32; // calls self.inner.bar().unwrap()
}
}
```
- Add new `#[unwrap]` method modifier. Adding it on top of a delegated method will cause the generated
code to `.unwrap()` the result.
```rust
#[unwrap]
fn foo(&self) -> u32; // foo().unwrap()
```
- Add new `#[through(<trait>)]` method modifier. Adding it on top of a delegated method will cause the generated
code to call the method through the provided trait
using [UFCS](https://doc.rust-lang.org/reference/expressions/call-expr.html#disambiguating-function-calls).
```rust
#[through(MyTrait)]
delegate! {
to &self.inner {
#[through(MyTrait)]
fn foo(&self) -> u32; // MyTrait::foo(&self.inner)
}
}
```
- Removed `#[try_into(unwrap)]`. It can now be replaced with the combination of `#[try_into]` and `#[unwrap]`:
```rust
#[try_into]
#[unwrap]
fn foo(&self) -> u32; // TryInto::try_into(foo()).unwrap()
```
- Add the option to specify explicit type path to the `#[into]` expression modifier:
```rust
#[into(u64)]
fn foo(&self) -> u64; // Into::<u64>::into(foo())
```
- Expression modifiers `#[into]`, `#[try_into]` and `#[unwrap]` can now be used multiple times. The order
of their usage dictates in what order they will be applied:
```rust
#[into]
#[unwrap]
fn foo(&self) -> u32; // Into::into(foo()).unwrap()
#[unwrap]
#[into]
fn foo(&self) -> u32; // Into::into(foo().unwrap())
```
# 0.9.0 (16. 1. 2023)
- Add new `#[as_ref]` function parameter modifier ([#47](https://github.com/Kobzol/rust-delegate/pull/47)).
Implemented by [trueegorletov](https://github.com/trueegorletov).
# 0.8.0 (7. 9. 2022)
- Allow simple delegation to enum variants ([#45](https://github.com/Kobzol/rust-delegate/pull/45)).
Implemented by [gfreezy](https://github.com/gfreezy).
# 0.7.0 (6. 6. 2022)
- Add new `#[into]` attribute for delegated function parameters. If specified, the parameter will be
converted using the `From` trait before being passed as an argument to the called function.
- Add new `#[try_from]` attribute to delegated functions. You can use it to convert the delegated
expression using the `TryFrom` trait. You can also use `#[try_from(unwrap)]` to unwrap the result of
the conversion.
# 0.6.2 (31. 1. 2022)
- Add new `#[await(true/false)]` attribute to delegated functions. You can use it to control whether
`.await` will be appended to the delegated expression. It will be generated by default if the delegation
method signature is `async`.
# 0.6.1 (25. 7. 2021)
- add support for `async` functions. The delegated call will now use `.await`.
# 0.6.0 (7. 7. 2021)
- add the option to specify inline expressions that will be used as arguments for the delegated
call (https://github.com/kobzol/rust-delegate/pull/34)
- removed `append_args` attribute, which is superseded by the mentioned expression in signature support
# 0.5.2 (16. 6. 2021)
- add the `append_args` attribute to append attributes to delegated
calls (https://github.com/kobzol/rust-delegate/pull/31)
# 0.5.1 (6. 1. 2021)
- fix breaking change caused by using `syn` private API (https://github.com/kobzol/rust-delegate/issues/28)
# 0.5.0 (16. 11. 2020)
- `self` can now be used as the delegation target
- Rust 1.46 introduced a change that makes it a bit difficult to use `rust-delegate` implementations
generated by macros. If you have this use case, please
use [this workaround](https://github.com/kobzol/rust-delegate/issues/25#issuecomment-716774685).
================================================
FILE: Cargo.toml
================================================
[package]
name = "delegate"
description = "Method delegation with less boilerplate"
version = "0.13.5"
authors = ["Godfrey Chan <godfreykfc@gmail.com>", "Jakub Beránek <berykubik@gmail.com>"]
repository = "https://github.com/kobzol/rust-delegate"
readme = "README.md"
license = "MIT OR Apache-2.0"
edition = "2018"
include = [
"src/*.rs",
"Cargo.toml",
"README.md"
]
[dependencies]
syn = { version = "2", features = ["full", "visit-mut"] }
quote = "1"
proc-macro2 = "1"
[lib]
proc-macro = true
[dev-dependencies]
async-trait = "0.1.50"
futures = "0.3.16"
tokio = { version = "1.16.1", features = ["sync"] }
macrotest = "1.0.12"
================================================
FILE: LICENSE-APACHE
================================================
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================================================
FILE: LICENSE-MIT
================================================
Copyright (c) 2018 The Rust Delegate Crate Developers
Permission is hereby granted, free of charge, to any
person obtaining a copy of this software and associated
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================================================
FILE: README.md
================================================
# Method delegation with less boilerplate
[](https://github.com/kobzol/rust-delegate/actions)
[](https://crates.io/crates/delegate)
This crate removes some boilerplate for structs that simply delegate some of
their methods to one or more of their fields.
It gives you the `delegate!` macro, which delegates method calls to selected
expressions (usually inner fields).
## Example:
A Stack data structure implemented using an inner Vec via delegation.
```rust
use delegate::delegate;
#[derive(Clone, Debug)]
struct Stack<T> {
inner: Vec<T>,
}
impl<T> Stack<T> {
pub fn new() -> Self <T> {
Self { inner: vec![] }
}
delegate! {
to self.inner {
pub fn is_empty(&self) -> bool;
pub fn push(&mut self, value: T);
pub fn pop(&mut self) -> Option<T>;
pub fn clear(&mut self);
#[call(len)]
pub fn size(&self) -> usize;
#[call(last)]
pub fn peek(&self) -> Option<&T>;
}
}
}
```
## Features
### Delegate to a method with a different name
```rust
struct Stack {
inner: Vec<u32>
}
impl Stack {
delegate! {
to self.inner {
#[call(push)]
pub fn add(&mut self, value: u32);
}
}
}
```
### Use an arbitrary inner field expression
```rust
struct Wrapper {
inner: Rc<RefCell<Vec<u32>>>
}
impl Wrapper {
delegate! {
to self.inner.deref().borrow_mut() {
pub fn push(&mut self, val: u32);
}
}
}
```
### Delegate to enum variants
```rust
use delegate::delegate;
enum Enum {
A(A),
B(B),
C { v: C },
}
struct A {
val: usize,
}
impl A {
fn dbg_inner(&self) -> usize {
dbg!(self.val);
1
}
}
struct B {
val_a: String,
}
impl B {
fn dbg_inner(&self) -> usize {
dbg!(self.val_a.clone());
2
}
}
struct C {
val_c: f64,
}
impl C {
fn dbg_inner(&self) -> usize {
dbg!(self.val_c);
3
}
}
impl Enum {
delegate! {
// transformed to
//
// ```rust
// match self {
// Enum::A(a) => a.dbg_inner(),
// Enum::B(b) => { println!("i am b"); b }.dbg_inner(),
// Enum::C { v: c } => { c }.dbg_inner(),
// }
// ```
to match self {
Enum::A(a) => a,
Enum::B(b) => { println!("i am b"); b },
Enum::C { v: c } => { c },
} {
fn dbg_inner(&self) -> usize;
}
}
}
```
### Use modifiers that alter the generated method body
```rust
use delegate::delegate;
struct Inner;
impl Inner {
pub fn method(&self, num: u32) -> u32 { num }
pub fn method_res(&self, num: u32) -> Result<u32, ()> { Ok(num) }
}
struct Wrapper {
inner: Inner
}
impl Wrapper {
delegate! {
to self.inner {
// calls method, converts result to u64 using `From`
#[into]
pub fn method(&self, num: u32) -> u64;
// calls method, returns ()
#[call(method)]
pub fn method_noreturn(&self, num: u32);
// calls method, converts result to i6 using `TryFrom`
#[try_into]
#[call(method)]
pub fn method2(&self, num: u32) -> Result<u16, std::num::TryFromIntError>;
// calls method_res, unwraps the result
#[unwrap]
pub fn method_res(&self, num: u32) -> u32;
// calls method_res, unwraps the result, then calls into
#[unwrap]
#[into]
#[call(method_res)]
pub fn method_res_into(&self, num: u32) -> u64;
// specify explicit type for into
#[into(u64)]
#[call(method)]
pub fn method_into_explicit(&self, num: u32) -> u64;
}
}
}
```
### Custom called expression
The `#[expr()]` attribute can be used to modify the delegated call. You can use the `$` sigil as a placeholder for what delegate would normally expand to, and wrap that expression with custom code.
_Note:_ the `$` placeholder isn't required and can be present multiple times if you want.
```rust
struct A(Vec<u8>);
impl A {
delegate! {
to self.0 {
#[expr(*$.unwrap())]
/// Here `$` == `self.0.get(idx)`
/// Will expand to `*self.0.get(idx).unwrap()`
fn get(&self, idx: usize) -> u8;
#[call(get)]
#[expr($?.checked_pow(2))]
/// Here `$` == `self.0.get(idx)`
/// Will expand to `self.0.get(idx)?.checked_pow(2)`
fn get_checked_pow_2(&self, idx: usize) -> Option<u8>;
}
}
}
```
### Add additional arguments to method
```rust
struct Inner(u32);
impl Inner {
pub fn new(m: u32) -> Self {
// some "very complex" constructing work
Self(m)
}
pub fn method(&self, n: u32) -> u32 {
self.0 + n
}
}
struct Wrapper {
inner: OnceCell<Inner>,
}
impl Wrapper {
pub fn new() -> Self {
Self {
inner: OnceCell::new(),
}
}
fn content(&self, val: u32) -> &Inner {
self.inner.get_or_init(|| Inner(val))
}
delegate! {
to |k: u32| self.content(k) {
// `wrapper.method(k, num)` will call `self.content(k).method(num)`
pub fn method(&self, num: u32) -> u32;
}
}
}
```
### Call `await` on async functions
```rust
struct Inner;
impl Inner {
pub async fn method(&self, num: u32) -> u32 { num }
}
struct Wrapper {
inner: Inner
}
impl Wrapper {
delegate! {
to self.inner {
// calls method(num).await, returns impl Future<Output = u32>
pub async fn method(&self, num: u32) -> u32;
// calls method(num).await.into(), returns impl Future<Output = u64>
#[into]
#[call(method)]
pub async fn method_into(&self, num: u32) -> u64;
}
}
}
```
You can use the `#[await(true/false)]` attribute on delegated methods to specify
if `.await` should be generated after the delegated expression. It will be
generated by default if the delegated method is `async`.
### Delegate to multiple fields
```rust
struct MultiStack {
left: Vec<u32>,
right: Vec<u32>,
}
impl MultiStack {
delegate! {
to self.left {
/// Push an item to the top of the left stack
#[call(push)]
pub fn push_left(&mut self, value: u32);
}
to self.right {
/// Push an item to the top of the right stack
#[call(push)]
pub fn push_right(&mut self, value: u32);
}
}
}
```
### Inline attributes
`rust-delegate` inserts `#[inline(always)]` automatically. You can override that decision by specifying `#[inline]`
manually on the delegated method.
### Segment attributes
You can use an attribute on a whole delegation segment to automatically apply it to all methods in that segment:
```rust
struct Wrapper {
inner: Inner
}
impl Wrapper {
delegate! {
#[unwrap]
to self.inner {
fn foo(&self) -> u32; // calls self.inner.foo().unwrap()
fn bar(&self) -> u32; // calls self.inner.bar().unwrap()
}
}
}
```
### Adding additional arguments
You can specify expressions in the signature that will be used as delegated arguments:
```rust
use delegate::delegate;
struct Inner;
impl Inner {
pub fn polynomial(&self, a: i32, x: i32, b: i32, y: i32, c: i32) -> i32 {
a + x * x + b * y + c
}
}
struct Wrapper {
inner: Inner,
a: i32,
b: i32,
c: i32
}
impl Wrapper {
delegate! {
to self.inner {
// Calls `polynomial` on `inner` with `self.a`, `self.b` and
// `self.c` passed as arguments `a`, `b`, and `c`, effectively
// calling `polynomial(self.a, x, self.b, y, self.c)`.
pub fn polynomial(&self, [ self.a ], x: i32, [ self.b ], y: i32, [ self.c ]) -> i32 ;
// Calls `polynomial` on `inner` with `0`s passed for arguments
// `a` and `x`, and `self.b` and `self.c` for `b` and `c`,
// effectively calling `polynomial(0, 0, self.b, y, self.c)`.
#[call(polynomial)]
pub fn linear(&self, [ 0 ], [ 0 ], [ self.b ], y: i32, [ self.c ]) -> i32 ;
}
}
}
```
### Parameter modifiers
You can modify how will an input parameter be passed to the delegated method with parameter attribute modifiers. Currently, the following modifiers are supported:
- `#[into]`: Calls `.into()` on the parameter passed to the delegated method.
- `#[as_ref]`: Calls `.as_ref()` on the parameter passed to the delegated method.
- `#[newtype]`: Accesses the first tuple element (`.0`) of the parameter passed to the delegated method.
> Note that these modifiers might be removed in the future, try to use the more general `#[expr]` mechanism to achieve this functionality.
```rust
use delegate::delegate;
struct InnerType {}
impl InnerType {
fn foo(&self, other: Self) {}
}
impl From<Wrapper> for InnerType {
fn from(wrapper: Wrapper) -> Self {
wrapper.0
}
}
struct Wrapper(InnerType);
impl Wrapper {
delegate! {
to self.0 {
// Calls `self.0.foo(other.into());`
pub fn foo(&self, #[into] other: Self);
// Calls `self.0.bar(other.0);`
pub fn bar(&self, #[newtype] other: Self);
}
}
}
```
### Delegate associated functions
```rust
use delegate::delegate;
struct A {}
impl A {
fn foo(a: u32) -> u32 {
a + 1
}
}
struct B;
impl B {
delegate! {
to A {
fn foo(a: u32) -> u32;
}
}
}
assert_eq!(B::foo(1), 2);
```
### Delegate associated constants
```rust
use delegate::delegate;
trait WithConst {
const TOTO: u8;
}
struct A;
impl WithConst for A {
const TOTO: u8 = 1;
}
struct B;
impl WithConst for B {
const TOTO: u8 = 2;
}
struct C;
impl WithConst for C {
const TOTO: u8 = 2;
}
enum Enum {
A(A),
B(B),
C(C),
}
impl Enum {
delegate! {
to match self {
Self::A(a) => a,
Self::B(b) => b,
Self::C(c) => { println!("hello from c"); c },
} {
#[const(WithConst::TOTO)]
fn get_toto(&self) -> u8;
}
}
}
assert_eq!(Enum::A(A).get_toto(), <A as WithConst>::TOTO);
```
### Delegate to fields
```rust
use delegate::delegate;
struct Datum {
value: u32,
error: u32,
}
struct DatumWrapper(Datum);
impl DatumWrapper {
delegate! {
to self.0 {
/// Get the value of a nested field with the same name
#[field]
fn value(&self) -> u32;
/// Get the value of a nested field with a different name
#[field(value)]
fn renamed_value(&self) -> u32;
/// Get shared reference to a nested field
#[field(&value)]
fn value_ref(&self) -> &u32;
/// Get mutable reference to a nested field
#[field(&mut value)]
fn value_ref_mut(&mut self) -> &mut u32;
/// Get mutable reference to a nested field with the same name
#[field(&)]
fn error(&self) -> &u32;
}
}
}
```
## Development
This project uses a standard test suite for quality control, as well as a set of
"expansion" tests that utilize the `macrotest` crate to ensure the macro expands
as expected. PRs implementing new features should add both standard and expansion
tests where appropriate.
To add an expansion test, place a Rust source file in the `tests/expand/` directory
with methods demonstrating the new feature. Next, run `cargo test` to run the test
suite and generate a `*.expanded.rs` file in the same directory. Next, carefully
inspect the contents of the generated file to confirm that all methods expanded as
expected. Finally, commit both files to the git repository. Future test suite runs
will now include expanding the source file and comparing it to the expanded file.
## License
Licensed under either of
- Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
http://www.apache.org/licenses/LICENSE-2.0)
- MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
at your option.
## Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
dual licensed as above, without any additional terms or conditions.
## Conduct
Please follow the [Rust Code of Conduct]. For escalation or moderation issues
please contact the crate author(s) listed in [`Cargo.toml`](./Cargo.toml).
[Rust Code of Conduct]: https://www.rust-lang.org/conduct.html
================================================
FILE: src/attributes.rs
================================================
use proc_macro2::{Delimiter, TokenStream, TokenTree};
use quote::ToTokens;
use std::collections::VecDeque;
use std::ops::Not;
use syn::parse::ParseStream;
use syn::{Attribute, Error, Meta, Path, PathSegment, Token, TypePath};
pub struct CallMethodAttribute {
name: syn::Ident,
}
impl syn::parse::Parse for CallMethodAttribute {
fn parse(input: ParseStream) -> Result<Self, Error> {
Ok(CallMethodAttribute {
name: input.parse()?,
})
}
}
#[derive(Default, Clone)]
pub struct GetFieldAttribute {
reference: Option<(Token![&], Option<Token![mut]>)>,
member: Option<syn::Member>,
}
impl GetFieldAttribute {
pub fn reference_tokens(&self) -> Option<TokenStream> {
let (ref_, mut_) = self.reference.as_ref()?;
let mut tokens = ref_.to_token_stream();
mut_.to_tokens(&mut tokens);
Some(tokens)
}
}
impl syn::parse::Parse for GetFieldAttribute {
fn parse(input: ParseStream) -> Result<Self, Error> {
let mut reference = None;
if let Ok(ref_) = input.parse::<syn::Token![&]>() {
reference = Some((ref_, None));
}
if let Some((_, mut_)) = &mut reference {
*mut_ = input.parse::<syn::Token![mut]>().ok();
}
let member = input.is_empty().not().then(|| input.parse()).transpose()?;
Ok(GetFieldAttribute { reference, member })
}
}
struct GenerateAwaitAttribute {
literal: syn::LitBool,
}
impl syn::parse::Parse for GenerateAwaitAttribute {
fn parse(input: ParseStream) -> Result<Self, Error> {
Ok(GenerateAwaitAttribute {
literal: input.parse()?,
})
}
}
struct IntoAttribute {
type_path: Option<TypePath>,
}
impl syn::parse::Parse for IntoAttribute {
fn parse(input: ParseStream) -> Result<Self, Error> {
let type_path: TypePath = input.parse().map_err(|error| {
Error::new(
input.span(),
format!("{error}\nExpected type name, e.g. #[into(u32)]"),
)
})?;
Ok(IntoAttribute {
type_path: Some(type_path),
})
}
}
pub struct AssociatedConstant {
pub const_name: PathSegment,
pub trait_path: Path,
}
impl syn::parse::Parse for AssociatedConstant {
fn parse(input: ParseStream) -> Result<Self, Error> {
let mut path = input.parse::<syn::Path>().map_err(|error| {
Error::new(
input.span(),
format!(
"{error}\nExpected const path, e.g. #[const(path::to::MyTrait::CONST_NAME)]"
),
)
})?;
let const_name = path.segments.pop().ok_or_else(|| {
Error::new_spanned(
&path,
"Expected a path. e.g. #[const(path::to::MyTrait::CONST_NAME)]",
)
})?;
// poping a segment leads to trailing `::`
path.segments.pop_punct().ok_or_else(|| {
Error::new_spanned(
&path,
"Expected a multipart path. e.g. #[const(path::to::MyTrait::CONST_NAME)]",
)
})?;
Ok(Self {
const_name: const_name.into_value(),
trait_path: path,
})
}
}
#[derive(Clone)]
/// Represent the placeholder `$` found inside an expr attribute's template
pub struct ExprPlaceHolder;
impl syn::parse::Parse for ExprPlaceHolder {
fn parse(input: ParseStream) -> syn::Result<Self> {
input.parse::<syn::Token![$]>()?;
Ok(Self)
}
}
/// Kind of allowed placeholders in an `expr` attribute template
#[derive(Clone)]
enum Placeholder {
ExprPlaceholder(ExprPlaceHolder),
}
#[derive(Clone)]
/// Tokens found in the expr attribute's template
/// Token are either
/// - a replacable pattern (placeholder)
/// - a normal token
/// - a group containing a recursive representation of template tokens
enum TemplateToken {
Normal(TokenTree),
Placeholder(Placeholder),
Group(Delimiter, TemplateExpr),
}
impl TemplateToken {
/// Replace relevant placeholder tokens with the provided tokens
fn replace(&self, replacement: &TokenStream) -> TokenStream {
match self {
Self::Group(del, template) => {
let replaced_tokens = template
.tokens
.iter()
.map(|token| token.replace(replacement));
proc_macro2::Group::new(*del, quote::quote! { #(#replaced_tokens)* })
.to_token_stream()
}
Self::Normal(token_tree) => token_tree.to_token_stream(),
Self::Placeholder(_) => replacement.clone(),
}
}
}
#[derive(Clone)]
/// An expr attribute's template
pub struct TemplateExpr {
tokens: Vec<TemplateToken>,
}
impl syn::parse::Parse for TemplateExpr {
/// Parsing a template means storing the raw template while differenciating
/// placeholders and "normal" tokens
fn parse(input: ParseStream) -> syn::Result<Self> {
let mut tokens = Vec::new();
while !input.is_empty() {
if input.fork().parse::<ExprPlaceHolder>().is_ok() {
let placeholder = input.parse()?;
tokens.push(TemplateToken::Placeholder(Placeholder::ExprPlaceholder(
placeholder,
)));
continue;
}
match input.parse()? {
TokenTree::Group(group) => {
let inner_stream = group.stream();
let inner_expr = syn::parse2(inner_stream)?;
tokens.push(TemplateToken::Group(group.delimiter(), inner_expr));
}
other => {
tokens.push(TemplateToken::Normal(other));
}
}
}
Ok(TemplateExpr { tokens })
}
}
impl TemplateExpr {
/// returns the template after expanding the relevant placeholders
pub fn expand_template(&self, replacement: &TokenStream) -> TokenStream {
self.tokens.iter().fold(TokenStream::new(), |mut ts, tok| {
ts.extend(tok.replace(replacement));
ts
})
}
}
pub struct TraitTarget {
type_path: TypePath,
}
impl syn::parse::Parse for TraitTarget {
fn parse(input: ParseStream) -> Result<Self, Error> {
let type_path: TypePath = input.parse().map_err(|error| {
Error::new(
input.span(),
format!("{error}\nExpected trait path, e.g. #[through(foo::MyTrait)]"),
)
})?;
Ok(TraitTarget { type_path })
}
}
#[derive(Clone)]
pub enum ReturnExpression {
Into(Option<TypePath>),
TryInto,
Unwrap,
}
pub enum TargetSpecifier {
Field(GetFieldAttribute),
Method(CallMethodAttribute),
}
impl TargetSpecifier {
pub fn get_member(&self, default: &syn::Ident) -> syn::Member {
match self {
Self::Field(GetFieldAttribute {
member: Some(member),
..
}) => member.clone(),
Self::Field(_) => default.clone().into(),
Self::Method(method) => method.name.clone().into(),
}
}
}
enum ParsedAttribute {
ReturnExpression(ReturnExpression),
Await(bool),
TargetSpecifier(TargetSpecifier),
ThroughTrait(TraitTarget),
ConstantAccess(AssociatedConstant),
Expr(TemplateExpr),
}
fn parse_attributes(
attrs: &[Attribute],
) -> (
impl Iterator<Item = ParsedAttribute> + '_,
impl Iterator<Item = &Attribute>,
) {
let (parsed, other): (Vec<_>, Vec<_>) = attrs
.iter()
.map(|attribute| {
let parsed = if let syn::AttrStyle::Outer = attribute.style {
let name = attribute
.path()
.get_ident()
.map(|i| i.to_string())
.unwrap_or_default();
match name.as_str() {
"call" => {
let target = attribute
.parse_args::<CallMethodAttribute>()
.expect("Cannot parse `call` attribute");
let spec = TargetSpecifier::Method(target);
Some(ParsedAttribute::TargetSpecifier(spec))
}
"field" => {
let target = if let syn::Meta::Path(_) = &attribute.meta {
GetFieldAttribute::default()
} else {
attribute
.parse_args::<GetFieldAttribute>()
.expect("Cannot parse `field` attribute")
};
let spec = TargetSpecifier::Field(target);
Some(ParsedAttribute::TargetSpecifier(spec))
}
"into" => {
let into = match &attribute.meta {
Meta::NameValue(_) => {
panic!("Cannot parse `into` attribute: expected parentheses")
}
Meta::Path(_) => IntoAttribute { type_path: None },
Meta::List(meta) => meta
.parse_args::<IntoAttribute>()
.expect("Cannot parse `into` attribute"),
};
Some(ParsedAttribute::ReturnExpression(ReturnExpression::Into(
into.type_path,
)))
}
"try_into" => {
if let Meta::List(meta) = &attribute.meta {
meta.parse_nested_meta(|meta| {
if meta.path.is_ident("unwrap") {
panic!(
"Replace #[try_into(unwrap)] with\n#[try_into]\n#[unwrap]",
);
}
Ok(())
})
.expect("Invalid `try_into` arguments");
}
Some(ParsedAttribute::ReturnExpression(ReturnExpression::TryInto))
}
"unwrap" => Some(ParsedAttribute::ReturnExpression(ReturnExpression::Unwrap)),
"await" => {
let generate = attribute
.parse_args::<GenerateAwaitAttribute>()
.expect("Cannot parse `await` attribute");
Some(ParsedAttribute::Await(generate.literal.value))
}
"through" => Some(ParsedAttribute::ThroughTrait(
attribute
.parse_args::<TraitTarget>()
.expect("Cannot parse `through` attribute"),
)),
"const" => Some(ParsedAttribute::ConstantAccess(
attribute
.parse_args::<AssociatedConstant>()
.expect("Cannot parse `const` attribute"),
)),
"expr" => Some(ParsedAttribute::Expr(
attribute
.parse_args::<TemplateExpr>()
.expect("Cannot parse `expr` attribute"),
)),
_ => None,
}
} else {
None
};
(parsed, attribute)
})
.partition(|(parsed, _)| parsed.is_some());
(
parsed.into_iter().map(|(parsed, _)| parsed.unwrap()),
other.into_iter().map(|(_, attr)| attr),
)
}
pub struct MethodAttributes<'a> {
pub attributes: Vec<&'a Attribute>,
pub target_specifier: Option<TargetSpecifier>,
pub expressions: VecDeque<ReturnExpression>,
pub generate_await: Option<bool>,
pub target_trait: Option<TypePath>,
pub associated_constant: Option<AssociatedConstant>,
pub expr_attr: Option<TemplateExpr>,
}
/// Iterates through the attributes of a method and filters special attributes.
/// - call => sets the name of the target method to call
/// - into => generates a `into()` call after the delegated expression
/// - try_into => generates a `try_into()` call after the delegated expression
/// - await => generates an `.await` expression after the delegated expression
/// - unwrap => generates a `unwrap()` call after the delegated expression
/// - through => generates a UFCS call (`Target::method(&<expr>, ...)`) around the delegated expression
/// - const => generates a getter to a trait associated constant
pub fn parse_method_attributes<'a>(
attrs: &'a [Attribute],
method: &syn::TraitItemFn,
) -> MethodAttributes<'a> {
let mut target_spec: Option<TargetSpecifier> = None;
let mut expressions: Vec<ReturnExpression> = vec![];
let mut generate_await: Option<bool> = None;
let mut target_trait: Option<TraitTarget> = None;
let mut associated_constant: Option<AssociatedConstant> = None;
let mut expr_attr: Option<TemplateExpr> = None;
let (parsed, other) = parse_attributes(attrs);
for attr in parsed {
match attr {
ParsedAttribute::ReturnExpression(expr) => expressions.push(expr),
ParsedAttribute::Await(value) => {
if generate_await.is_some() {
panic!(
"Multiple `await` attributes specified for {}",
method.sig.ident
)
}
generate_await = Some(value);
}
ParsedAttribute::TargetSpecifier(spec) => {
if target_spec.is_some() {
panic!(
"Multiple field/call attributes specified for {}",
method.sig.ident
)
}
target_spec = Some(spec);
}
ParsedAttribute::ThroughTrait(target) => {
if target_trait.is_some() {
panic!(
"Multiple through attributes specified for {}",
method.sig.ident
)
}
target_trait = Some(target);
}
ParsedAttribute::ConstantAccess(const_attr) => {
if associated_constant.is_some() {
panic!(
"Multiple const attributes specified for {}",
method.sig.ident
)
}
associated_constant = Some(const_attr);
}
ParsedAttribute::Expr(token_tree) => {
if expr_attr.is_some() {
panic!(
"Multiple expr attributes specified for {}",
method.sig.ident
)
}
expr_attr = Some(token_tree);
}
}
}
if associated_constant.is_some() && target_spec.is_some() {
panic!("Cannot use both `call`/`field` and `const` attributes.");
}
MethodAttributes {
attributes: other.into_iter().collect(),
target_specifier: target_spec,
generate_await,
expressions: expressions.into(),
target_trait: target_trait.map(|t| t.type_path),
associated_constant,
expr_attr,
}
}
pub struct SegmentAttributes {
pub expressions: Vec<ReturnExpression>,
pub generate_await: Option<bool>,
pub target_trait: Option<TypePath>,
pub other_attrs: Vec<Attribute>,
pub expr_attr: Option<TemplateExpr>,
}
pub fn parse_segment_attributes(attrs: &[Attribute]) -> SegmentAttributes {
let mut expressions: Vec<ReturnExpression> = vec![];
let mut generate_await: Option<bool> = None;
let mut target_trait: Option<TraitTarget> = None;
let mut expr_attr: Option<TemplateExpr> = None;
let (parsed, other) = parse_attributes(attrs);
for attribute in parsed {
match attribute {
ParsedAttribute::ReturnExpression(expr) => expressions.push(expr),
ParsedAttribute::Await(value) => {
if generate_await.is_some() {
panic!("Multiple `await` attributes specified for segment");
}
generate_await = Some(value);
}
ParsedAttribute::ThroughTrait(target) => {
if target_trait.is_some() {
panic!("Multiple `through` attributes specified for segment");
}
target_trait = Some(target);
}
ParsedAttribute::TargetSpecifier(_) => {
panic!("Field/call attribute cannot be specified on a `to <expr>` segment.");
}
ParsedAttribute::ConstantAccess(_) => {
panic!("Const attribute cannot be specified on a `to <expr>` segment.");
}
ParsedAttribute::Expr(token_tree) => {
if expr_attr.is_some() {
panic!("Multiple `expr` attributes specified for segment");
}
expr_attr = Some(token_tree);
}
}
}
SegmentAttributes {
expressions,
generate_await,
target_trait: target_trait.map(|t| t.type_path),
other_attrs: other.cloned().collect::<Vec<_>>(),
expr_attr,
}
}
/// Applies default values from the segment and adds them to the method attributes.
pub fn combine_attributes<'a>(
mut method_attrs: MethodAttributes<'a>,
segment_attrs: &'a SegmentAttributes,
) -> MethodAttributes<'a> {
let SegmentAttributes {
expressions,
generate_await,
target_trait,
other_attrs,
expr_attr,
} = segment_attrs;
if method_attrs.generate_await.is_none() {
method_attrs.generate_await = *generate_await;
}
if method_attrs.target_trait.is_none() {
method_attrs.target_trait.clone_from(target_trait);
}
if method_attrs.expr_attr.is_none() {
method_attrs.expr_attr.clone_from(expr_attr);
}
for expr in expressions {
match expr {
ReturnExpression::Into(path) => {
if !method_attrs
.expressions
.iter()
.any(|expr| matches!(expr, ReturnExpression::Into(_)))
{
method_attrs
.expressions
.push_front(ReturnExpression::Into(path.clone()));
}
}
_ => method_attrs.expressions.push_front(expr.clone()),
}
}
for other_attr in other_attrs {
if !method_attrs
.attributes
.iter()
.any(|attr| attr.path().get_ident() == other_attr.path().get_ident())
{
method_attrs.attributes.push(other_attr);
}
}
method_attrs
}
================================================
FILE: src/lib.rs
================================================
//! This crate removes some boilerplate for structs that simply delegate
//! some of their methods to one or more of their fields.
//!
//! It gives you the `delegate!` macro, which delegates method calls to selected expressions (usually inner fields).
//!
//! ## Features:
//! - Delegate to a method with a different name
//! ```rust
//! use delegate::delegate;
//!
//! struct Stack { inner: Vec<u32> }
//! impl Stack {
//! delegate! {
//! to self.inner {
//! #[call(push)]
//! pub fn add(&mut self, value: u32);
//! }
//! }
//! }
//! ```
//! - Use an arbitrary inner field expression
//! ```rust
//! use delegate::delegate;
//!
//! use std::rc::Rc;
//! use std::cell::RefCell;
//! use std::ops::Deref;
//!
//! struct Wrapper { inner: Rc<RefCell<Vec<u32>>> }
//! impl Wrapper {
//! delegate! {
//! to self.inner.deref().borrow_mut() {
//! pub fn push(&mut self, val: u32);
//! }
//! }
//! }
//! ```
//!
//! - Delegate to enum variants
//!
//! ```rust
//! use delegate::delegate;
//!
//! enum Enum {
//! A(A),
//! B(B),
//! C { v: C },
//! }
//!
//! struct A {
//! val: usize,
//! }
//!
//! impl A {
//! fn dbg_inner(&self) -> usize {
//! dbg!(self.val);
//! 1
//! }
//! }
//! struct B {
//! val_a: String,
//! }
//!
//! impl B {
//! fn dbg_inner(&self) -> usize {
//! dbg!(self.val_a.clone());
//! 2
//! }
//! }
//!
//! struct C {
//! val_c: f64,
//! }
//!
//! impl C {
//! fn dbg_inner(&self) -> usize {
//! dbg!(self.val_c);
//! 3
//! }
//! }
//!
//! impl Enum {
//! delegate! {
//! // transformed to
//! //
//! // ```rust
//! // match self {
//! // Enum::A(a) => a.dbg_inner(),
//! // Enum::B(b) => { println!("i am b"); b }.dbg_inner(),
//! // Enum::C { v: c } => { c }.dbg_inner(),
//! // }
//! // ```
//! to match self {
//! Enum::A(a) => a,
//! Enum::B(b) => { println!("i am b"); b },
//! Enum::C { v: c } => { c },
//! } {
//! fn dbg_inner(&self) -> usize;
//! }
//! }
//! }
//! ```
//!
//! - Use modifiers that alter the generated method body
//! ```rust
//! use delegate::delegate;
//! struct Inner;
//! impl Inner {
//! pub fn method(&self, num: u32) -> u32 { num }
//! pub fn method_res(&self, num: u32) -> Result<u32, ()> { Ok(num) }
//! }
//! struct Wrapper { inner: Inner }
//! impl Wrapper {
//! delegate! {
//! to self.inner {
//! // calls method, converts result to u64 using `From`
//! #[into]
//! pub fn method(&self, num: u32) -> u64;
//!
//! // calls method, returns ()
//! #[call(method)]
//! pub fn method_noreturn(&self, num: u32);
//!
//! // calls method, converts result to i6 using `TryFrom`
//! #[try_into]
//! #[call(method)]
//! pub fn method2(&self, num: u32) -> Result<u16, std::num::TryFromIntError>;
//!
//! // calls method_res, unwraps the result
//! #[unwrap]
//! pub fn method_res(&self, num: u32) -> u32;
//!
//! // calls method_res, unwraps the result, then calls into
//! #[unwrap]
//! #[into]
//! #[call(method_res)]
//! pub fn method_res_into(&self, num: u32) -> u64;
//!
//! // specify explicit type for into
//! #[into(u64)]
//! #[call(method)]
//! pub fn method_into_explicit(&self, num: u32) -> u64;
//! }
//! }
//! }
//! ```
//!
//! - Custom called expression
//!
//! The `#[expr()]` attribute can be used to modify the delegated call. You can use the `$` sigil as a placeholder for what delegate would normally expand to, and wrap that expression with custom code.
//!
//! _Note:_ the `$` placeholder isn't required and can be present multiple times if you want.
//!
//! ```rs
//! struct A(Vec<u8>);
//!
//! impl A {
//! delegate! {
//! to self.0 {
//! #[expr(*$.unwrap())]
//! /// Here `$` == `self.0.get(idx)`
//! /// Will expand to `*self.0.get(idx).unwrap()`
//! fn get(&self, idx: usize) -> u8;
//!
//! #[call(get)]
//! #[expr($?.checked_pow(2))]
//! /// Here `$` == `self.0.get(idx)`
//! /// Will expand to `self.0.get(idx)?.checked_pow(2)`
//! fn get_checked_pow_2(&self, idx: usize) -> Option<u8>;
//! }
//! }
//! }
//! ```
//!
//! - Call `await` on async functions
//! ```rust
//! use delegate::delegate;
//!
//! struct Inner;
//! impl Inner {
//! pub async fn method(&self, num: u32) -> u32 { num }
//! }
//! struct Wrapper { inner: Inner }
//! impl Wrapper {
//! delegate! {
//! to self.inner {
//! // calls method(num).await, returns impl Future<Output = u32>
//! pub async fn method(&self, num: u32) -> u32;
//!
//! // calls method(num).await.into(), returns impl Future<Output = u64>
//! #[into]
//! #[call(method)]
//! pub async fn method_into(&self, num: u32) -> u64;
//! }
//! }
//! }
//! ```
//! You can use the `#[await(true/false)]` attribute on delegated methods to specify if `.await` should
//! be generated after the delegated expression. It will be generated by default if the delegated
//! method is `async`.
//! - Delegate to multiple fields
//! ```rust
//! use delegate::delegate;
//!
//! struct MultiStack {
//! left: Vec<u32>,
//! right: Vec<u32>,
//! }
//! impl MultiStack {
//! delegate! {
//! to self.left {
//! // Push an item to the top of the left stack
//! #[call(push)]
//! pub fn push_left(&mut self, value: u32);
//! }
//! to self.right {
//! // Push an item to the top of the right stack
//! #[call(push)]
//! pub fn push_right(&mut self, value: u32);
//! }
//! }
//! }
//! ```
//! - Inserts `#[inline(always)]` automatically (unless you specify `#[inline]` manually on the method)
//! - You can use an attribute on a whole segment to automatically apply it to all methods in that
//! segment:
//! ```rust
//! use delegate::delegate;
//!
//! struct Inner;
//!
//! impl Inner {
//! fn foo(&self) -> Result<u32, ()> { Ok(0) }
//! fn bar(&self) -> Result<u32, ()> { Ok(1) }
//! }
//!
//! struct Wrapper { inner: Inner }
//!
//! impl Wrapper {
//! delegate! {
//! #[unwrap]
//! to self.inner {
//! fn foo(&self) -> u32; // calls self.inner.foo().unwrap()
//! fn bar(&self) -> u32; // calls self.inner.bar().unwrap()
//! }
//! }
//! }
//! ```
//! - Specify expressions in the signature that will be used as delegated arguments
//! ```rust
//! use delegate::delegate;
//! struct Inner;
//! impl Inner {
//! pub fn polynomial(&self, a: i32, x: i32, b: i32, y: i32, c: i32) -> i32 {
//! a + x * x + b * y + c
//! }
//! }
//! struct Wrapper { inner: Inner, a: i32, b: i32, c: i32 }
//! impl Wrapper {
//! delegate! {
//! to self.inner {
//! // Calls `polynomial` on `inner` with `self.a`, `self.b` and
//! // `self.c` passed as arguments `a`, `b`, and `c`, effectively
//! // calling `polynomial(self.a, x, self.b, y, self.c)`.
//! pub fn polynomial(&self, [ self.a ], x: i32, [ self.b ], y: i32, [ self.c ]) -> i32 ;
//! // Calls `polynomial` on `inner` with `0`s passed for arguments
//! // `a` and `x`, and `self.b` and `self.c` for `b` and `c`,
//! // effectively calling `polynomial(0, 0, self.b, y, self.c)`.
//! #[call(polynomial)]
//! pub fn linear(&self, [ 0 ], [ 0 ], [ self.b ], y: i32, [ self.c ]) -> i32 ;
//! }
//! }
//! }
//! ```
//! - Modify how will an input parameter be passed to the delegated method with parameter attribute modifiers.
//! Currently, the following modifiers are supported:
//! - `#[into]`: Calls `.into()` on the parameter passed to the delegated method.
//! - `#[as_ref]`: Calls `.as_ref()` on the parameter passed to the delegated method.
//! - `#[newtype]`: Calls `.0` on the parameter passed to the delegated method.
//! ```rust
//! use delegate::delegate;
//!
//! struct InnerType {}
//! impl InnerType {
//! fn foo(&self, other: Self) {}
//! }
//!
//! impl From<Wrapper> for InnerType {
//! fn from(wrapper: Wrapper) -> Self {
//! wrapper.0
//! }
//! }
//!
//! struct Wrapper(InnerType);
//! impl Wrapper {
//! delegate! {
//! to self.0 {
//! // Calls `self.0.foo(other.into());`
//! pub fn foo(&self, #[into] other: Self);
//! }
//! }
//! }
//! ```
//! - Specify a trait through which will the delegated method be called
//! (using [UFCS](https://doc.rust-lang.org/reference/expressions/call-expr.html#disambiguating-function-calls).
//! ```rust
//! use delegate::delegate;
//!
//! struct InnerType {}
//! impl InnerType {
//!
//! }
//!
//! trait MyTrait {
//! fn foo(&self);
//! }
//! impl MyTrait for InnerType {
//! fn foo(&self) {}
//! }
//!
//! struct Wrapper(InnerType);
//! impl Wrapper {
//! delegate! {
//! to &self.0 {
//! // Calls `MyTrait::foo(&self.0)`
//! #[through(MyTrait)]
//! pub fn foo(&self);
//! }
//! }
//! }
//! ```
//!
//! - Add additional arguments to method
//!
//! ```rust
//! use delegate::delegate;
//! use std::cell::OnceCell;
//! struct Inner(u32);
//! impl Inner {
//! pub fn new(m: u32) -> Self {
//! // some "very complex" constructing work
//! Self(m)
//! }
//! pub fn method(&self, n: u32) -> u32 {
//! self.0 + n
//! }
//! }
//!
//! struct Wrapper {
//! inner: OnceCell<Inner>,
//! }
//!
//! impl Wrapper {
//! pub fn new() -> Self {
//! Self {
//! inner: OnceCell::new(),
//! }
//! }
//! fn content(&self, val: u32) -> &Inner {
//! self.inner.get_or_init(|| Inner(val))
//! }
//! delegate! {
//! to |k: u32| self.content(k) {
//! // `wrapper.method(k, num)` will call `self.content(k).method(num)`
//! pub fn method(&self, num: u32) -> u32;
//! }
//! }
//! }
//! ```
//! - Delegate associated functions
//! ```rust
//! use delegate::delegate;
//!
//! struct A {}
//! impl A {
//! fn foo(a: u32) -> u32 {
//! a + 1
//! }
//! }
//!
//! struct B;
//!
//! impl B {
//! delegate! {
//! to A {
//! fn foo(a: u32) -> u32;
//! }
//! }
//! }
//!
//! assert_eq!(B::foo(1), 2);
//! ```
//! - Delegate associated constants
//!
//! ```rust
//! use delegate::delegate;
//!
//! trait WithConst {
//! const TOTO: u8;
//! }
//!
//! struct A;
//! impl WithConst for A {
//! const TOTO: u8 = 1;
//! }
//!
//! struct B;
//! impl WithConst for B {
//! const TOTO: u8 = 2;
//! }
//! struct C;
//! impl WithConst for C {
//! const TOTO: u8 = 2;
//! }
//!
//! enum Enum {
//! A(A),
//! B(B),
//! C(C),
//! }
//!
//! impl Enum {
//! delegate! {
//! to match self {
//! Self::A(a) => a,
//! Self::B(b) => b,
//! Self::C(c) => { println!("hello from c"); c },
//! } {
//! #[const(WithConst::TOTO)]
//! fn get_toto(&self) -> u8;
//! }
//! }
//! }
//!
//! assert_eq!(Enum::A(A).get_toto(), <A as WithConst>::TOTO);
//! ```
//!
//! - Delegate to fields
//! ```rust
//! use delegate::delegate;
//!
//! struct Datum {
//! value: u32,
//! error: u32,
//! }
//!
//! struct DatumWrapper(Datum);
//!
//! impl DatumWrapper {
//! delegate! {
//! to self.0 {
//! /// Get the value of a nested field with the same name
//! #[field]
//! fn value(&self) -> u32;
//!
//! /// Get the value of a nested field with a different name
//! #[field(value)]
//! fn renamed_value(&self) -> u32;
//!
//! /// Get shared reference to a nested field
//! #[field(&value)]
//! fn value_ref(&self) -> &u32;
//!
//! /// Get mutable reference to a nested field
//! #[field(&mut value)]
//! fn value_ref_mut(&mut self) -> &mut u32;
//!
//! /// Get mutable reference to a nested field with the same name
//! #[field(&)]
//! fn error(&self) -> &u32;
//! }
//! }
//! }
//! ```
extern crate proc_macro;
use std::mem;
use attributes::AssociatedConstant;
use proc_macro::TokenStream;
use proc_macro2::Ident;
use quote::{quote, ToTokens};
use syn::parse::{Parse, ParseStream};
use syn::spanned::Spanned;
use syn::visit_mut::VisitMut;
use syn::{parse_quote, Error, Expr, ExprField, ExprMethodCall, FnArg, GenericParam, Meta};
use crate::attributes::{
combine_attributes, parse_method_attributes, parse_segment_attributes, ReturnExpression,
SegmentAttributes, TargetSpecifier,
};
mod attributes;
mod kw {
syn::custom_keyword!(to);
syn::custom_keyword!(target);
}
#[derive(Clone)]
enum ArgumentModifier {
Into,
AsRef,
Newtype,
}
#[derive(Clone)]
enum DelegatedInput {
Input {
parameter: syn::FnArg,
modifier: Option<ArgumentModifier>,
},
Argument(syn::Expr),
}
fn get_argument_modifier(attribute: syn::Attribute) -> Result<ArgumentModifier, Error> {
if let Meta::Path(mut path) = attribute.meta {
if path.segments.len() == 1 {
let segment = path.segments.pop().unwrap();
if segment.value().arguments.is_empty() {
let ident = segment.value().ident.to_string();
let ident = ident.as_str();
match ident {
"into" => return Ok(ArgumentModifier::Into),
"as_ref" => return Ok(ArgumentModifier::AsRef),
"newtype" => return Ok(ArgumentModifier::Newtype),
_ => (),
}
}
}
};
panic!("The attribute argument has to be `into` or `as_ref`, like this: `#[into] a: u32`.")
}
impl syn::parse::Parse for DelegatedInput {
fn parse(input: ParseStream) -> Result<Self, Error> {
let lookahead = input.lookahead1();
if lookahead.peek(syn::token::Bracket) {
let content;
let _bracket_token = syn::bracketed!(content in input);
let expression: syn::Expr = content.parse()?;
Ok(Self::Argument(expression))
} else {
let (input, modifier) = if lookahead.peek(syn::token::Pound) {
let mut attributes = input.call(tolerant_outer_attributes)?;
if attributes.len() > 1 {
panic!("You can specify at most a single attribute for each parameter in a delegated method");
}
let modifier = get_argument_modifier(attributes.pop().unwrap())
.expect("Could not parse argument modifier attribute");
let input: syn::FnArg = input.parse()?;
(input, Some(modifier))
} else {
(input.parse()?, None)
};
Ok(Self::Input {
parameter: input,
modifier,
})
}
}
}
struct DelegatedMethod {
method: syn::TraitItemFn,
attributes: Vec<syn::Attribute>,
visibility: syn::Visibility,
arguments: syn::punctuated::Punctuated<syn::Expr, syn::Token![,]>,
}
// Given an input parameter from a function signature, create a function
// argument used to call the delegate function: omit receiver, extract an
// identifier from a typed input parameter (and wrap it in an `Expr`).
fn parse_input_into_argument_expression(
function_name: &Ident,
input: &syn::FnArg,
) -> Option<syn::Expr> {
match input {
// Parse inputs of the form `x: T` to retrieve their identifiers.
syn::FnArg::Typed(typed) => {
match &*typed.pat {
// This should not happen, I think. If it does,
// it will be ignored as if it were the
// receiver.
syn::Pat::Ident(ident) if ident.ident == "self" => None,
// Expression in the form `x: T`. Extract the
// identifier, wrap it in Expr for type compatibility with bracketed expressions,
// and append it
// to the argument list.
syn::Pat::Ident(ident) => {
let path_segment = syn::PathSegment {
ident: ident.ident.clone(),
arguments: syn::PathArguments::None,
};
let mut segments = syn::punctuated::Punctuated::new();
segments.push(path_segment);
let path = syn::Path {
leading_colon: None,
segments,
};
let ident_as_expr = syn::Expr::from(syn::ExprPath {
attrs: Vec::new(),
qself: None,
path,
});
Some(ident_as_expr)
}
// Other more complex argument expressions are not covered.
_ => panic!(
"You have to use simple identifiers for delegated method parameters ({})",
function_name // The signature is not constructed yet. We make due.
),
}
}
// Skip any `self`/`&self`/`&mut self` argument, since
// it does not appear in the argument list and it's
// already added to the parameter list.
syn::FnArg::Receiver(_receiver) => None,
}
}
impl syn::parse::Parse for DelegatedMethod {
fn parse(input: ParseStream) -> Result<Self, Error> {
let attributes = input.call(tolerant_outer_attributes)?;
let visibility = input.call(syn::Visibility::parse)?;
// Unchanged from Parse from TraitItemMethod
let constness: Option<syn::Token![const]> = input.parse()?;
let asyncness: Option<syn::Token![async]> = input.parse()?;
let unsafety: Option<syn::Token![unsafe]> = input.parse()?;
let abi: Option<syn::Abi> = input.parse()?;
let fn_token: syn::Token![fn] = input.parse()?;
let ident: Ident = input.parse()?;
let generics: syn::Generics = input.parse()?;
let content;
let paren_token = syn::parenthesized!(content in input);
// Parse inputs (method parameters) and arguments. The parameters
// constitute the parameter list of the signature of the delegating
// method so it must include all inputs, except bracketed expressions.
// The argument list constitutes the list of arguments used to call the
// delegated function. It must include all inputs, excluding the
// receiver (self-type) input. The arguments must all be parsed to
// retrieve the expressions inside of the brackets as well as variable
// identifiers of ordinary inputs. The arguments must preserve the order
// of the inputs.
let delegated_inputs = content.parse_terminated(DelegatedInput::parse, syn::Token![,])?;
let mut inputs: syn::punctuated::Punctuated<syn::FnArg, syn::Token![,]> =
syn::punctuated::Punctuated::new();
let mut arguments: syn::punctuated::Punctuated<syn::Expr, syn::Token![,]> =
syn::punctuated::Punctuated::new();
// First, combine the cases for pairs with cases for end, to remove
// redundancy below.
delegated_inputs
.into_pairs()
.map(|punctuated_pair| match punctuated_pair {
syn::punctuated::Pair::Punctuated(item, comma) => (item, Some(comma)),
syn::punctuated::Pair::End(item) => (item, None),
})
.for_each(|pair| match pair {
// This input is a bracketed argument (eg. `[ self.x ]`). It
// is omitted in the signature of the delegator, but the
// expression inside the brackets is used in the body of the
// delegator, as an arugnment to the delegated function (eg.
// `self.x`). The argument needs to be generated in the
// appropriate position with respect other arguments and non-
// argument inputs. As long as inputs are added to the
// `arguments` vector in order of occurance, this is trivial.
(DelegatedInput::Argument(argument), maybe_comma) => {
arguments.push_value(argument);
if let Some(comma) = maybe_comma {
arguments.push_punct(comma)
}
}
// The input is a standard function parameter with a name and
// a type (eg. `x: T`). This input needs to be reflected in
// the delegator signature as is (eg. `x: T`). The identifier
// also needs to be included in the argument list in part
// (eg. `x`). The argument list needs to preserve the order of
// the inputs with relation to arguments (see above), so the
// parsing is best done here (previously it was done at
// generation).
(
DelegatedInput::Input {
parameter,
modifier,
},
maybe_comma,
) => {
inputs.push_value(parameter.clone());
if let Some(comma) = maybe_comma {
inputs.push_punct(comma);
}
let maybe_argument = parse_input_into_argument_expression(&ident, ¶meter);
if let Some(mut argument) = maybe_argument {
let span = argument.span();
if let Some(modifier) = modifier {
let method_call = |name: &str| {
syn::Expr::from(ExprMethodCall {
attrs: vec![],
receiver: Box::new(argument.clone()),
dot_token: Default::default(),
method: Ident::new(name, span),
turbofish: None,
paren_token,
args: Default::default(),
})
};
let field_call = || {
syn::Expr::from(ExprField {
attrs: vec![],
base: Box::new(argument.clone()),
dot_token: Default::default(),
member: syn::Member::Unnamed(0.into()),
})
};
match modifier {
ArgumentModifier::Into => {
argument = method_call("into");
}
ArgumentModifier::AsRef => {
argument = method_call("as_ref");
}
ArgumentModifier::Newtype => argument = field_call(),
}
}
arguments.push(argument);
if let Some(comma) = maybe_comma {
arguments.push_punct(comma);
}
}
}
});
// Unchanged from Parse from TraitItemMethod
let output: syn::ReturnType = input.parse()?;
let where_clause: Option<syn::WhereClause> = input.parse()?;
// This needs to be generated manually, because inputs need to be
// separated into actual inputs that go in the signature (the
// parameters) and the additional expressions in square brackets which
// go into the arguments vector (artguments of the call on the method
// on the inner object).
let signature = syn::Signature {
constness,
asyncness,
unsafety,
abi,
fn_token,
ident,
paren_token,
inputs,
output,
variadic: None,
generics: syn::Generics {
where_clause,
..generics
},
};
// Check if the input contains a semicolon or a brace. If it contains
// a semicolon, we parse it (to retain token location information) and
// continue. However, if it contains a brace, this indicates that
// there is a default definition of the method. This is not supported,
// so in that case we error out.
let lookahead = input.lookahead1();
let semi_token: Option<syn::Token![;]> = if lookahead.peek(syn::Token![;]) {
Some(input.parse()?)
} else {
panic!(
"Do not include implementation of delegated functions ({})",
signature.ident
);
};
// This needs to be populated from scratch because of the signature above.
let method = syn::TraitItemFn {
// All attributes are attached to `DelegatedMethod`, since they
// presumably pertain to the process of delegation, not the
// signature of the delegator.
attrs: Vec::new(),
sig: signature,
default: None,
semi_token,
};
Ok(DelegatedMethod {
method,
attributes,
visibility,
arguments,
})
}
}
struct DelegatedSegment {
delegator: syn::Expr,
methods: Vec<DelegatedMethod>,
segment_attrs: SegmentAttributes,
}
impl syn::parse::Parse for DelegatedSegment {
fn parse(input: ParseStream) -> Result<Self, Error> {
let attributes = input.call(tolerant_outer_attributes)?;
let segment_attrs = parse_segment_attributes(&attributes);
if let Ok(keyword) = input.parse::<kw::target>() {
return Err(Error::new(keyword.span(), "You are using the old `target` expression, which is deprecated. Please replace `target` with `to`."));
} else {
input.parse::<kw::to>()?;
}
syn::Expr::parse_without_eager_brace(input).and_then(|delegator| {
let content;
syn::braced!(content in input);
let mut methods = vec![];
while !content.is_empty() {
methods.push(
content
.parse::<DelegatedMethod>()
.expect("Cannot parse delegated method"),
);
}
Ok(DelegatedSegment {
delegator,
methods,
segment_attrs,
})
})
}
}
struct DelegationBlock {
segments: Vec<DelegatedSegment>,
}
impl syn::parse::Parse for DelegationBlock {
fn parse(input: ParseStream) -> Result<Self, Error> {
let mut segments = vec![];
while !input.is_empty() {
segments.push(input.parse()?);
}
Ok(DelegationBlock { segments })
}
}
/// Returns true if there are any `inline` attributes in the input.
fn has_inline_attribute(attrs: &[&syn::Attribute]) -> bool {
attrs.iter().any(|attr| {
if let syn::AttrStyle::Outer = attr.style {
attr.path().is_ident("inline")
} else {
false
}
})
}
struct MatchVisitor<F>(F);
impl<F: Fn(&Expr) -> proc_macro2::TokenStream> VisitMut for MatchVisitor<F> {
fn visit_arm_mut(&mut self, arm: &mut syn::Arm) {
let transformed = self.0(&arm.body);
arm.body = parse_quote!(#transformed);
}
}
#[proc_macro]
pub fn delegate(tokens: TokenStream) -> TokenStream {
let block: DelegationBlock = syn::parse_macro_input!(tokens);
let sections = block.segments.iter().map(|delegator| {
let delegated_expr = &delegator.delegator;
let functions = delegator.methods.iter().map(|method| {
let input = &method.method;
let mut signature = input.sig.clone();
if let Expr::Closure(closure) = delegated_expr {
let additional_inputs: Vec<FnArg> = closure
.inputs
.iter()
.map(|input| {
if let syn::Pat::Type(pat_type) = input {
syn::parse_quote!(#pat_type)
} else {
panic!(
"Use a type pattern (`a: u32`) for delegation closure arguments"
);
}
})
.collect();
let mut origin_inputs = mem::take(&mut signature.inputs).into_iter();
// When delegating methods, `first_input` should be self or similar receivers
// Then we need to move it to first
// When delegating associated methods, it may be a trivial argument or does not even exist
// We just keep the origin order.
let first_input = origin_inputs.next();
match first_input {
Some(FnArg::Receiver(receiver)) => {
signature.inputs.push(FnArg::Receiver(receiver));
signature.inputs.extend(additional_inputs);
}
Some(first_input) => {
signature.inputs.extend(additional_inputs);
signature.inputs.push(first_input);
}
_ => {
signature.inputs.extend(additional_inputs);
}
}
signature.inputs.extend(origin_inputs);
}
let attributes = parse_method_attributes(&method.attributes, input);
let attributes = combine_attributes(attributes, &delegator.segment_attrs);
if input.default.is_some() {
panic!(
"Do not include implementation of delegated functions ({})",
signature.ident
);
}
// Generate an argument vector from Punctuated list.
let args: Vec<Expr> = method.arguments.clone().into_iter().collect();
// Get name (or index) of the target method or field
let name = match &attributes.target_specifier {
Some(target) => target.get_member(&input.sig.ident),
None => input.sig.ident.clone().into(),
};
let inline = if has_inline_attribute(&attributes.attributes) {
quote!()
} else {
quote! { #[inline] }
};
let visibility = &method.visibility;
let is_method = method.method.sig.receiver().is_some();
let associated_const = &attributes.associated_constant;
let expr_attr = &attributes.expr_attr;
// Use the body of a closure (like `|k: u32| <body>`) as the delegation expression
let delegated_body = if let Expr::Closure(closure) = delegated_expr {
&closure.body
} else {
delegated_expr
};
let span = input.span();
let generate_await = attributes
.generate_await
.unwrap_or_else(|| method.method.sig.asyncness.is_some());
// fn method<'a, A, B> -> method::<A, B>
let generic_params = &method.method.sig.generics.params;
let generics = if generic_params.is_empty() {
quote::quote! {}
} else {
let span = generic_params.span();
let mut params: syn::punctuated::Punctuated<
proc_macro2::TokenStream,
syn::Token![,],
> = syn::punctuated::Punctuated::new();
for param in generic_params.iter() {
let token = match param {
GenericParam::Lifetime(_) => {
// Do not pass lifetimes to generic arguments explicitly to avoid
// things like https://doc.rust-lang.org/error_codes/E0794.html
// See https://github.com/Kobzol/rust-delegate/issues/85.
continue;
}
GenericParam::Type(t) => {
let token = &t.ident;
let span = t.span();
quote::quote_spanned! {span=> #token }
}
GenericParam::Const(c) => {
let token = &c.ident;
let span = c.span();
quote::quote_spanned! {span=> #token }
}
};
params.push(token);
}
quote::quote_spanned! {span=> ::<#params> }
};
let modify_expr = |expr: &Expr| {
let body = if let Some(target_trait) = &attributes.target_trait {
quote::quote! { #target_trait::#name#generics(#expr, #(#args),*) }
} else if let Some(AssociatedConstant {
const_name,
trait_path,
}) = associated_const
{
let return_type = &signature.output;
quote::quote! {{
const fn get_const<T: #trait_path>(t: &T) #return_type {
<T as #trait_path>::#const_name
}
get_const(#expr)
}}
} else if is_method {
match &attributes.target_specifier {
None | Some(TargetSpecifier::Method(_)) => {
quote::quote! { #expr.#name#generics(#(#args),*) }
}
Some(TargetSpecifier::Field(target)) => {
let reference = target.reference_tokens();
quote::quote! { #reference#expr.#name }
}
}
} else {
quote::quote! { #expr::#name#generics(#(#args),*) }
};
let mut body = if generate_await {
quote::quote! { #body.await }
} else {
body
};
for expression in &attributes.expressions {
match expression {
ReturnExpression::Into(type_name) => {
body = match type_name {
Some(name) => {
quote::quote! { ::core::convert::Into::<#name>::into(#body) }
}
None => quote::quote! { ::core::convert::Into::into(#body) },
};
}
ReturnExpression::TryInto => {
body = quote::quote! { ::core::convert::TryInto::try_into(#body) };
}
ReturnExpression::Unwrap => {
body = quote::quote! { #body.unwrap() };
}
}
}
body
};
let mut body = if let Expr::Match(expr_match) = delegated_body {
let mut expr_match = expr_match.clone();
MatchVisitor(modify_expr).visit_expr_match_mut(&mut expr_match);
expr_match.into_token_stream()
} else {
modify_expr(delegated_body)
};
if let syn::ReturnType::Default = &signature.output {
body = quote::quote! { #body; };
};
if let Some(expr_template) = expr_attr {
body = expr_template.expand_template(&body);
}
let attrs = &attributes.attributes;
quote::quote_spanned! {span=>
#(#attrs)*
#inline
#visibility #signature {
#body
}
}
});
quote! { #(#functions)* }
});
let result = quote! {
#(#sections)*
};
result.into()
}
// we cannot use `Attributes::parse_outer` directly, because it does not allow keywords to appear
// in meta path positions, i.e., it does not accept `#[await(true)]`.
// related issue: https://github.com/dtolnay/syn/issues/1458
fn tolerant_outer_attributes(input: ParseStream) -> syn::Result<Vec<syn::Attribute>> {
use proc_macro2::{Delimiter, TokenTree};
use syn::{
bracketed,
ext::IdentExt,
parse::discouraged::Speculative,
token::{Brace, Bracket, Paren},
AttrStyle, Attribute, ExprLit, Lit, MacroDelimiter, MetaList, MetaNameValue, Path, Result,
Token,
};
fn tolerant_attr(input: ParseStream) -> Result<Attribute> {
let content;
Ok(Attribute {
pound_token: input.parse()?,
style: AttrStyle::Outer,
bracket_token: bracketed!(content in input),
meta: content.call(tolerant_meta)?,
})
}
// adapted from `impl Parse for Meta`
fn tolerant_meta(input: ParseStream) -> Result<Meta> {
// Try to parse as Meta
if let Ok(meta) = input.call(Meta::parse) {
Ok(meta)
} else {
// If it's not possible, try to parse it as any identifier, to support #[await]
let path = Path::from(input.call(Ident::parse_any)?);
if input.peek(Paren) || input.peek(Bracket) || input.peek(Brace) {
// adapted from the private `syn::attr::parse_meta_after_path`
input.step(|cursor| {
if let Some((TokenTree::Group(g), rest)) = cursor.token_tree() {
let span = g.delim_span();
let delimiter = match g.delimiter() {
Delimiter::Parenthesis => MacroDelimiter::Paren(Paren(span)),
Delimiter::Brace => MacroDelimiter::Brace(Brace(span)),
Delimiter::Bracket => MacroDelimiter::Bracket(Bracket(span)),
Delimiter::None => {
return Err(cursor.error("expected delimiter"));
}
};
Ok((
Meta::List(MetaList {
path,
delimiter,
tokens: g.stream(),
}),
rest,
))
} else {
Err(cursor.error("expected delimiter"))
}
})
} else if input.peek(Token![=]) {
// adapted from the private `syn::attr::parse_meta_name_value_after_path`
let eq_token = input.parse()?;
let ahead = input.fork();
let value = match ahead.parse::<Option<Lit>>()? {
// this branch is probably for speeding up the parsing for doc comments etc.
Some(lit) if ahead.is_empty() => {
input.advance_to(&ahead);
Expr::Lit(ExprLit {
attrs: Vec::new(),
lit,
})
}
_ => input.parse()?,
};
Ok(Meta::NameValue(MetaNameValue {
path,
eq_token,
value,
}))
} else {
Ok(Meta::Path(path))
}
}
}
let mut attrs = Vec::new();
while input.peek(Token![#]) {
attrs.push(input.call(tolerant_attr)?);
}
Ok(attrs)
}
================================================
FILE: tests/argument_modifier.rs
================================================
use delegate::delegate;
struct MyNewU32(u32);
trait Foo {
fn bar(&self, x: Self);
}
impl Foo for u32 {
fn bar(&self, x: Self) {}
}
impl From<MyNewU32> for u32 {
fn from(value: MyNewU32) -> Self {
value.0
}
}
impl Foo for MyNewU32 {
delegate! {
to self.0 {
fn bar(&self, #[into] x: Self);
}
}
}
struct Bar {
foo: String,
}
impl<T> PartialEq<T> for Bar
where
T: AsRef<str> + ?Sized,
{
delegate! {
to self.foo {
fn eq(&self, #[as_ref] other: &T) -> bool;
}
}
}
struct Baz(Vec<u32>);
impl Baz {
delegate! {
to self.0 {
fn extend(&mut self, #[newtype] other: Baz);
}
}
}
================================================
FILE: tests/associated_const_delegation.rs
================================================
extern crate delegate;
use delegate::delegate;
#[test]
fn test_delegate_constant() {
trait WithConst {
const TOTO: u8;
}
struct A;
impl WithConst for A {
const TOTO: u8 = 1;
}
struct B;
impl WithConst for B {
const TOTO: u8 = 2;
}
struct C;
impl WithConst for C {
const TOTO: u8 = 2;
}
enum Enum {
A(A),
B(B),
C(C),
}
impl Enum {
delegate! {
to match self {
Self::A(a) => a,
Self::B(b) => b,
Self::C(c) => { println!("hello from c"); c },
} {
#[const(WithConst::TOTO)]
fn get_toto(&self) -> u8;
}
}
}
let a = Enum::A(A);
assert_eq!(a.get_toto(), <A as WithConst>::TOTO);
let b = Enum::B(B);
assert_eq!(b.get_toto(), <B as WithConst>::TOTO);
let c = Enum::C(C);
assert_eq!(c.get_toto(), <C as WithConst>::TOTO);
}
#[test]
fn multiple_consts() {
trait Foo {
const A: u32;
const B: u32;
}
struct A;
impl Foo for A {
const A: u32 = 1;
const B: u32 = 2;
}
struct Wrapper(A);
impl Wrapper {
delegate! {
to &self.0 {
#[const(Foo::A)]
fn a(&self) -> u32;
#[const(Foo::B)]
fn b(&self) -> u32;
}
}
}
let wrapper = Wrapper(A);
assert_eq!(wrapper.a(), <A as Foo>::A);
assert_eq!(wrapper.b(), <A as Foo>::B);
}
================================================
FILE: tests/async_await.rs
================================================
extern crate delegate;
use delegate::delegate;
use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};
#[test]
fn test_async_await() {
struct Inner;
impl Inner {
pub async fn method(&self, num: u32) -> u32 {
num
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
to self.inner {
pub(crate) async fn method(&self, num: u32) -> u32;
#[call(method)]
pub(crate) async fn unit(&self, num: u32);
#[into]
#[call(method)]
pub(crate) async fn with_into(&self, num: u32) -> u64;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert_eq!(::futures::executor::block_on(wrapper.method(3)), 3);
assert_eq!(::futures::executor::block_on(wrapper.unit(3)), ());
assert_eq!(::futures::executor::block_on(wrapper.with_into(3)), 3_u64);
}
#[test]
fn test_async_trait() {
use async_trait::async_trait;
#[async_trait]
trait Inner {
async fn method(&self, num: u32) -> u32;
}
struct InnerImpl;
#[async_trait]
impl Inner for InnerImpl {
async fn method(&self, num: u32) -> u32 {
num
}
}
struct Wrapper<T> {
inner: T,
}
impl<T: Inner> Wrapper<T> {
delegate! {
to self.inner {
pub(crate) async fn method(&self, num: u32) -> u32;
#[call(method)]
pub(crate) async fn unit(&self, num: u32);
#[into]
#[call(method)]
pub(crate) async fn with_into(&self, num: u32) -> u64;
}
}
}
let wrapper = Wrapper { inner: InnerImpl };
assert_eq!(::futures::executor::block_on(wrapper.method(3)), 3);
assert_eq!(::futures::executor::block_on(wrapper.unit(3)), ());
assert_eq!(::futures::executor::block_on(wrapper.with_into(3)), 3_u64);
}
#[test]
fn test_bridge_async_to_sync() {
struct UserRepo;
impl UserRepo {
fn foo(&self) {}
}
struct SharedRepo(tokio::sync::Mutex<UserRepo>);
impl SharedRepo {
delegate! {
to self.0.lock().await {
#[await(false)]
async fn foo(&self);
}
}
}
}
#[test]
fn test_bridge_sync_to_async() {
struct Fut;
impl Future for Fut {
type Output = u32;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
todo!()
}
}
struct UserRepo;
impl UserRepo {
fn foo(&self) -> Fut {
Fut
}
}
struct SharedRepo(UserRepo);
impl SharedRepo {
delegate! {
to self.0 {
#[await(true)]
async fn foo(&self) -> u32;
}
}
}
}
================================================
FILE: tests/closure.rs
================================================
use delegate::delegate;
use std::cell::OnceCell;
#[test]
fn test_delegate_closure() {
struct Inner(u32);
impl Inner {
fn method(&self, n: u32) -> u32 {
self.0 + n
}
fn method2(&self, n: u32) -> u32 {
self.0 - n
}
}
struct Wrapper {
inner: OnceCell<Inner>,
}
impl Wrapper {
pub fn new() -> Self {
Self {
inner: OnceCell::new(),
}
}
fn content(&self, val: u32) -> &Inner {
self.inner.get_or_init(|| Inner(val))
}
delegate! {
to |k: u32| self.content(k) {
pub fn method(&self, num: u32) -> u32;
pub fn method2(&self, num: u32) -> u32;
}
}
}
let wrapper = Wrapper::new();
assert_eq!(wrapper.method(1, 2), 3);
assert_eq!(wrapper.method2(1, 1), 0);
assert_eq!(wrapper.method(1, 3), 4);
assert_eq!(wrapper.method2(1, 0), 1);
}
#[test]
fn test_delegate_closure_associated_function() {
struct Inner;
impl Inner {
fn method(n: u32) -> u32 {
n + 1
}
fn method2(n: u32) -> u32 {
n - 1
}
}
struct Wrapper;
impl Wrapper {
// Doesn't really make sense, but should compile
delegate! {
to |k: u32| Inner {
pub fn method(num: u32) -> u32;
pub fn method2(num: u32) -> u32;
}
}
}
assert_eq!(Wrapper::method(1, 2), 3);
assert_eq!(Wrapper::method2(1, 1), 0);
assert_eq!(Wrapper::method(1, 3), 4);
assert_eq!(Wrapper::method(1, 0), 1);
}
================================================
FILE: tests/delegate_to_enum.rs
================================================
use delegate::delegate;
enum Enum {
A(A),
B(B),
C { v: C },
}
struct A {
val: usize,
}
impl A {
fn dbg_inner(&self) -> usize {
dbg!(self.val);
1
}
fn into_num(&self) -> u8 {
1
}
}
struct B {
val_a: String,
}
impl B {
fn dbg_inner(&self) -> usize {
dbg!(self.val_a.clone());
2
}
fn into_num(&self) -> u64 {
2
}
}
struct C {
val_c: f64,
}
impl C {
fn dbg_inner(&self) -> usize {
dbg!(self.val_c);
3
}
fn into_num(&self) -> usize {
3
}
}
impl Enum {
delegate! {
to match self {
Enum::A(a) => a,
Enum::B(b) => { println!("i am b"); b },
Enum::C { v: c } => { c },
} {
fn dbg_inner(&self) -> usize;
#[into]
fn into_num(&self) -> IntoUsize;
}
}
}
#[derive(Eq, PartialEq, Debug)]
struct IntoUsize(usize);
impl From<usize> for IntoUsize {
fn from(value: usize) -> Self {
Self(value)
}
}
impl From<u64> for IntoUsize {
fn from(value: u64) -> Self {
Self(value as usize)
}
}
impl From<u8> for IntoUsize {
fn from(value: u8) -> Self {
Self(value as usize)
}
}
#[test]
fn test_delegate_enum_method() {
let a = Enum::A(A { val: 1 });
assert_eq!(a.dbg_inner(), 1);
let b = Enum::B(B {
val_a: "a".to_string(),
});
assert_eq!(b.dbg_inner(), 2);
let c = Enum::C {
v: C { val_c: 1.0 },
};
assert_eq!(c.dbg_inner(), 3);
}
#[test]
fn test_delegate_enum_into() {
let a = Enum::A(A { val: 1 });
assert_eq!(a.into_num(), IntoUsize(1));
let b = Enum::B(B {
val_a: "".to_string(),
});
assert_eq!(b.into_num(), IntoUsize(2));
let c = Enum::C {
v: C { val_c: 0.0 },
};
assert_eq!(c.into_num(), IntoUsize(3));
}
================================================
FILE: tests/delegation.rs
================================================
use delegate::delegate;
#[test]
fn test_expansions() {
macrotest::expand("tests/expand/*.rs");
}
#[test]
fn test_delegation() {
struct Inner;
impl Inner {
fn fun_generic<S: Copy>(self, s: S) -> S {
s
}
fn fun1(self, a: u32, b: u32) -> u32 {
a + b
}
fn fun2(mut self, a: u32, b: u32) -> u32 {
a + b
}
fn fun3(&self, a: u32, b: u32) -> u32 {
a + b
}
fn fun4(&mut self, a: u32, b: u32) -> u32 {
a + b
}
fn fun5(self: Self, a: u32, b: u32) -> u32 {
a + b
}
fn fun6(mut self: Self, a: u32, b: u32) -> u32 {
a + b
}
}
struct Outer {
inner: Inner,
inner2: Inner,
}
impl Outer {
pub fn new() -> Outer {
Outer {
inner: Inner,
inner2: Inner,
}
}
delegate! {
to self.inner {
fn fun_generic<S: Copy>(self, s: S) -> S;
fn fun1(self, a: u32, b: u32) -> u32;
fn fun2(mut self, a: u32, b: u32) -> u32;
fn fun3(&self, a: u32, b: u32) -> u32;
}
to self.inner2 {
fn fun4(&mut self, a: u32, b: u32) -> u32;
fn fun5(self: Self, a: u32, b: u32) -> u32;
fn fun6(mut self: Self, a: u32, b: u32) -> u32;
}
}
}
assert_eq!(Outer::new().fun_generic(5), 5);
assert_eq!(Outer::new().fun1(1, 2), 3);
assert_eq!(Outer::new().fun2(1, 2), 3);
assert_eq!(Outer::new().fun3(1, 2), 3);
assert_eq!(Outer::new().fun4(1, 2), 3);
assert_eq!(Outer::new().fun5(1, 2), 3);
assert_eq!(Outer::new().fun6(1, 2), 3);
}
#[test]
fn test_delegate_self() {
trait Foo {
fn foo(&self) -> u32;
}
struct S;
impl S {
fn foo(&self) -> u32 {
1
}
}
impl Foo for S {
delegate! {
to self {
fn foo(&self) -> u32;
}
}
}
let s = S;
assert_eq!(Foo::foo(&s), 1);
}
#[test]
fn test_delegate_tuple() {
trait Foo {
fn foo(&self) -> u32;
}
struct S;
impl S {
fn foo(&self) -> u32 {
1
}
}
struct T(S);
impl Foo for T {
delegate! {
to self.0 {
fn foo(&self) -> u32;
}
}
}
let s = S;
let t = T(s);
assert_eq!(Foo::foo(&t), 1);
}
================================================
FILE: tests/expand/fields.expanded.rs
================================================
use delegate::delegate;
struct Datum {
value: u32,
error: u32,
xy: (f32, f32),
}
struct DatumWrapper(Datum);
impl DatumWrapper {
fn get_inner(&self) -> &Datum {
&self.0
}
/// Expands to `self.0.value`
#[inline]
fn value(&self) -> u32 {
self.0.value
}
/// Expands to `self.0.value`
#[inline]
fn renamed_value(&self) -> u32 {
self.0.value
}
/// Expands to `&self.0.value`
#[inline]
fn renamed_value_ref(&self) -> &u32 {
&self.0.value
}
/// Expands to `&mut self.0.value`
#[inline]
fn renamed_value_ref_mut(&mut self) -> &mut u32 {
&mut self.0.value
}
/// Expands to `&self.0.error` (demonstrates `&` without a field name)
#[inline]
fn error(&self) -> &u32 {
&self.0.error
}
/// Expands to `self.0.xy.0` (demonstrates unnamed field access by value)
#[inline]
fn x(&self) -> f32 {
self.0.xy.0
}
/// Expands to `&self.0.xy.1` (demonstrates unnamed field access by reference)
#[inline]
fn y(&self) -> &f32 {
&self.0.xy.1
}
/// Expands to `&self.get_inner().value`
#[inline]
fn value_ref_via_get_inner(&self) -> &u32 {
&self.get_inner().value
}
}
================================================
FILE: tests/expand/fields.rs
================================================
use delegate::delegate;
struct Datum {
value: u32,
error: u32,
xy: (f32, f32)
}
struct DatumWrapper(Datum);
impl DatumWrapper {
fn get_inner(&self) -> &Datum {
&self.0
}
delegate! {
to self.0 {
/// Expands to `self.0.value`
#[field]
fn value(&self) -> u32;
/// Expands to `self.0.value`
#[field(value)]
fn renamed_value(&self) -> u32;
/// Expands to `&self.0.value`
#[field(&value)]
fn renamed_value_ref(&self) -> &u32;
/// Expands to `&mut self.0.value`
#[field(&mut value)]
fn renamed_value_ref_mut(&mut self) -> &mut u32;
/// Expands to `&self.0.error` (demonstrates `&` without a field name)
#[field(&)]
fn error(&self) -> &u32;
}
to self.0.xy {
/// Expands to `self.0.xy.0` (demonstrates unnamed field access by value)
#[field(0)]
fn x(&self) -> f32;
/// Expands to `&self.0.xy.1` (demonstrates unnamed field access by reference)
#[field(&1)]
fn y(&self) -> &f32;
}
to self.get_inner() {
/// Expands to `&self.get_inner().value`
#[field(&value)]
fn value_ref_via_get_inner(&self) -> &u32;
}
}
}
================================================
FILE: tests/expr.rs
================================================
use delegate::delegate;
use std::sync::Mutex;
struct Inner;
impl Inner {
pub fn method(&self, num: u32) -> u32 {
num
}
pub fn method2(&self, num: u32) -> u32 {
num
}
}
struct Wrapper {
inner: Mutex<Inner>,
}
fn global_fn() -> Inner {
Inner
}
impl Wrapper {
delegate! {
to self.inner.lock().unwrap() {
pub(crate) fn method(&self, num: u32) -> u32;
}
to global_fn() {
pub(crate) fn method2(&self, num: u32) -> u32;
}
}
}
#[test]
fn test_mutex() {
let wrapper = Wrapper {
inner: Mutex::new(Inner),
};
assert_eq!(wrapper.method(3), 3);
assert_eq!(wrapper.method2(3), 3);
}
#[test]
fn test_index() {
struct Inner;
impl Inner {
pub fn method(&self, num: u32) -> u32 {
num
}
}
struct Wrapper {
index: usize,
items: Vec<Inner>,
}
impl Wrapper {
delegate! {
to self.items[self.index] {
fn method(&self, num: u32) -> u32;
}
}
}
let wrapper = Wrapper {
index: 0,
items: vec![Inner],
};
assert_eq!(wrapper.method(3), 3);
}
================================================
FILE: tests/expr_attribute.rs
================================================
extern crate delegate;
use delegate::delegate;
#[test]
fn delegate_with_custom_expr() {
struct A(Vec<u8>);
impl A {
delegate! {
to self.0 {
#[expr(*$.unwrap())]
fn get(&self, idx: usize) -> u8;
#[call(get)]
#[expr($?.checked_pow(2))]
fn get_checked_pow_2(&self, idx: usize) -> Option<u8>;
}
}
}
let a = A(vec![2, 3, 4, 5]);
assert_eq!(a.get(0), 2);
assert_eq!(a.get_checked_pow_2(0), Some(4));
// out-of-bounds behavior
assert!(std::panic::catch_unwind(|| a.get(4)).is_err());
assert_eq!(a.get_checked_pow_2(4), None);
}
#[test]
fn delegate_without_placeholder() {
struct A(Vec<u8>);
impl A {
delegate! {
to self.0 {
#[expr(Some("test"))]
fn get_name(&self) -> Option<&'static str>;
}
}
}
let a = A(vec![2, 3, 4, 5]);
assert_eq!(a.get_name(), Some("test"));
}
================================================
FILE: tests/fields.rs
================================================
use delegate::delegate;
struct Datum {
value: u32,
error: u32,
xy: (f32, f32),
}
struct DatumWrapper(Datum);
impl DatumWrapper {
fn get_inner(&self) -> &Datum {
&self.0
}
delegate! {
to self.0 {
/// Expands to `self.0.value`
#[field]
fn value(&self) -> u32;
/// Expands to `self.0.value`
#[field(value)]
fn renamed_value(&self) -> u32;
/// Expands to `&self.0.value`
#[field(&value)]
fn renamed_value_ref(&self) -> &u32;
/// Expands to `&mut self.0.value`
#[field(&mut value)]
fn renamed_value_ref_mut(&mut self) -> &mut u32;
/// Expands to `&self.0.error` (demonstrates `&` without a field name)
#[field(&)]
fn error(&self) -> &u32;
}
to self.0.xy {
/// Expands to `self.0.xy.0` (demonstrates unnamed field access by value)
#[field(0)]
fn x(&self) -> f32;
/// Expands to `&self.0.xy.1` (demonstrates unnamed field access by reference)
#[field(&1)]
fn y(&self) -> &f32;
}
to self.get_inner() {
/// Expands to `&self.get_inner().value`
#[field(&value)]
fn value_ref_via_get_inner(&self) -> &u32;
}
}
}
#[test]
fn test_fields() {
let mut wrapper = DatumWrapper(Datum {
value: 1,
error: 2,
xy: (3.0, 4.0),
});
assert_eq!(wrapper.value(), wrapper.0.value);
assert_eq!(wrapper.renamed_value(), wrapper.0.value);
assert_eq!(wrapper.renamed_value_ref(), &wrapper.0.value);
assert_eq!(wrapper.renamed_value_ref_mut(), &mut 1);
assert_eq!(wrapper.value_ref_via_get_inner(), &1);
assert_eq!(wrapper.error(), &wrapper.0.error);
assert_eq!(wrapper.x(), wrapper.0.xy.0);
assert_eq!(wrapper.y(), &wrapper.0.xy.1);
}
================================================
FILE: tests/function.rs
================================================
use delegate::delegate;
#[test]
fn test_delegate_function() {
struct A {}
impl A {
fn foo(a: u32) -> u32 {
a + 1
}
}
struct B;
impl B {
delegate! {
to A {
fn foo(a: u32) -> u32;
}
}
}
assert_eq!(B::foo(1), 2);
}
================================================
FILE: tests/generic.rs
================================================
use delegate::delegate;
use std::collections::HashSet;
use std::hash::Hash;
#[test]
fn test_generics_method() {
struct Foo;
impl Foo {
fn foo<'a, P, X>(&self) {}
}
struct Bar(Foo);
impl Bar {
delegate! {
to &self.0 {
fn foo<'a, P, X>(&self);
}
}
}
}
#[test]
fn test_generics_function() {
struct Foo;
impl Foo {
fn foo<P, X>() {}
}
struct Bar(Foo);
impl Bar {
delegate! {
to Foo {
fn foo<P, X>();
}
}
}
}
#[test]
fn test_generics_through_trait() {
trait A {
fn f<P>(&self) -> u32;
}
struct Foo;
impl A for Foo {
fn f<P>(&self) -> u32 {
0
}
}
struct Bar(Foo);
impl Bar {
delegate! {
to &self.0 {
#[through(A)]
fn f<P>(&self) -> u32;
}
}
}
let bar = Bar(Foo);
assert_eq!(bar.f::<u32>(), 0);
}
#[test]
fn test_generics_complex() {
struct Foo;
impl Foo {
fn foo<'a: 'static, X: Copy, #[allow(unused)] T>(&self) {}
}
struct Bar(Foo);
impl Bar {
delegate! {
to &self.0 {
fn foo<'a: 'static, X: Copy, #[allow(unused)] T>(&self);
}
}
}
}
#[test]
fn test_lifetime_late_bound() {
trait QSet<T>
where
T: PartialEq,
{
fn iter<'a>(&'a self) -> impl Iterator<Item = &'a T>
where
Self: Sized,
T: 'a;
}
impl<T: Eq + Hash> QSet<T> for HashSet<T> {
delegate! {
to self {
#[through(HashSet)]
fn iter<'a>(&'a self) -> impl Iterator<Item = &T>
where
Self: Sized, T: 'a;
}
}
}
}
================================================
FILE: tests/in_macro_expansion.rs
================================================
///
/// Tests that a macro can expand into a delegate block,
/// where the target comes from a macro variable.
///
use delegate::delegate;
trait Trait {
fn method_to_delegate(&self) -> bool;
}
struct Struct1();
impl Trait for Struct1 {
fn method_to_delegate(&self) -> bool {
true
}
}
struct Struct2(pub Struct1);
// We use a macro to impl 'Trait' for 'Struct2' such that
// the target is a variable in the macro.
macro_rules! some_macro {
(|$self:ident| $delegate_to:expr) => {
impl Trait for Struct2 {
delegate! {
// '$delegate_to' will expand to 'self.0' before ´delegate!' is expanded.
to $delegate_to {
fn method_to_delegate(&$self) -> bool;
}
}
}
};
}
some_macro! { |self | self.0 }
#[test]
fn test() {
assert!(Struct2(Struct1()).method_to_delegate());
}
================================================
FILE: tests/inline_args.rs
================================================
use delegate::delegate;
#[test]
fn test_inline_args() {
struct Inner;
impl Inner {
fn fun_generic<S: Copy>(self, s: S) -> S {
s
}
fn fun0(self) -> u32 {
42
}
fn fun1(self, a: u32) -> u32 {
a
}
fn fun2(self, a: u32, b: u32) -> u32 {
a + b
}
fn fun3(&self, a: u32, b: u32, c: u32) -> u32 {
a + b + c
}
}
struct Outer {
inner: Inner,
value: u32,
}
impl Outer {
pub fn new() -> Outer {
Outer {
inner: Inner,
value: 42,
}
}
delegate! {
to self.inner {
#[call(fun_generic)]
fn fun_generic(self, [ 42 ]) -> u32;
#[call(fun1)]
fn fun1_with_0(self, [ 0 ]) -> u32;
#[call(fun1)]
fn fun1_with_0_no_spaces(self, [0]) -> u32;
#[call(fun1)]
fn fun1_with_def(self, [ self.value ] ) -> u32;
fn fun2(self, [ 0 ], b: u32) -> u32;
}
}
}
assert_eq!(Outer::new().fun_generic(), 42);
assert_eq!(Outer::new().fun1_with_0(), 0);
assert_eq!(Outer::new().fun1_with_0_no_spaces(), 0);
assert_eq!(Outer::new().fun1_with_def(), 42);
assert_eq!(Outer::new().fun2(2), 2);
}
#[test]
fn test_mixed_args() {
use delegate::delegate;
struct Inner;
impl Inner {
pub fn polynomial(&self, a: i32, x: i32, b: i32, y: i32, c: i32) -> i32 {
a + x * x + b * y + c
}
}
struct Wrapper {
inner: Inner,
a: i32,
b: i32,
c: i32,
}
impl Wrapper {
delegate! {
to self.inner {
pub fn polynomial(&self, [ self.a ], x: i32, [ self.b ], y: i32, [ self.c ]) -> i32 ;
#[call(polynomial)]
pub fn linear(&self, [ 0 ], [ 0 ], [ self.b ], y: i32, [ self.c ]) -> i32 ;
}
}
pub fn new() -> Wrapper {
Wrapper {
inner: Inner,
a: 1,
b: 3,
c: 5,
}
}
}
assert_eq!(Wrapper::new().polynomial(2, 3), 19i32);
assert_eq!(Wrapper::new().linear(3), 14i32);
}
================================================
FILE: tests/nested.rs
================================================
use delegate::delegate;
struct Inner;
impl Inner {
pub fn method(&self, num: u32) -> u32 {
num
}
}
struct Inner2 {
inner: Inner,
}
struct Wrapper {
inner: Inner2,
}
impl Wrapper {
delegate! {
to self.inner.inner {
pub(crate) fn method(&self, num: u32) -> u32;
}
}
}
#[test]
fn test_nested() {
let wrapper = Wrapper {
inner: Inner2 { inner: Inner },
};
assert_eq!(wrapper.method(3), 3);
}
================================================
FILE: tests/returntype.rs
================================================
use delegate::delegate;
use std::convert::TryFrom;
#[test]
fn test_generic_returntype() {
trait TestTrait {
fn create(num: u32) -> Self;
}
impl TestTrait for u32 {
fn create(num: u32) -> Self {
num
}
}
struct Inner;
impl Inner {
pub fn method<T: TestTrait>(&self) -> T {
T::create(0)
}
}
struct Wrapper<T> {
inner: Inner,
s: T,
}
impl<T: TestTrait> Wrapper<T> {
delegate! {
to self.inner {
pub(crate) fn method(&self) -> T;
}
}
}
let wrapper = Wrapper { inner: Inner, s: 3 };
assert_eq!(wrapper.method(), 0);
}
#[test]
fn test_into() {
struct Inner;
impl Inner {
pub fn method(&self, num: u32) -> u32 {
num
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
to self.inner {
pub(crate) fn method(&self, num: u32);
#[into]
#[call(method)]
pub(crate) fn method_conv(&self, num: u32) -> u64;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert_eq!(wrapper.method(3), ());
assert_eq!(wrapper.method_conv(3), 3u64);
}
#[test]
fn test_try_into() {
struct A;
#[derive(Debug, PartialEq)]
struct B;
impl TryFrom<A> for B {
type Error = u32;
fn try_from(_value: A) -> Result<Self, Self::Error> {
Ok(B)
}
}
struct Inner;
impl Inner {
pub fn method(&self) -> A {
A
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
to self.inner {
#[try_into]
fn method(&self) -> Result<B, u32>;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert_eq!(wrapper.method(), Ok(B));
}
#[test]
fn test_try_into_unwrap() {
struct A;
#[derive(Debug, PartialEq)]
struct B;
impl TryFrom<A> for B {
type Error = u32;
fn try_from(_value: A) -> Result<Self, Self::Error> {
Ok(B)
}
}
struct Inner;
impl Inner {
pub fn method(&self) -> A {
A
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
to self.inner {
#[try_into]
#[unwrap]
fn method(&self) -> B;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert_eq!(wrapper.method(), B);
}
#[test]
fn test_unwrap_result() {
struct Inner;
impl Inner {
pub fn method(&self) -> Result<u32, ()> {
Ok(0)
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
to self.inner {
#[unwrap]
fn method(&self) -> u32;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert_eq!(wrapper.method(), 0);
}
#[test]
fn test_unwrap_option() {
struct Inner;
impl Inner {
pub fn method(&self) -> Option<u32> {
Some(0)
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
to self.inner {
#[unwrap]
fn method(&self) -> u32;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert_eq!(wrapper.method(), 0);
}
#[test]
#[should_panic]
fn test_unwrap_no_return() {
struct Inner;
impl Inner {
pub fn method(&self) -> Result<u32, ()> {
Err(())
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
to self.inner {
#[unwrap]
fn method(&self);
}
}
}
let wrapper = Wrapper { inner: Inner };
wrapper.method();
}
#[test]
fn test_unwrap_into() {
struct A(u32);
impl From<u32> for A {
fn from(value: u32) -> Self {
A(value)
}
}
struct Inner;
impl Inner {
pub fn method(&self) -> Result<u32, ()> {
Ok(0)
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
to self.inner {
#[unwrap]
#[into]
fn method(&self) -> A;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert!(matches!(wrapper.method(), A(0)));
}
#[test]
fn test_into_unwrap() {
struct A(u32);
impl From<A> for Result<u32, ()> {
fn from(value: A) -> Self {
Ok(value.0)
}
}
struct Inner;
impl Inner {
pub fn method(&self) -> A {
A(0)
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
to self.inner {
#[into(Result<u32, ()>)]
#[unwrap]
fn method(&self) -> u32;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert_eq!(wrapper.method(), 0);
}
================================================
FILE: tests/segment_attributes.rs
================================================
use delegate::delegate;
use std::convert::TryFrom;
#[test]
fn test_segment_unwrap() {
struct Inner;
impl Inner {
fn foo(&self, a: u32) -> Result<u32, ()> {
Ok(a)
}
fn bar(&self, a: u32) -> Result<u32, ()> {
Ok(a)
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
#[unwrap]
to self.inner {
fn foo(&self, a: u32) -> u32;
fn bar(&self, a: u32) -> u32;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert_eq!(wrapper.foo(1), 1);
assert_eq!(wrapper.bar(2), 2);
}
#[test]
fn test_segment_try_into() {
struct A;
#[derive(Debug, PartialEq)]
struct B;
impl TryFrom<A> for B {
type Error = u32;
fn try_from(_value: A) -> Result<Self, Self::Error> {
Ok(B)
}
}
struct Inner;
impl Inner {
pub fn method(&self) -> A {
A
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
#[try_into]
to self.inner {
fn method(&self) -> Result<B, u32>;
}
}
}
let wrapper = Wrapper { inner: Inner };
let wrapper = Wrapper { inner: Inner };
assert_eq!(wrapper.method(), Ok(B));
}
#[test]
fn test_segment_into() {
struct A(u32);
impl From<A> for Result<u32, ()> {
fn from(value: A) -> Self {
Ok(value.0)
}
}
impl From<A> for u64 {
fn from(value: A) -> Self {
value.0 as u64
}
}
struct Inner;
impl Inner {
pub fn method(&self) -> A {
A(0)
}
}
struct Wrapper {
inner: Inner,
}
impl Wrapper {
delegate! {
#[into(Result<u32, ()>)]
to self.inner {
#[unwrap]
fn method(&self) -> u32;
#[into]
#[call(method)]
fn method2(&self) -> u64;
}
}
}
let wrapper = Wrapper { inner: Inner };
assert_eq!(wrapper.method(), 0);
assert_eq!(wrapper.method2(), 0);
}
#[test]
fn test_segment_await() {
struct UserRepo;
impl UserRepo {
fn foo(&self) {}
async fn bar(&self) -> u32 {
1
}
}
struct SharedRepo(tokio::sync::Mutex<UserRepo>);
impl SharedRepo {
delegate! {
#[await(false)]
to self.0.lock().await {
async fn foo(&self);
#[await(true)]
async fn bar(&self) -> u32;
}
}
}
}
#[test]
fn test_segment_through_trait() {
trait A {
fn f(&self) -> u32;
}
trait B {
fn f(&self) -> u32;
}
struct Foo;
impl A for Foo {
fn f(&self) -> u32 {
0
}
}
impl B for Foo {
fn f(&self) -> u32 {
1
}
}
struct Bar(Foo);
impl Bar {
delegate! {
#[through(A)]
to &self.0 {
fn f(&self) -> u32;
#[call(f)]
#[through(B)]
fn f2(&self) -> u32;
}
}
}
let bar = Bar(Foo);
assert_eq!(bar.f(), 0);
assert_eq!(bar.f2(), 1);
}
#[test]
fn test_segment_inline() {
struct Foo;
impl Foo {
fn f(&self) -> u32 {
0
}
}
struct Bar(Foo);
impl Bar {
delegate! {
#[inline(always)]
to self.0 {
fn f(&self) -> u32;
}
}
}
let bar = Bar(Foo);
assert_eq!(bar.f(), 0);
}
#[test]
fn test_attribute_with_path() {
struct Foo;
impl Foo {
fn f(&self) -> u32 {
0
}
}
struct Bar(Foo);
impl Bar {
delegate! {
#[diagnostic::on_unimplemented]
to self.0 {
fn f(&self) -> u32;
}
}
}
let bar = Bar(Foo);
assert_eq!(bar.f(), 0);
}
================================================
FILE: tests/stack.rs
================================================
use delegate::delegate;
#[derive(Clone, Debug)]
struct Stack<T> {
inner: Vec<T>,
}
impl<T> Stack<T> {
/// Allocate an empty stack
pub fn new() -> Stack<T> {
Stack { inner: vec![] }
}
delegate! {
to self.inner {
#[inline(never)]
#[call(len)]
pub(crate) fn size(&self) -> usize;
/// doc comment
fn is_empty(&self) -> bool;
#[inline(never)]
fn push(&mut self, v: T);
pub fn pop(&mut self) -> Option<T>;
#[call(last)]
#[inline(never)]
fn peek(&self) -> Option<&T>;
fn clear(&mut self);
fn into_boxed_slice(self) -> Box<[T]>;
}
}
}
#[test]
fn test_stack() {
let mut stack: Stack<u32> = Stack::new();
assert_eq!(stack.size(), 0);
assert_eq!(stack.is_empty(), true);
assert_eq!(stack.peek(), None);
stack.clear();
assert_eq!(stack.size(), 0);
assert_eq!(stack.is_empty(), true);
assert_eq!(stack.peek(), None);
assert_eq!(stack.pop(), None);
assert_eq!(stack.size(), 0);
assert_eq!(stack.is_empty(), true);
assert_eq!(stack.peek(), None);
stack.push(1);
assert_eq!(stack.size(), 1);
assert_eq!(stack.is_empty(), false);
assert_eq!(stack.peek(), Some(&1));
assert_eq!(stack.pop(), Some(1));
assert_eq!(stack.size(), 0);
assert_eq!(stack.is_empty(), true);
assert_eq!(stack.peek(), None);
stack.push(1);
stack.push(2);
stack.push(3);
assert_eq!(stack.size(), 3);
assert_eq!(stack.is_empty(), false);
assert_eq!(stack.peek(), Some(&3));
assert_eq!(stack.clone().into_boxed_slice().into_vec(), stack.inner);
assert_eq!(stack.pop(), Some(3));
assert_eq!(stack.size(), 2);
assert_eq!(stack.is_empty(), false);
assert_eq!(stack.peek(), Some(&2));
stack.clear();
assert_eq!(stack.size(), 0);
assert_eq!(stack.is_empty(), true);
assert_eq!(stack.peek(), None);
}
================================================
FILE: tests/through_trait.rs
================================================
use delegate::delegate;
#[test]
fn test_call_through_trait() {
trait A {
fn f(&self) -> u32;
}
trait B {
fn f(&self) -> u32;
}
struct Foo;
impl A for Foo {
fn f(&self) -> u32 {
0
}
}
impl B for Foo {
fn f(&self) -> u32 {
1
}
}
struct Bar(Foo);
impl Bar {
delegate! {
to &self.0 {
#[through(A)]
fn f(&self) -> u32;
#[call(f)]
#[through(B)]
fn f2(&self) -> u32;
}
}
}
let bar = Bar(Foo);
assert_eq!(bar.f(), 0);
assert_eq!(bar.f2(), 1);
}
gitextract_6vrwi07n/
├── .github/
│ ├── FUNDING.yml
│ └── workflows/
│ ├── nightly-build.yml
│ ├── publish.yml
│ └── test.yml
├── .gitignore
├── .release-plz.toml
├── CHANGELOG.md
├── Cargo.toml
├── LICENSE-APACHE
├── LICENSE-MIT
├── README.md
├── src/
│ ├── attributes.rs
│ └── lib.rs
└── tests/
├── argument_modifier.rs
├── associated_const_delegation.rs
├── async_await.rs
├── closure.rs
├── delegate_to_enum.rs
├── delegation.rs
├── expand/
│ ├── fields.expanded.rs
│ └── fields.rs
├── expr.rs
├── expr_attribute.rs
├── fields.rs
├── function.rs
├── generic.rs
├── in_macro_expansion.rs
├── inline_args.rs
├── nested.rs
├── returntype.rs
├── segment_attributes.rs
├── stack.rs
└── through_trait.rs
SYMBOL INDEX (148 symbols across 22 files)
FILE: src/attributes.rs
type CallMethodAttribute (line 8) | pub struct CallMethodAttribute {
method parse (line 13) | fn parse(input: ParseStream) -> Result<Self, Error> {
type GetFieldAttribute (line 21) | pub struct GetFieldAttribute {
method reference_tokens (line 27) | pub fn reference_tokens(&self) -> Option<TokenStream> {
method parse (line 36) | fn parse(input: ParseStream) -> Result<Self, Error> {
type GenerateAwaitAttribute (line 49) | struct GenerateAwaitAttribute {
method parse (line 54) | fn parse(input: ParseStream) -> Result<Self, Error> {
type IntoAttribute (line 61) | struct IntoAttribute {
method parse (line 66) | fn parse(input: ParseStream) -> Result<Self, Error> {
type AssociatedConstant (line 80) | pub struct AssociatedConstant {
method parse (line 86) | fn parse(input: ParseStream) -> Result<Self, Error> {
type ExprPlaceHolder (line 119) | pub struct ExprPlaceHolder;
method parse (line 122) | fn parse(input: ParseStream) -> syn::Result<Self> {
type Placeholder (line 130) | enum Placeholder {
type TemplateToken (line 140) | enum TemplateToken {
method replace (line 148) | fn replace(&self, replacement: &TokenStream) -> TokenStream {
type TemplateExpr (line 166) | pub struct TemplateExpr {
method parse (line 173) | fn parse(input: ParseStream) -> syn::Result<Self> {
method expand_template (line 202) | pub fn expand_template(&self, replacement: &TokenStream) -> TokenStream {
type TraitTarget (line 210) | pub struct TraitTarget {
method parse (line 215) | fn parse(input: ParseStream) -> Result<Self, Error> {
type ReturnExpression (line 228) | pub enum ReturnExpression {
type TargetSpecifier (line 234) | pub enum TargetSpecifier {
method get_member (line 240) | pub fn get_member(&self, default: &syn::Ident) -> syn::Member {
type ParsedAttribute (line 252) | enum ParsedAttribute {
function parse_attributes (line 261) | fn parse_attributes(
type MethodAttributes (line 360) | pub struct MethodAttributes<'a> {
function parse_method_attributes (line 378) | pub fn parse_method_attributes<'a>(
type SegmentAttributes (line 456) | pub struct SegmentAttributes {
function parse_segment_attributes (line 464) | pub fn parse_segment_attributes(attrs: &[Attribute]) -> SegmentAttributes {
function combine_attributes (line 511) | pub fn combine_attributes<'a>(
FILE: src/lib.rs
type ArgumentModifier (line 502) | enum ArgumentModifier {
type DelegatedInput (line 509) | enum DelegatedInput {
method parse (line 539) | fn parse(input: ParseStream) -> Result<Self, Error> {
function get_argument_modifier (line 517) | fn get_argument_modifier(attribute: syn::Attribute) -> Result<ArgumentMo...
type DelegatedMethod (line 569) | struct DelegatedMethod {
method parse (line 628) | fn parse(input: ParseStream) -> Result<Self, Error> {
function parse_input_into_argument_expression (line 579) | fn parse_input_into_argument_expression(
type DelegatedSegment (line 807) | struct DelegatedSegment {
method parse (line 814) | fn parse(input: ParseStream) -> Result<Self, Error> {
type DelegationBlock (line 846) | struct DelegationBlock {
method parse (line 851) | fn parse(input: ParseStream) -> Result<Self, Error> {
function has_inline_attribute (line 862) | fn has_inline_attribute(attrs: &[&syn::Attribute]) -> bool {
type MatchVisitor (line 872) | struct MatchVisitor<F>(F);
method visit_arm_mut (line 875) | fn visit_arm_mut(&mut self, arm: &mut syn::Arm) {
function delegate (line 882) | pub fn delegate(tokens: TokenStream) -> TokenStream {
function tolerant_outer_attributes (line 1092) | fn tolerant_outer_attributes(input: ParseStream) -> syn::Result<Vec<syn:...
FILE: tests/argument_modifier.rs
type MyNewU32 (line 3) | struct MyNewU32(u32);
type Foo (line 5) | trait Foo {
method bar (line 6) | fn bar(&self, x: Self);
method bar (line 10) | fn bar(&self, x: Self) {}
function from (line 14) | fn from(value: MyNewU32) -> Self {
type Bar (line 27) | struct Bar {
type Baz (line 42) | struct Baz(Vec<u32>);
FILE: tests/associated_const_delegation.rs
function test_delegate_constant (line 5) | fn test_delegate_constant() {
function multiple_consts (line 52) | fn multiple_consts() {
FILE: tests/async_await.rs
function test_async_await (line 9) | fn test_async_await() {
function test_async_trait (line 44) | fn test_async_trait() {
function test_bridge_async_to_sync (line 87) | fn test_bridge_async_to_sync() {
function test_bridge_sync_to_async (line 106) | fn test_bridge_sync_to_async() {
FILE: tests/closure.rs
function test_delegate_closure (line 5) | fn test_delegate_closure() {
function test_delegate_closure_associated_function (line 46) | fn test_delegate_closure_associated_function() {
FILE: tests/delegate_to_enum.rs
type Enum (line 3) | enum Enum {
type A (line 9) | struct A {
method dbg_inner (line 14) | fn dbg_inner(&self) -> usize {
method into_num (line 19) | fn into_num(&self) -> u8 {
type B (line 23) | struct B {
method dbg_inner (line 28) | fn dbg_inner(&self) -> usize {
method into_num (line 33) | fn into_num(&self) -> u64 {
type C (line 38) | struct C {
method dbg_inner (line 43) | fn dbg_inner(&self) -> usize {
method into_num (line 48) | fn into_num(&self) -> usize {
type IntoUsize (line 69) | struct IntoUsize(usize);
method from (line 72) | fn from(value: usize) -> Self {
method from (line 77) | fn from(value: u64) -> Self {
method from (line 82) | fn from(value: u8) -> Self {
function test_delegate_enum_method (line 88) | fn test_delegate_enum_method() {
function test_delegate_enum_into (line 102) | fn test_delegate_enum_into() {
FILE: tests/delegation.rs
function test_expansions (line 4) | fn test_expansions() {
function test_delegation (line 9) | fn test_delegation() {
function test_delegate_self (line 74) | fn test_delegate_self() {
function test_delegate_tuple (line 100) | fn test_delegate_tuple() {
FILE: tests/expand/fields.expanded.rs
type Datum (line 2) | struct Datum {
type DatumWrapper (line 7) | struct DatumWrapper(Datum);
method get_inner (line 9) | fn get_inner(&self) -> &Datum {
method value (line 14) | fn value(&self) -> u32 {
method renamed_value (line 19) | fn renamed_value(&self) -> u32 {
method renamed_value_ref (line 24) | fn renamed_value_ref(&self) -> &u32 {
method renamed_value_ref_mut (line 29) | fn renamed_value_ref_mut(&mut self) -> &mut u32 {
method error (line 34) | fn error(&self) -> &u32 {
method x (line 39) | fn x(&self) -> f32 {
method y (line 44) | fn y(&self) -> &f32 {
method value_ref_via_get_inner (line 49) | fn value_ref_via_get_inner(&self) -> &u32 {
FILE: tests/expand/fields.rs
type Datum (line 4) | struct Datum {
type DatumWrapper (line 10) | struct DatumWrapper(Datum);
method get_inner (line 13) | fn get_inner(&self) -> &Datum {
FILE: tests/expr.rs
type Inner (line 4) | struct Inner;
method method (line 6) | pub fn method(&self, num: u32) -> u32 {
method method2 (line 9) | pub fn method2(&self, num: u32) -> u32 {
type Wrapper (line 14) | struct Wrapper {
function global_fn (line 18) | fn global_fn() -> Inner {
function test_mutex (line 34) | fn test_mutex() {
function test_index (line 44) | fn test_index() {
FILE: tests/expr_attribute.rs
function delegate_with_custom_expr (line 5) | fn delegate_with_custom_expr() {
function delegate_without_placeholder (line 32) | fn delegate_without_placeholder() {
FILE: tests/fields.rs
type Datum (line 3) | struct Datum {
type DatumWrapper (line 9) | struct DatumWrapper(Datum);
method get_inner (line 12) | fn get_inner(&self) -> &Datum {
function test_fields (line 54) | fn test_fields() {
FILE: tests/function.rs
function test_delegate_function (line 4) | fn test_delegate_function() {
FILE: tests/generic.rs
function test_generics_method (line 6) | fn test_generics_method() {
function test_generics_function (line 23) | fn test_generics_function() {
function test_generics_through_trait (line 40) | fn test_generics_through_trait() {
function test_generics_complex (line 69) | fn test_generics_complex() {
function test_lifetime_late_bound (line 86) | fn test_lifetime_late_bound() {
FILE: tests/in_macro_expansion.rs
type Trait (line 7) | trait Trait {
method method_to_delegate (line 8) | fn method_to_delegate(&self) -> bool;
method method_to_delegate (line 13) | fn method_to_delegate(&self) -> bool {
type Struct1 (line 11) | struct Struct1();
type Struct2 (line 18) | struct Struct2(pub Struct1);
function test (line 37) | fn test() {
FILE: tests/inline_args.rs
function test_inline_args (line 4) | fn test_inline_args() {
function test_mixed_args (line 61) | fn test_mixed_args() {
FILE: tests/nested.rs
type Inner (line 3) | struct Inner;
method method (line 5) | pub fn method(&self, num: u32) -> u32 {
type Inner2 (line 10) | struct Inner2 {
type Wrapper (line 14) | struct Wrapper {
function test_nested (line 27) | fn test_nested() {
FILE: tests/returntype.rs
function test_generic_returntype (line 5) | fn test_generic_returntype() {
function test_into (line 41) | fn test_into() {
function test_try_into (line 72) | fn test_try_into() {
function test_try_into_unwrap (line 112) | fn test_try_into_unwrap() {
function test_unwrap_result (line 153) | fn test_unwrap_result() {
function test_unwrap_option (line 180) | fn test_unwrap_option() {
function test_unwrap_no_return (line 208) | fn test_unwrap_no_return() {
function test_unwrap_into (line 234) | fn test_unwrap_into() {
function test_into_unwrap (line 270) | fn test_into_unwrap() {
FILE: tests/segment_attributes.rs
function test_segment_unwrap (line 5) | fn test_segment_unwrap() {
function test_segment_try_into (line 37) | fn test_segment_try_into() {
function test_segment_into (line 78) | fn test_segment_into() {
function test_segment_await (line 125) | fn test_segment_await() {
function test_segment_through_trait (line 149) | fn test_segment_through_trait() {
function test_segment_inline (line 191) | fn test_segment_inline() {
function test_attribute_with_path (line 216) | fn test_attribute_with_path() {
FILE: tests/stack.rs
type Stack (line 4) | struct Stack<T> {
function new (line 10) | pub fn new() -> Stack<T> {
function test_stack (line 37) | fn test_stack() {
FILE: tests/through_trait.rs
function test_call_through_trait (line 4) | fn test_call_through_trait() {
Condensed preview — 33 files, each showing path, character count, and a content snippet. Download the .json file or copy for the full structured content (140K chars).
[
{
"path": ".github/FUNDING.yml",
"chars": 15,
"preview": "github: Kobzol\n"
},
{
"path": ".github/workflows/nightly-build.yml",
"chars": 629,
"preview": "on:\n schedule:\n - cron: \"0 0 * * *\"\n workflow_dispatch:\n\nname: Nightly Build\n\njobs:\n test:\n name: Build\n run"
},
{
"path": ".github/workflows/publish.yml",
"chars": 1811,
"preview": "name: Publish new release\n\non:\n push:\n branches:\n - main\n\njobs:\n test:\n name: Release test\n runs-on: ubu"
},
{
"path": ".github/workflows/test.yml",
"chars": 1253,
"preview": "# Based on https://github.com/actions-rs/meta/blob/master/recipes/matrix.md\n\non: [ push, pull_request ]\n\nname: Tests\n\njo"
},
{
"path": ".gitignore",
"chars": 30,
"preview": "/target\n**/*.rs.bk\nCargo.lock\n"
},
{
"path": ".release-plz.toml",
"chars": 110,
"preview": "[workspace]\nrelease_always = false\npr_branch_prefix = \"release-\"\npr_labels = [\"release\"]\nsemver_check = false\n"
},
{
"path": "CHANGELOG.md",
"chars": 6964,
"preview": "# Changelog\n\nAll notable changes to this project will be documented in this file.\n\nThe format is based on [Keep a Change"
},
{
"path": "Cargo.toml",
"chars": 643,
"preview": "[package]\nname = \"delegate\"\ndescription = \"Method delegation with less boilerplate\"\nversion = \"0.13.5\"\nauthors = [\"Godfr"
},
{
"path": "LICENSE-APACHE",
"chars": 11357,
"preview": " Apache License\n Version 2.0, January 2004\n "
},
{
"path": "LICENSE-MIT",
"chars": 1078,
"preview": "Copyright (c) 2018 The Rust Delegate Crate Developers\n\nPermission is hereby granted, free of charge, to any\nperson obtai"
},
{
"path": "README.md",
"chars": 12911,
"preview": "# Method delegation with less boilerplate\n\n[![Build Status](https://github.com/kobzol/rust-delegate/workflows/Tests/badg"
},
{
"path": "src/attributes.rs",
"chars": 19176,
"preview": "use proc_macro2::{Delimiter, TokenStream, TokenTree};\nuse quote::ToTokens;\nuse std::collections::VecDeque;\nuse std::ops:"
},
{
"path": "src/lib.rs",
"chars": 41107,
"preview": "//! This crate removes some boilerplate for structs that simply delegate\n//! some of their methods to one or more of the"
},
{
"path": "tests/argument_modifier.rs",
"chars": 715,
"preview": "use delegate::delegate;\n\nstruct MyNewU32(u32);\n\ntrait Foo {\n fn bar(&self, x: Self);\n}\n\nimpl Foo for u32 {\n fn bar"
},
{
"path": "tests/associated_const_delegation.rs",
"chars": 1561,
"preview": "extern crate delegate;\nuse delegate::delegate;\n\n#[test]\nfn test_delegate_constant() {\n trait WithConst {\n cons"
},
{
"path": "tests/async_await.rs",
"chars": 2897,
"preview": "extern crate delegate;\n\nuse delegate::delegate;\nuse std::future::Future;\nuse std::pin::Pin;\nuse std::task::{Context, Pol"
},
{
"path": "tests/closure.rs",
"chars": 1669,
"preview": "use delegate::delegate;\nuse std::cell::OnceCell;\n\n#[test]\nfn test_delegate_closure() {\n struct Inner(u32);\n impl I"
},
{
"path": "tests/delegate_to_enum.rs",
"chars": 1891,
"preview": "use delegate::delegate;\n\nenum Enum {\n A(A),\n B(B),\n C { v: C },\n}\n\nstruct A {\n val: usize,\n}\n\nimpl A {\n f"
},
{
"path": "tests/delegation.rs",
"chars": 2556,
"preview": "use delegate::delegate;\n\n#[test]\nfn test_expansions() {\n macrotest::expand(\"tests/expand/*.rs\");\n}\n\n#[test]\nfn test_d"
},
{
"path": "tests/expand/fields.expanded.rs",
"chars": 1260,
"preview": "use delegate::delegate;\nstruct Datum {\n value: u32,\n error: u32,\n xy: (f32, f32),\n}\nstruct DatumWrapper(Datum);"
},
{
"path": "tests/expand/fields.rs",
"chars": 1380,
"preview": "\nuse delegate::delegate;\n\nstruct Datum {\n value: u32,\n error: u32,\n xy: (f32, f32)\n}\n\nstruct DatumWrapper(Datum"
},
{
"path": "tests/expr.rs",
"chars": 1206,
"preview": "use delegate::delegate;\nuse std::sync::Mutex;\n\nstruct Inner;\nimpl Inner {\n pub fn method(&self, num: u32) -> u32 {\n "
},
{
"path": "tests/expr_attribute.rs",
"chars": 1018,
"preview": "extern crate delegate;\nuse delegate::delegate;\n\n#[test]\nfn delegate_with_custom_expr() {\n struct A(Vec<u8>);\n\n imp"
},
{
"path": "tests/fields.rs",
"chars": 1946,
"preview": "use delegate::delegate;\n\nstruct Datum {\n value: u32,\n error: u32,\n xy: (f32, f32),\n}\n\nstruct DatumWrapper(Datum"
},
{
"path": "tests/function.rs",
"chars": 328,
"preview": "use delegate::delegate;\n\n#[test]\nfn test_delegate_function() {\n struct A {}\n impl A {\n fn foo(a: u32) -> u3"
},
{
"path": "tests/generic.rs",
"chars": 1862,
"preview": "use delegate::delegate;\nuse std::collections::HashSet;\nuse std::hash::Hash;\n\n#[test]\nfn test_generics_method() {\n str"
},
{
"path": "tests/in_macro_expansion.rs",
"chars": 905,
"preview": "///\n/// Tests that a macro can expand into a delegate block,\n/// where the target comes from a macro variable.\n///\nuse d"
},
{
"path": "tests/inline_args.rs",
"chars": 2346,
"preview": "use delegate::delegate;\n\n#[test]\nfn test_inline_args() {\n struct Inner;\n\n impl Inner {\n fn fun_generic<S: C"
},
{
"path": "tests/nested.rs",
"chars": 474,
"preview": "use delegate::delegate;\n\nstruct Inner;\nimpl Inner {\n pub fn method(&self, num: u32) -> u32 {\n num\n }\n}\n\nstr"
},
{
"path": "tests/returntype.rs",
"chars": 5225,
"preview": "use delegate::delegate;\nuse std::convert::TryFrom;\n\n#[test]\nfn test_generic_returntype() {\n trait TestTrait {\n "
},
{
"path": "tests/segment_attributes.rs",
"chars": 4115,
"preview": "use delegate::delegate;\nuse std::convert::TryFrom;\n\n#[test]\nfn test_segment_unwrap() {\n struct Inner;\n\n impl Inner"
},
{
"path": "tests/stack.rs",
"chars": 2014,
"preview": "use delegate::delegate;\n\n#[derive(Clone, Debug)]\nstruct Stack<T> {\n inner: Vec<T>,\n}\n\nimpl<T> Stack<T> {\n /// Allo"
},
{
"path": "tests/through_trait.rs",
"chars": 696,
"preview": "use delegate::delegate;\n\n#[test]\nfn test_call_through_trait() {\n trait A {\n fn f(&self) -> u32;\n }\n\n tra"
}
]
About this extraction
This page contains the full source code of the chancancode/rust-delegate GitHub repository, extracted and formatted as plain text for AI agents and large language models (LLMs). The extraction includes 33 files (130.0 KB), approximately 32.1k tokens, and a symbol index with 148 extracted functions, classes, methods, constants, and types. Use this with OpenClaw, Claude, ChatGPT, Cursor, Windsurf, or any other AI tool that accepts text input. You can copy the full output to your clipboard or download it as a .txt file.
Extracted by GitExtract — free GitHub repo to text converter for AI. Built by Nikandr Surkov.