https://github.com/mintlu8/default-constructor
Macros for creating pseudo-dsls that constructs structs through default construction and field conversion.
https://github.com/mintlu8/default-constructor
Last synced: about 1 year ago
JSON representation
Macros for creating pseudo-dsls that constructs structs through default construction and field conversion.
- Host: GitHub
- URL: https://github.com/mintlu8/default-constructor
- Owner: mintlu8
- License: apache-2.0
- Created: 2024-04-17T20:03:52.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2024-06-08T12:49:21.000Z (about 2 years ago)
- Last Synced: 2024-06-12T16:37:05.522Z (about 2 years ago)
- Language: Rust
- Size: 24.4 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE-APACHE
Awesome Lists containing this project
README
# default-constructor
Macros for creating pseudo-dsls that constructs structs through
default construction and field conversion.
## Motivation
This crates is primary designed for `bevy` where constructing large bundles
with `..Default::default()` is common.
## Syntax
Take `construct!` that uses `Into`.
```rust
construct! {
Student {
name: "Timmy",
age: 10,
father: Parent {
name: "Tommy",
age: 42
}
}
}
```
This expands to
```rust
Student {
name: Into::into("Timmy"),
age: Into::into(10),
father: construct! {
Parent {
name: "Tommy",
age: 42
}
}
..Default::default()
}
```
The macro is recursive on nested struct declarations,
if the behavior is not desired, wrap nested structs in brackets.
```rust
construct! {
Student {
name: "Timmy",
age: 10,
father: { Parent {
name: "Tommy",
age: 42
}}
}
}
```
## Tuple Construction
To create a tuple, concatenate multiple structs with comma.
```rust
construct! {
Student {
name: "Timmy",
age: 10,
},
Son::<2> {
of: "Tommy"
},
Age(16),
}
```
## Meta Constructor
The meta constructor macro allows you to define your own macro with
custom configurations.
See documentation on `meta_default_constructor!` for details.
## `InferInto`
InferInto allows the user to bypass the orphan rule to create conversions.
By default we provide `i32` (integer literal) to all numeric types
and `i64` -> `f64` in addition to the standard `From` and `Into`.
If multiple conversion paths are found, the conversion will fail,
thus failing the `infer_construct` macro.
## ChangeLog
* 0.4
* `meta_default_constructor` no longer takes a list of imports as the first argument.
* `meta_default_constructor` can now create tuples by chaining with comma.
* 0.5
Made changes to fit `bevy 0.15`'s patterns.
* No longer treats `Ident` as `Ident::default()`.
* No longer treats snake case functions as structs.
* All non-struct patterns falls through the macro.
## License
License under either of
Apache License, Version 2.0 (LICENSE-APACHE or )
MIT license (LICENSE-MIT or )
at your option.
## Contribution
Contributions are welcome!
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.