1 unstable release
0.1.0 | Nov 4, 2023 |
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#2 in #destruct
7KB
About
obstruct
is an experimental implementation of anonymous structs and named arguments for Rust.
Anonymous structs
Create an anonymous struct with instruct!
and destructure it with destruct!
:
#![feature(associated_const_equality)]
use obstruct::{instruct, destruct};
// Create an anonymous struct.
let structured = instruct! { red: 0, green: 1.0, blue: 2 };
// Destructure that struct.
destruct! { let {red, green, blue} = structured };
assert_eq!(red, 0);
assert_eq!(green, 1.0);
assert_eq!(blue, 2);
Note that this is not (just) a tuple: the order in which fields are specified does not matter!
#![feature(associated_const_equality)]
use obstruct::{instruct, destruct};
// Create an anonymous struct.
let structured = instruct! { red: 0, green: 1.0, blue: 2 };
// Destructure that struct.
destruct! { let {blue, green, red} = structured };
assert_eq!(red, 0);
assert_eq!(green, 1.0);
assert_eq!(blue, 2);
If you attempt to access a field that doesn't exist, you will get a compile-time error:
#![feature(associated_const_equality)]
use obstruct::{instruct, destruct};
// Create an anonymous struct.
let structured = instruct! { red: 0, green: 1.0, blue: 2 };
// Destructure that struct.
destruct! { let {blue, green, oops} = structured };
// ^^^ --- will fail with a complex error message pointing at `oops`.
Named arguments
Create a function accepting named parameters with destruct!
and call it with call!
:
#![feature(associated_const_equality)]
use obstruct::{call, instruct, destruct};
// Create a function accepting anonymous arguments.
destruct!(fn do_something({red: u8, green: &'static str, blue: ()}) {
println!("Roses are {red}");
});
// Call this function
call!(do_something, {red: 0, green: "GREEN", blue: ()});
// Or equivalently
do_something(instruct! {red: 0, green: "GREEN", blue: ()});
Again, the order in which arguments are specified does not matter:
#![feature(associated_const_equality)]
use obstruct::{call, instruct, destruct};
// Create a function accepting anonymous arguments.
destruct!(fn do_something({red: u8, green: &'static str, blue: ()}) {
println!("Roses are {red}");
});
do_something(instruct! {blue: (), green: "GREEN", red: 0});
Again, errors are caught at compile-time:
#![feature(associated_const_equality)]
use obstruct::{call, instruct, destruct};
// Create a function accepting anonymous arguments.
destruct!(fn do_something({red: u8, green: &'static str, blue: ()}) {
println!("Roses are {red}");
});
do_something(instruct! {blue: (), green: "GREEN", oops: 0});
// ^^^ --- will fail with a complex error message pointing at `oops`.
call!(do_something, {red: 0, green: "GREEN", oops: ()});
// ^^^ --- will fail with a complex error message pointing at `oops`.
Dependencies
~1.5–9MB
~81K SLoC