kozo provides some syntax sugars to use Rust's struct easily.\
Current kozo provides following 2 proc macros:
- `define!`
- `retrieve!`
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<br/>
# define!
`define!` macro enables to define nested structs in a way easy to see.
```rs
use kozo::define;
define!(struct NestedStruct {
a: Vec<u8>,
b: struct B {
c: struct C {
d: u8,
e: u8,
},
f: enum F {
X,
Y,
Other {
name: String,
id: usize
},
},
},
});
fn main() {
let sample = NestedStruct {
a: vec![1, 1, 0, 1, 0, 1, 1],
b: B {
c: C {
d: 0,
e: 1,
},
f: F::X,
},
};
println!("{}", sample.b.c.d); // 0
}
```
( examples/define_sample.rs )
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Then, `define!` is **just a syntax sugar** of defining each named structs separately like
```rs
struct DeepNestedStruct {
a: Vec<u8>,
b: B,
}
struct B {
c: C,
f: F,
}
struct C {
d: u8,
e: u8,
}
enum F {
X,
Y,
Other {
name: String,
id: usize,
},
}
```
So please pay attension to that **all structs declared in define!(); are visible** in its scope.
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<br/>
# retrieve!
`retrieve!` enables to simply get more than 1 value from a struct:
```rs
use kozo::{define, retrieve};
define!(struct Sample {
a: u8,
b: struct B {
c: String,
d: Vec<u8>,
},
});
fn main() {
let s = Sample {
a: 0,
b: B {
c: "I have an apple?".into(),
d: vec![1, 1, 0, 1, 0, 1, 1],
},
};
retrieve!(a, b from s);
println!("{a}"); // 0,
println!("{}", b.c);
}
```
( examples/retrieve_sample.rs )
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### NOTICEs
In next version (v0.2),
- `define!` will be able to accept `derive`s.
```rs
#[derive(Clone)]
define!(struct S {
// ...
})
```
- `retrieve!` will be able to get nested values directly like
```rs
let s = Sample {
a: 0,
b: B {
c: "You have an apple!".into(),
d: vec![1, 1, 0, 1, 0, 1, 1,],
},
};
retrieve!(a, c(b), from s);
```
<br/>
In future, `retrieve!` will support named retrieving:
```rs
let s = Sample {
a: 0,
b: B {
c: "Is this an apple?".into(),
d: vec![1, 1, 0, 1, 0, 1, 1,],
},
};
retrieve!(var1 @ a, crazy_apple_man @ c(b), from s);
println!("{var1}"); // 0
```
<br/>
for Japanese speakers...\
"kozo" は「小僧」の発音で読んでください。struct「構造」と掛けたネーミングで、構造体に関する小さく便利な機能を提供するクレートという意味を込めています。