Macro Tools

contain some useful macro tools;

Field

create field read and write method for field

for example

create read field for Meta;

    #[derive(Fields)]
    #[r]
    struct Meta {
        field_a: String,
        field_b: i32,
    }

    let meta = Meta {
        field_a: String::new(),
        field_b: 3,
    };

    let field_a: &String = meta.field_a();
    let field_b: i32 = meta.field_b();

create common write field for struct

    #[derive(Fields)]
    #[w]
    struct Meta {
        field_a: String,
        field_b: i32,
    }

    let mut meta = Meta {
        field_a: String::new(),
        field_b: 3,
    };

    let field_a_mut: &mut String = meta.field_a_mut();
    let field_b_mut: &mut i32 = meta.field_b_mut();

custom write field for struct with reducer: impl FnOnce(Type) -> Type

    #[derive(Fields)]
    #[r]
    struct Meta {
        #[w(reducer)]
        field_a: String,
        field_b: i32,
    }

    let mut meta = Meta {
        field_a: String::new(),
        field_b: 3,
    };

    let field_b = meta.field_b();

    meta.set_field_a(|field_a| field_a + &field_b.to_string());

custom write field for struct with set

    #[derive(Fields)]
    #[r]
    struct Meta {
        #[w(set)]
        field_a: String,
        field_b: i32,
    }

    let mut meta = Meta {
        field_a: String::new(),
        field_b: 3,
    };

    let field_b = meta.field_b();

    meta.set_field_a(meta.field_a().clone() + &field_b.to_string());

visibility of Fields

if struct is defined as pub then all field method will be pub

if struct is defined as private then all field method will be private

or custom vis for field method

mod private {
    use picea_macro_tools::Fields;

    #[derive(Fields)]
    #[r]
    pub struct Meta {
        #[w(set, vis(pub(self)))]
        field_a: String,
        field_b: i32,
    }
}

/// follow code will not compile
let mut meta = private::Meta::new();

meta.set_field_a(""); // function `set_field_a` is private