Rust宏可以创建新的标识符吗? [英] Can a Rust macro create new identifiers?

问题描述

我想创建一个setter/getter函数对，它们的名称是基于共享组件自动生成的，但是我找不到宏规则生成新名称的任何示例.

I'd like to create a setter/getter pair of functions where the names are automatically generated based on a shared component, but I couldn't find any example of macro rules generating a new name.

是否可以生成类似fn get_$iden()和SomeEnum::XX_GET_$enum_iden的代码?

Is there a way to generate code like fn get_$iden() and SomeEnum::XX_GET_$enum_iden?

推荐答案

我的 mashup > 条板箱提供了一种稳定的方式来创建可用于任何Rust版本> = 1.15.0的新标识符.

My mashup crate provides a stable way to create new identifiers that works with any Rust version >= 1.15.0.

#[macro_use]
extern crate mashup;

macro_rules! make_a_struct_and_getters {
    ($name:ident { $($field:ident),* }) => {
        // Define the struct. This expands to:
        //
        //     pub struct S {
        //         a: String,
        //         b: String,
        //         c: String,
        //     }
        pub struct $name {
            $(
                $field: String,
            )*
        }

        // Use mashup to define a substitution macro `m!` that replaces every
        // occurrence of the tokens `"get" $field` in its input with the
        // concatenated identifier `get_ $field`.
        mashup! {
            $(
                m["get" $field] = get_ $field;
            )*
        }

        // Invoke the substitution macro to build an impl block with getters.
        // This expands to:
        //
        //     impl S {
        //         pub fn get_a(&self) -> &str { &self.a }
        //         pub fn get_b(&self) -> &str { &self.b }
        //         pub fn get_c(&self) -> &str { &self.c }
        //     }
        m! {
            impl $name {
                $(
                    pub fn "get" $field(&self) -> &str {
                        &self.$field
                    }
                )*
            }
        }
    }
}

make_a_struct_and_getters!(S { a, b, c });

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