Rust
사용자 지정 파생 : "매크로 1.1"
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소개
Rust 1.15는 새로운 기능을 추가 (안정화)했습니다 : Custom은 Macros 1.1을 따릅니다.
이제는 일반적인 PartialEq
또는 Debug
와 별개로 #[deriving(MyOwnDerive)]
가질 수 있습니다. 이 기능의 주요 사용자는 serde 와 diesel 입니다.
녹슨 책 링크 : https://doc.rust-lang.org/stable/book/procedural-macros.html
장황한 helloworld
Cargo.toml :
[package] name = "customderive" version = "0.1.1" [lib] proc-macro=true [dependencies] quote="^0.3.12" syn="^0.11.4"
src / lib.rs :
#![crate_type = "proc-macro"] extern crate proc_macro; use proc_macro::TokenStream; extern crate syn; #[macro_use] extern crate quote; #[proc_macro_derive(Hello)] pub fn qqq(input: TokenStream) -> TokenStream { let source = input.to_string(); println!("Normalized source code: {}", source); let ast = syn::parse_derive_input(&source).unwrap(); println!("Syn's AST: {:?}", ast); // {:#?} - pretty print let struct_name = &ast.ident; let quoted_code = quote!{ fn hello() { println!("Hello, {}!", stringify!(#struct_name)); } }; println!("Quoted code: {:?}", quoted_code); quoted_code.parse().unwrap() }
examples / hello.rs :
#[macro_use] extern crate customderive; #[derive(Hello)] struct Qqq; fn main(){ hello(); }
산출:
$ cargo run --example hello
Compiling customderive v0.1.1 (file:///tmp/cd)
Normalized source code: struct Qqq;
Syn's AST: DeriveInput { ident: Ident("Qqq"), vis: Inherited, attrs: [], generics: Generics { lifetimes: [], ty_params: [], where_clause: WhereClause { predicates: [] } }, body: Struct(Unit) }
Quoted code: Tokens("fn hello ( ) { println ! ( \"Hello, {}!\" , stringify ! ( Qqq ) ) ; }")
warning: struct is never used: <snip>
Finished dev [unoptimized + debuginfo] target(s) in 3.79 secs
Running `target/x86_64-unknown-linux-gnu/debug/examples/hello`
Hello, Qqq!
최소 더미 커스텀 파생
Cargo.toml :
[package] name = "customderive" version = "0.1.0" [lib] proc-macro=true
src / lib.rs :
#![crate_type = "proc-macro"] extern crate proc_macro; use proc_macro::TokenStream; #[proc_macro_derive(Dummy)] pub fn qqq(input: TokenStream) -> TokenStream { "".parse().unwrap() }
examples / hello.rs
#[macro_use] extern crate customderive; #[derive(Dummy)] struct Qqq; fn main(){}
게터와 세터
Cargo.toml :
[package] name = "gettersetter" version = "0.1.0" [lib] proc-macro=true [dependencies] quote="^0.3.12" syn="^0.11.4"
src / lib.rs :
#![crate_type = "proc-macro"] extern crate proc_macro; use proc_macro::TokenStream; extern crate syn; #[macro_use] extern crate quote; #[proc_macro_derive(GetSet)] pub fn qqq(input: TokenStream) -> TokenStream { let source = input.to_string(); let ast = syn::parse_derive_input(&source).unwrap(); let struct_name = &ast.ident; if let syn::Body::Struct(s) = ast.body { let field_names : Vec<_> = s.fields().iter().map(|ref x| x.ident.clone().unwrap()).collect(); let field_getter_names = field_names.iter().map(|ref x| syn::Ident::new(format!("get_{}", x).as_str())); let field_setter_names = field_names.iter().map(|ref x| syn::Ident::new(format!("set_{}", x).as_str())); let field_types : Vec<_> = s.fields().iter().map(|ref x| x.ty.clone()).collect(); let field_names2 = field_names.clone(); let field_names3 = field_names.clone(); let field_types2 = field_types.clone(); let quoted_code = quote!{ #[allow(dead_code)] impl #struct_name { #( fn #field_getter_names(&self) -> &#field_types { &self.#field_names2 } fn #field_setter_names(&mut self, x : #field_types2) { self.#field_names3 = x; } )* } }; return quoted_code.parse().unwrap(); } // not a struct "".parse().unwrap() }
examples / hello.rs :
#[macro_use] extern crate gettersetter; #[derive(GetSet)] struct Qqq { x : i32, y : String, } fn main(){ let mut a = Qqq { x: 3, y: "zzaaqq".to_string() }; println!("{}", a.get_x()); a.set_y("123213".to_string()); println!("{}", a.get_y()); }
참조 : https://github.com/emk/accessors
Modified text is an extract of the original Stack Overflow Documentation
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