proc_macro上的自我

Question

我正在编写一个过程宏，它接受结构的字段并将它们发送到另一个方法：

pub fn my_helper_macro_builder(macro_data: &MacroTokens) -> TokenStream {
    // Retrieves the fields and tries to add self to take it's value
    let insert_values: Vec<TokenStream> = fields
        .iter()
        .map(|ident| ident.to_string())
        .collect::<Vec<String>>()
        .iter()
        .map(|column| quote! { self.#column })
        .collect();

    quote! {
        #vis async fn insert(&self) {
            <#ty as CrudOperations<#ty>>::__insert(
                #table_name,
                #column_names_pretty,
                &[
                    #(#insert_values),*
                ]
            ).await;
        }
    }
}

当我尝试使用应该在self方法上接收的#vis async fn insert(&self)时，我会收到以下错误：

expected one of `,`, `.`, `;`, `?`, `]`, or an operator, found `"id"

如果我试图将引用宏的签名中可用的&self.连接到quote! {}本身，则会收到以下编译器错误：

   |
8  |   pub fn generate_insert_tokens(macro_data: &MacroTokens) -> TokenStream {
   |          ---------------------- this function can't have a `self` parameter
...
48 | /     quote! {
49 | |         #vis async fn insert(&self) {
50 | |             <#ty as CrudOperations<#ty>>::__insert(
51 | |                 #table_name, 
                       #column_names_pretty, 
                       &[
                            #self.#(#insert_values),*
                        ] 
...  |
57 | |         }
58 | |     }
   | |_____^ `self` value is a keyword only available in methods with a `self` parameter
   |
   = note: this error originates in the macro `$crate::quote_token_with_context` 

Answer 1

正如@Shepmaster所指出的，问题是，我是在串列的名称，所以最后的代码如下所示：

pub fn my_helper_macro_builder(macro_data: &MacroTokens) -> TokenStream {
    // Retrieves the fields and tries to add self to take it's value
    let insert_values = fields.iter().map( |ident| {
        quote! { &self.#ident }
    });

    quote! {
        #vis async fn insert(&self) {
            <#ty as CrudOperations<#ty>>::__insert(
                #table_name,
                #column_names_pretty,
                &[
                    #(#insert_values),*
                ]
            ).await;
        }
    }
}