Proc macros -- getting the contents of a function

[govardhangdg]

Hello! I want to write a macro that acts on a function and produces a new function that performs the same operations as the original function twice.
I am trying to write an attribute macro. As I thought it was better suited for the task.

#[double]
fn print_hello() {
    println!("hello");
}

I want this to produce a new function print_hello_double (for example)

fn print_hello_double() {
    println!("hello");
    println!("hello");
}

I am using syn and quote crates. I am able to get the parsed version of the original function's contents using the syn crate. syn::Block.
But I am not able to understand how to use this to get the contents inside the new function produced (using quote! macro)

I tried to just include the parsed statements inside the quote! macro

quote! {
    // ....
    #stmts // stmts is the syn::Block instance obtained   
   // ....
}

But I get the error saying that this doesn't implement the ToTokens trait from quote crate.

the trait bound std::vec::Vec<syn::stmt::Stmt>: quote::to_tokens::ToTokens is not satisfied
required by `quote::to_tokens::ToTokens::to_tokens

[Cerber-Ursi]

Due to the error, I presume that stmts is not syn::Block, but the vector of syn::Stmt extracted from the block. For this case, quote has the separate syntax:

quote! {
    // ....
    #(#stmts)*
   // ....
}

[govardhangdg]

Oh thanks! I failed to notice that it was a vector (mainly because I am trying to debug by using println! within the macro and my function had only one statement). This solved my problem. Thanks, once again