use proc_macro2::TokenStream;
use quote::{ToTokens, quote};
use syn::{
Expr, ExprClosure, Result,
parse::{Parse, ParseStream},
token::Comma,
};
pub struct Task {
result: TokenStream,
}
impl Parse for Task {
fn parse(input: ParseStream) -> Result<Self> {
let result = match input.parse::<ExprClosure>() {
Ok(closure) => {
let inputs = closure.inputs;
let body = closure.body;
quote! {
|#inputs|{
Box::pin(#body)
}
}
}
Err(_) => input.cursor().token_stream(),
};
while !input.is_empty() {
input.step(|cursor| {
let mut rest = *cursor;
while let Some((_, next)) = rest.token_tree() {
rest = next
}
Ok(((), rest))
})?;
}
Ok(Self { result })
}
}
impl ToTokens for Task {
fn to_tokens(&self, tokens: &mut TokenStream) {
self.result.to_tokens(tokens);
}
}
pub struct SetTask {
result: TokenStream,
}
impl Parse for SetTask {
fn parse(input: ParseStream) -> Result<Self> {
let source = input.parse::<Expr>()?;
input.parse::<Comma>()?;
let task = Task::parse(input)?;
let result = quote! {
#source.set_task_fn(#task)
};
Ok(Self { result })
}
}
impl ToTokens for SetTask {
fn to_tokens(&self, tokens: &mut TokenStream) {
self.result.to_tokens(tokens);
}
}