async-stream-impl-0.3.4/.cargo_vcs_info.json0000644000000001570000000000100144100ustar { "git": { "sha1": "bf41b9645fe39b8865da2f25edc286eb42d49ec8" }, "path_in_vcs": "async-stream-impl" }async-stream-impl-0.3.4/Cargo.toml0000644000000020550000000000100124050ustar # THIS FILE IS AUTOMATICALLY GENERATED BY CARGO # # When uploading crates to the registry Cargo will automatically # "normalize" Cargo.toml files for maximal compatibility # with all versions of Cargo and also rewrite `path` dependencies # to registry (e.g., crates.io) dependencies. # # If you are reading this file be aware that the original Cargo.toml # will likely look very different (and much more reasonable). # See Cargo.toml.orig for the original contents. [package] edition = "2018" rust-version = "1.45" name = "async-stream-impl" version = "0.3.4" authors = ["Carl Lerche "] description = "proc macros for async-stream crate" license = "MIT" repository = "https://github.com/tokio-rs/async-stream" [lib] proc-macro = true [dependencies.proc-macro2] version = "1" [dependencies.quote] version = "1" [dependencies.syn] version = "1" features = [ "full", "visit-mut", ] [dev-dependencies.futures-core] version = "0.3" [dev-dependencies.futures-util] version = "0.3" [dev-dependencies.tokio] version = "1" features = ["full"] async-stream-impl-0.3.4/Cargo.toml.orig000064400000000000000000000010411046102023000160600ustar 00000000000000[package] name = "async-stream-impl" version = "0.3.4" edition = "2018" rust-version = "1.45" license = "MIT" authors = ["Carl Lerche "] description = "proc macros for async-stream crate" repository = "https://github.com/tokio-rs/async-stream" [lib] proc-macro = true [dependencies] proc-macro2 = "1" syn = { version = "1", features = ["full", "visit-mut"] } quote = "1" [dev-dependencies] async-stream = { path = "../async-stream" } futures-core = "0.3" futures-util = "0.3" tokio = { version = "1", features = ["full"] } async-stream-impl-0.3.4/LICENSE000064400000000000000000000041001046102023000141750ustar 00000000000000Copyright (c) 2019 Carl Lerche Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Copyright (c) 2018 David Tolnay Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. async-stream-impl-0.3.4/src/lib.rs000064400000000000000000000232431046102023000151040ustar 00000000000000use proc_macro::TokenStream; use proc_macro2::{Group, TokenStream as TokenStream2, TokenTree}; use quote::quote; use syn::parse::{Parse, ParseStream, Parser, Result}; use syn::visit_mut::VisitMut; struct Scrub<'a> { /// Whether the stream is a try stream. is_try: bool, /// The unit expression, `()`. unit: Box, has_yielded: bool, crate_path: &'a TokenStream2, } fn parse_input(input: TokenStream) -> syn::Result<(TokenStream2, Vec)> { let mut input = TokenStream2::from(input).into_iter(); let crate_path = match input.next().unwrap() { TokenTree::Group(group) => group.stream(), _ => panic!(), }; let stmts = syn::Block::parse_within.parse2(replace_for_await(input))?; Ok((crate_path, stmts)) } impl<'a> Scrub<'a> { fn new(is_try: bool, crate_path: &'a TokenStream2) -> Self { Self { is_try, unit: syn::parse_quote!(()), has_yielded: false, crate_path, } } } struct Partial(T, TokenStream2); impl Parse for Partial { fn parse(input: ParseStream) -> Result { Ok(Partial(input.parse()?, input.parse()?)) } } fn visit_token_stream_impl( visitor: &mut Scrub<'_>, tokens: TokenStream2, modified: &mut bool, out: &mut TokenStream2, ) { use quote::ToTokens; use quote::TokenStreamExt; let mut tokens = tokens.into_iter().peekable(); while let Some(tt) = tokens.next() { match tt { TokenTree::Ident(i) if i == "yield" => { let stream = std::iter::once(TokenTree::Ident(i)).chain(tokens).collect(); match syn::parse2(stream) { Ok(Partial(yield_expr, rest)) => { let mut expr = syn::Expr::Yield(yield_expr); visitor.visit_expr_mut(&mut expr); expr.to_tokens(out); *modified = true; tokens = rest.into_iter().peekable(); } Err(e) => { out.append_all(&mut e.to_compile_error().into_iter()); *modified = true; return; } } } TokenTree::Ident(i) if i == "stream" || i == "try_stream" => { out.append(TokenTree::Ident(i)); match tokens.peek() { Some(TokenTree::Punct(p)) if p.as_char() == '!' => { out.extend(tokens.next()); // ! if let Some(TokenTree::Group(_)) = tokens.peek() { out.extend(tokens.next()); // { .. } or [ .. ] or ( .. ) } } _ => {} } } TokenTree::Group(group) => { let mut content = group.stream(); *modified |= visitor.visit_token_stream(&mut content); let mut new = Group::new(group.delimiter(), content); new.set_span(group.span()); out.append(new); } other => out.append(other), } } } impl Scrub<'_> { fn visit_token_stream(&mut self, tokens: &mut TokenStream2) -> bool { let (mut out, mut modified) = (TokenStream2::new(), false); visit_token_stream_impl(self, tokens.clone(), &mut modified, &mut out); if modified { *tokens = out; } modified } } impl VisitMut for Scrub<'_> { fn visit_expr_mut(&mut self, i: &mut syn::Expr) { match i { syn::Expr::Yield(yield_expr) => { self.has_yielded = true; syn::visit_mut::visit_expr_yield_mut(self, yield_expr); let value_expr = yield_expr.expr.as_ref().unwrap_or(&self.unit); // let ident = &self.yielder; *i = if self.is_try { syn::parse_quote! { __yield_tx.send(::core::result::Result::Ok(#value_expr)).await } } else { syn::parse_quote! { __yield_tx.send(#value_expr).await } }; } syn::Expr::Try(try_expr) => { syn::visit_mut::visit_expr_try_mut(self, try_expr); // let ident = &self.yielder; let e = &try_expr.expr; *i = syn::parse_quote! { match #e { ::core::result::Result::Ok(v) => v, ::core::result::Result::Err(e) => { __yield_tx.send(::core::result::Result::Err(e.into())).await; return; } } }; } syn::Expr::Closure(_) | syn::Expr::Async(_) => { // Don't transform inner closures or async blocks. } syn::Expr::ForLoop(expr) => { syn::visit_mut::visit_expr_for_loop_mut(self, expr); // TODO: Should we allow other attributes? if expr.attrs.len() != 1 || !expr.attrs[0].path.is_ident("await") { return; } let syn::ExprForLoop { attrs, label, pat, expr, body, .. } = expr; let attr = attrs.pop().unwrap(); if let Err(e) = syn::parse2::(attr.tokens) { *i = syn::parse2(e.to_compile_error()).unwrap(); return; } let crate_path = self.crate_path; *i = syn::parse_quote! {{ let mut __pinned = #expr; let mut __pinned = unsafe { ::core::pin::Pin::new_unchecked(&mut __pinned) }; #label loop { let #pat = match #crate_path::__private::next(&mut __pinned).await { ::core::option::Option::Some(e) => e, ::core::option::Option::None => break, }; #body } }} } _ => syn::visit_mut::visit_expr_mut(self, i), } } fn visit_macro_mut(&mut self, mac: &mut syn::Macro) { let mac_ident = mac.path.segments.last().map(|p| &p.ident); if mac_ident.map_or(false, |i| i == "stream" || i == "try_stream") { return; } self.visit_token_stream(&mut mac.tokens); } fn visit_item_mut(&mut self, i: &mut syn::Item) { // Recurse into macros but otherwise don't transform inner items. if let syn::Item::Macro(i) = i { self.visit_macro_mut(&mut i.mac); } } } /// The first token tree in the stream must be a group containing the path to the `async-stream` /// crate. #[proc_macro] #[doc(hidden)] pub fn stream_inner(input: TokenStream) -> TokenStream { let (crate_path, mut stmts) = match parse_input(input) { Ok(x) => x, Err(e) => return e.to_compile_error().into(), }; let mut scrub = Scrub::new(false, &crate_path); for stmt in &mut stmts { scrub.visit_stmt_mut(stmt); } let dummy_yield = if scrub.has_yielded { None } else { Some(quote!(if false { __yield_tx.send(()).await; })) }; quote!({ let (mut __yield_tx, __yield_rx) = unsafe { #crate_path::__private::yielder::pair() }; #crate_path::__private::AsyncStream::new(__yield_rx, async move { #dummy_yield #(#stmts)* }) }) .into() } /// The first token tree in the stream must be a group containing the path to the `async-stream` /// crate. #[proc_macro] #[doc(hidden)] pub fn try_stream_inner(input: TokenStream) -> TokenStream { let (crate_path, mut stmts) = match parse_input(input) { Ok(x) => x, Err(e) => return e.to_compile_error().into(), }; let mut scrub = Scrub::new(true, &crate_path); for stmt in &mut stmts { scrub.visit_stmt_mut(stmt); } let dummy_yield = if scrub.has_yielded { None } else { Some(quote!(if false { __yield_tx.send(()).await; })) }; quote!({ let (mut __yield_tx, __yield_rx) = unsafe { #crate_path::__private::yielder::pair() }; #crate_path::__private::AsyncStream::new(__yield_rx, async move { #dummy_yield #(#stmts)* }) }) .into() } /// Replace `for await` with `#[await] for`, which will be later transformed into a `next` loop. fn replace_for_await(input: impl IntoIterator) -> TokenStream2 { let mut input = input.into_iter().peekable(); let mut tokens = Vec::new(); while let Some(token) = input.next() { match token { TokenTree::Ident(ident) => { match input.peek() { Some(TokenTree::Ident(next)) if ident == "for" && next == "await" => { tokens.extend(quote!(#[#next])); let _ = input.next(); } _ => {} } tokens.push(ident.into()); } TokenTree::Group(group) => { let stream = replace_for_await(group.stream()); let mut new_group = Group::new(group.delimiter(), stream); new_group.set_span(group.span()); tokens.push(new_group.into()); } _ => tokens.push(token), } } tokens.into_iter().collect() }