Crate typed_quote 

typed-quote

A fully typed quote!() alternative for both proc-macro and proc-macro2.

Quick start

Output TokenStream

typed_quote::quote!(...) returns a fully typed value that implements IntoTokens, ToTokens, WithSpan, IntoTokenTree or ToTokenTree depending on the quoted content.

• Call ts.into_token_stream() to get proc_macro::TokenStream.
• Call ts.into_token_stream2() to get proc_macro2::TokenStream.

use typed_quote::prelude::*;

let crate_name = quote!("typed-quote");
let tokens = quote!(hello #crate_name !);

let ts: proc_macro2::TokenStream = tokens.into_token_stream2();

assert_eq!(ts.to_string(), r#"hello "typed-quote" !"#);

Set span

• Call ts.with_default_span(span) to specify a span only for un-spanned tokens in ts.

  • quote!(un-spanned).with_default_span(span) will specify span for all tokens.
  • quote!(#quoted_var).with_default_span(span) will call quoted_var.with_default_span(span).
  • proc_macro::TokenStream::from_str("...").unwrap().with_default_span(span) will not change span because proc_macro::TokenStream already has a span.

• Call ts.with_replaced_span(span) to set span for all tokens in ts.

  • Note that, if the ident of proc_macro::Ident and proc_macro2::Ident is exactly $crate, then its span will not be replaced.

Comparison with ::quote

typed_quote::typed_quote!() is an alias of typed_quote::quote!() so you can disambiguate typed_quote!() from quote::quote!().

• typed_quote is new, not well tested, and will contain breaking changes in the future. You should use ::quote for production.

• ::quote::quote!() returns a proc_macro2::TokenStream.

  typed_quote!() returns a fully typed struct that implements IntoTokens and you can decide to output proc_macro::TokenStream or proc_macro2::TokenStream.

• ::quote has quote_spanned!(span => ...).

  But in typed_quote, use typed_quote!(...).with_default_span(span) instead.

• ::quote::quote!(#var) only references &var but typed_quote!(#var) moves var. Since &impl ToTokens implements both IntoToken and Copy, let var = &var; typed_quote!(#var) will work if var is a value of impl ToTokens.

• ::quote::ToTokens is dyn-

cargo features

• alloc (default)

  This feature implements traits for Box, Rc.

  This library is no_std and only alloc is enabled by default.

• proc-macro and proc-macro2

  Enable one or both of these features if necessary:

  cargo add typed-quote --features proc-macro
  cargo add typed-quote --features proc-macro2
  cargo add typed-quote --features proc-macro,proc-macro2

  You don’t need to enable them when you’re writing a library that just inputs/outputs tokens. Users of your library can decide which feature to enable and call the corresponding into_token_stream or into_token_stream2.

  cargo add typed-quote

  use typed_quote::prelude::*;
  
  fn braced(stream: impl IntoTokens) -> impl IntoTokenTree {
      quote!({ stream })
  }

Cheat sheet

Type	derived Traits	value examples
Never	Into/ToTokenTree Into/ToTokens (Ref)WithSpan
Either<A, B>	Into/ToTokenTree Into/ToTokens (Ref)WithSpan	if condition { Either::A(quote!(a)) } else { Either::B(quote!(b)) }
Option<T>	Into/ToTokens (Ref)WithSpan	if condition { Some(quote!(some)) } else { None }
&T	Into/ToTokens where T: ToTokens (Ref)WithSpan where T: RefWithSpan	&quote!(ref)
Box<T: ?Sized>	Into/ToTokenTree Into/ToTokens	Box::new(quote!(_)) Box::new(quote!(_)) as Box<dyn ToTokenTree>
Rc<T: ?Sized>	Into/ToTokenTree where T: ToTokenTree Into/ToTokens where T: ToTokens	Rc::new(quote!(_)) Rc::new(quote!(_)) as Rc<dyn ToTokenTree>
Empty	Into/ToTokens (Ref)WithSpan	quote!()
grouped token stream: {...} [...] (...)	Into/ToTokens (Ref)WithSpan	quote!( { braced tokens } ) quote!( [ 0, 1, 2, 3, 4 ] ) quote!( ( #tokens ) )
ConstIdent<T: ?Sized + HasConstIdent> Ident<'_>	Into/ToTokenTree Into/ToTokens (Ref)WithSpan	quote!(my_ident) quote!(my_ident).as_ident()
ConstLifetime<T: ?Sized + HasConstLifetime> Lifetime<'_>	Into/ToTokens (Ref)WithSpan	quote!('my_lifetime) quote!('my_lifetime).as_lifetime()
ConstLiteral<T: ?Sized + HasConstLiteral> Literal<'_>	Into/ToTokenTree Into/ToTokens (Ref)WithSpan	quote!("my literal") quote!("my literal").as_literal()
Concat<A, B>	Into/ToTokens (Ref)WithSpan	let a = quote!(a); let b = quote!(b); quote!(#a #b)
IterTokens<I: IntoIterator>	IntoTokens where I::Item: IntoTokens ToTokens where I::Item: IntoTokens, I: Clone WithSpan where I::Item: WithSpan RefWithSpan where I::Item: WithSpan, I: Clone	IterTokens([quote!(a); 10])
punctuation	Into/ToTokenTree Into/ToTokens (Ref)WithSpan	quote!( : ) quote!( . ) quote!( * )
punctuations	Into/ToTokens (Ref)WithSpan	quote!( :: ) quote!( .. ) quote!( *= )
proc_macro(2)::{   TokenTree(2),   Group(2),   Ident(2),   Punct(2),   Literal(2), }	Into/ToTokenTree Into/ToTokens (Ref)WithSpan	proc_macro::Ident::new( "tt", proc_macro::Span::call_site() )
proc_macro(2)::TokenStream(2)	Into/ToTokens (Ref)WithSpan	proc_macro::TokenStream::new()

Re-exports

pub use quote as typed_quote;

Modules

maybe_span

prelude

tokens

Macros

quote

quote_token

Enums

Either

Never

Traits

IntoTokenTree

Into a token tree.

IntoTokens

Into token stream.

RefWithSpan

To tokens with new span.

Span

A proc_macro::Span or proc_macro2::Span.

ToTokenTree

To a token tree.

ToTokens

To token stream.

WithSpan

Into tokens with new span.