diff options
Diffstat (limited to 'vendor/quote/src/to_tokens.rs')
| -rw-r--r-- | vendor/quote/src/to_tokens.rs | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/vendor/quote/src/to_tokens.rs b/vendor/quote/src/to_tokens.rs new file mode 100644 index 0000000..23b6ec2 --- /dev/null +++ b/vendor/quote/src/to_tokens.rs @@ -0,0 +1,209 @@ +use super::TokenStreamExt; +use alloc::borrow::Cow; +use alloc::rc::Rc; +use core::iter; +use proc_macro2::{Group, Ident, Literal, Punct, Span, TokenStream, TokenTree}; + +/// Types that can be interpolated inside a `quote!` invocation. +/// +/// [`quote!`]: macro.quote.html +pub trait ToTokens { + /// Write `self` to the given `TokenStream`. + /// + /// The token append methods provided by the [`TokenStreamExt`] extension + /// trait may be useful for implementing `ToTokens`. + /// + /// [`TokenStreamExt`]: trait.TokenStreamExt.html + /// + /// # Example + /// + /// Example implementation for a struct representing Rust paths like + /// `std::cmp::PartialEq`: + /// + /// ``` + /// use proc_macro2::{TokenTree, Spacing, Span, Punct, TokenStream}; + /// use quote::{TokenStreamExt, ToTokens}; + /// + /// pub struct Path { + /// pub global: bool, + /// pub segments: Vec<PathSegment>, + /// } + /// + /// impl ToTokens for Path { + /// fn to_tokens(&self, tokens: &mut TokenStream) { + /// for (i, segment) in self.segments.iter().enumerate() { + /// if i > 0 || self.global { + /// // Double colon `::` + /// tokens.append(Punct::new(':', Spacing::Joint)); + /// tokens.append(Punct::new(':', Spacing::Alone)); + /// } + /// segment.to_tokens(tokens); + /// } + /// } + /// } + /// # + /// # pub struct PathSegment; + /// # + /// # impl ToTokens for PathSegment { + /// # fn to_tokens(&self, tokens: &mut TokenStream) { + /// # unimplemented!() + /// # } + /// # } + /// ``` + fn to_tokens(&self, tokens: &mut TokenStream); + + /// Convert `self` directly into a `TokenStream` object. + /// + /// This method is implicitly implemented using `to_tokens`, and acts as a + /// convenience method for consumers of the `ToTokens` trait. + fn to_token_stream(&self) -> TokenStream { + let mut tokens = TokenStream::new(); + self.to_tokens(&mut tokens); + tokens + } + + /// Convert `self` directly into a `TokenStream` object. + /// + /// This method is implicitly implemented using `to_tokens`, and acts as a + /// convenience method for consumers of the `ToTokens` trait. + fn into_token_stream(self) -> TokenStream + where + Self: Sized, + { + self.to_token_stream() + } +} + +impl<'a, T: ?Sized + ToTokens> ToTokens for &'a T { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl<'a, T: ?Sized + ToTokens> ToTokens for &'a mut T { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl<'a, T: ?Sized + ToOwned + ToTokens> ToTokens for Cow<'a, T> { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl<T: ?Sized + ToTokens> ToTokens for Box<T> { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl<T: ?Sized + ToTokens> ToTokens for Rc<T> { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl<T: ToTokens> ToTokens for Option<T> { + fn to_tokens(&self, tokens: &mut TokenStream) { + if let Some(ref t) = *self { + t.to_tokens(tokens); + } + } +} + +impl ToTokens for str { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::string(self)); + } +} + +impl ToTokens for String { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.as_str().to_tokens(tokens); + } +} + +macro_rules! primitive { + ($($t:ident => $name:ident)*) => { + $( + impl ToTokens for $t { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::$name(*self)); + } + } + )* + }; +} + +primitive! { + i8 => i8_suffixed + i16 => i16_suffixed + i32 => i32_suffixed + i64 => i64_suffixed + i128 => i128_suffixed + isize => isize_suffixed + + u8 => u8_suffixed + u16 => u16_suffixed + u32 => u32_suffixed + u64 => u64_suffixed + u128 => u128_suffixed + usize => usize_suffixed + + f32 => f32_suffixed + f64 => f64_suffixed +} + +impl ToTokens for char { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::character(*self)); + } +} + +impl ToTokens for bool { + fn to_tokens(&self, tokens: &mut TokenStream) { + let word = if *self { "true" } else { "false" }; + tokens.append(Ident::new(word, Span::call_site())); + } +} + +impl ToTokens for Group { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(self.clone()); + } +} + +impl ToTokens for Ident { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(self.clone()); + } +} + +impl ToTokens for Punct { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(self.clone()); + } +} + +impl ToTokens for Literal { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(self.clone()); + } +} + +impl ToTokens for TokenTree { + fn to_tokens(&self, dst: &mut TokenStream) { + dst.append(self.clone()); + } +} + +impl ToTokens for TokenStream { + fn to_tokens(&self, dst: &mut TokenStream) { + dst.extend(iter::once(self.clone())); + } + + fn into_token_stream(self) -> TokenStream { + self + } +} |