diff options
Diffstat (limited to 'syn/src/custom_punctuation.rs')
| -rw-r--r-- | syn/src/custom_punctuation.rs | 309 |
1 files changed, 0 insertions, 309 deletions
diff --git a/syn/src/custom_punctuation.rs b/syn/src/custom_punctuation.rs deleted file mode 100644 index 29fa448..0000000 --- a/syn/src/custom_punctuation.rs +++ /dev/null @@ -1,309 +0,0 @@ -/// Define a type that supports parsing and printing a multi-character symbol -/// as if it were a punctuation token. -/// -/// # Usage -/// -/// ``` -/// syn::custom_punctuation!(LeftRightArrow, <=>); -/// ``` -/// -/// The generated syntax tree node supports the following operations just like -/// any built-in punctuation token. -/// -/// - [Peeking] — `input.peek(LeftRightArrow)` -/// -/// - [Parsing] — `input.parse::<LeftRightArrow>()?` -/// -/// - [Printing] — `quote!( ... #lrarrow ... )` -/// -/// - Construction from a [`Span`] — `let lrarrow = LeftRightArrow(sp)` -/// -/// - Construction from multiple [`Span`] — `let lrarrow = LeftRightArrow([sp, sp, sp])` -/// -/// - Field access to its spans — `let spans = lrarrow.spans` -/// -/// [Peeking]: parse::ParseBuffer::peek -/// [Parsing]: parse::ParseBuffer::parse -/// [Printing]: quote::ToTokens -/// [`Span`]: proc_macro2::Span -/// -/// # Example -/// -/// ``` -/// use proc_macro2::{TokenStream, TokenTree}; -/// use syn::parse::{Parse, ParseStream, Peek, Result}; -/// use syn::punctuated::Punctuated; -/// use syn::Expr; -/// -/// syn::custom_punctuation!(PathSeparator, </>); -/// -/// // expr </> expr </> expr ... -/// struct PathSegments { -/// segments: Punctuated<Expr, PathSeparator>, -/// } -/// -/// impl Parse for PathSegments { -/// fn parse(input: ParseStream) -> Result<Self> { -/// let mut segments = Punctuated::new(); -/// -/// let first = parse_until(input, PathSeparator)?; -/// segments.push_value(syn::parse2(first)?); -/// -/// while input.peek(PathSeparator) { -/// segments.push_punct(input.parse()?); -/// -/// let next = parse_until(input, PathSeparator)?; -/// segments.push_value(syn::parse2(next)?); -/// } -/// -/// Ok(PathSegments { segments }) -/// } -/// } -/// -/// fn parse_until<E: Peek>(input: ParseStream, end: E) -> Result<TokenStream> { -/// let mut tokens = TokenStream::new(); -/// while !input.is_empty() && !input.peek(end) { -/// let next: TokenTree = input.parse()?; -/// tokens.extend(Some(next)); -/// } -/// Ok(tokens) -/// } -/// -/// fn main() { -/// let input = r#" a::b </> c::d::e "#; -/// let _: PathSegments = syn::parse_str(input).unwrap(); -/// } -/// ``` -#[macro_export(local_inner_macros)] -macro_rules! custom_punctuation { - ($ident:ident, $($tt:tt)+) => { - pub struct $ident { - pub spans: custom_punctuation_repr!($($tt)+), - } - - #[doc(hidden)] - #[allow(non_snake_case)] - pub fn $ident<__S: $crate::export::IntoSpans<custom_punctuation_repr!($($tt)+)>>( - spans: __S, - ) -> $ident { - let _validate_len = 0 $(+ custom_punctuation_len!(strict, $tt))*; - $ident { - spans: $crate::export::IntoSpans::into_spans(spans) - } - } - - impl $crate::export::Default for $ident { - fn default() -> Self { - $ident($crate::export::Span::call_site()) - } - } - - impl_parse_for_custom_punctuation!($ident, $($tt)+); - impl_to_tokens_for_custom_punctuation!($ident, $($tt)+); - impl_clone_for_custom_punctuation!($ident, $($tt)+); - impl_extra_traits_for_custom_punctuation!($ident, $($tt)+); - }; -} - -// Not public API. -#[cfg(feature = "parsing")] -#[doc(hidden)] -#[macro_export(local_inner_macros)] -macro_rules! impl_parse_for_custom_punctuation { - ($ident:ident, $($tt:tt)+) => { - impl $crate::token::CustomToken for $ident { - fn peek(cursor: $crate::buffer::Cursor) -> bool { - $crate::token::parsing::peek_punct(cursor, stringify_punct!($($tt)+)) - } - - fn display() -> &'static $crate::export::str { - custom_punctuation_concat!("`", stringify_punct!($($tt)+), "`") - } - } - - impl $crate::parse::Parse for $ident { - fn parse(input: $crate::parse::ParseStream) -> $crate::parse::Result<$ident> { - let spans: custom_punctuation_repr!($($tt)+) = - $crate::token::parsing::punct(input, stringify_punct!($($tt)+))?; - Ok($ident(spans)) - } - } - }; -} - -// Not public API. -#[cfg(not(feature = "parsing"))] -#[doc(hidden)] -#[macro_export] -macro_rules! impl_parse_for_custom_punctuation { - ($ident:ident, $($tt:tt)+) => {}; -} - -// Not public API. -#[cfg(feature = "printing")] -#[doc(hidden)] -#[macro_export(local_inner_macros)] -macro_rules! impl_to_tokens_for_custom_punctuation { - ($ident:ident, $($tt:tt)+) => { - impl $crate::export::ToTokens for $ident { - fn to_tokens(&self, tokens: &mut $crate::export::TokenStream2) { - $crate::token::printing::punct(stringify_punct!($($tt)+), &self.spans, tokens) - } - } - }; -} - -// Not public API. -#[cfg(not(feature = "printing"))] -#[doc(hidden)] -#[macro_export] -macro_rules! impl_to_tokens_for_custom_punctuation { - ($ident:ident, $($tt:tt)+) => {}; -} - -// Not public API. -#[cfg(feature = "clone-impls")] -#[doc(hidden)] -#[macro_export] -macro_rules! impl_clone_for_custom_punctuation { - ($ident:ident, $($tt:tt)+) => { - impl $crate::export::Copy for $ident {} - - impl $crate::export::Clone for $ident { - fn clone(&self) -> Self { - *self - } - } - }; -} - -// Not public API. -#[cfg(not(feature = "clone-impls"))] -#[doc(hidden)] -#[macro_export] -macro_rules! impl_clone_for_custom_punctuation { - ($ident:ident, $($tt:tt)+) => {}; -} - -// Not public API. -#[cfg(feature = "extra-traits")] -#[doc(hidden)] -#[macro_export] -macro_rules! impl_extra_traits_for_custom_punctuation { - ($ident:ident, $($tt:tt)+) => { - impl $crate::export::Debug for $ident { - fn fmt(&self, f: &mut $crate::export::Formatter) -> $crate::export::fmt::Result { - $crate::export::Formatter::write_str(f, stringify!($ident)) - } - } - - impl $crate::export::Eq for $ident {} - - impl $crate::export::PartialEq for $ident { - fn eq(&self, _other: &Self) -> $crate::export::bool { - true - } - } - - impl $crate::export::Hash for $ident { - fn hash<__H: $crate::export::Hasher>(&self, _state: &mut __H) {} - } - }; -} - -// Not public API. -#[cfg(not(feature = "extra-traits"))] -#[doc(hidden)] -#[macro_export] -macro_rules! impl_extra_traits_for_custom_punctuation { - ($ident:ident, $($tt:tt)+) => {}; -} - -// Not public API. -#[doc(hidden)] -#[macro_export(local_inner_macros)] -macro_rules! custom_punctuation_repr { - ($($tt:tt)+) => { - [$crate::export::Span; 0 $(+ custom_punctuation_len!(lenient, $tt))+] - }; -} - -// Not public API. -#[doc(hidden)] -#[macro_export(local_inner_macros)] -#[rustfmt::skip] -macro_rules! custom_punctuation_len { - ($mode:ident, +) => { 1 }; - ($mode:ident, +=) => { 2 }; - ($mode:ident, &) => { 1 }; - ($mode:ident, &&) => { 2 }; - ($mode:ident, &=) => { 2 }; - ($mode:ident, @) => { 1 }; - ($mode:ident, !) => { 1 }; - ($mode:ident, ^) => { 1 }; - ($mode:ident, ^=) => { 2 }; - ($mode:ident, :) => { 1 }; - ($mode:ident, ::) => { 2 }; - ($mode:ident, ,) => { 1 }; - ($mode:ident, /) => { 1 }; - ($mode:ident, /=) => { 2 }; - ($mode:ident, .) => { 1 }; - ($mode:ident, ..) => { 2 }; - ($mode:ident, ...) => { 3 }; - ($mode:ident, ..=) => { 3 }; - ($mode:ident, =) => { 1 }; - ($mode:ident, ==) => { 2 }; - ($mode:ident, >=) => { 2 }; - ($mode:ident, >) => { 1 }; - ($mode:ident, <=) => { 2 }; - ($mode:ident, <) => { 1 }; - ($mode:ident, *=) => { 2 }; - ($mode:ident, !=) => { 2 }; - ($mode:ident, |) => { 1 }; - ($mode:ident, |=) => { 2 }; - ($mode:ident, ||) => { 2 }; - ($mode:ident, #) => { 1 }; - ($mode:ident, ?) => { 1 }; - ($mode:ident, ->) => { 2 }; - ($mode:ident, <-) => { 2 }; - ($mode:ident, %) => { 1 }; - ($mode:ident, %=) => { 2 }; - ($mode:ident, =>) => { 2 }; - ($mode:ident, ;) => { 1 }; - ($mode:ident, <<) => { 2 }; - ($mode:ident, <<=) => { 3 }; - ($mode:ident, >>) => { 2 }; - ($mode:ident, >>=) => { 3 }; - ($mode:ident, *) => { 1 }; - ($mode:ident, -) => { 1 }; - ($mode:ident, -=) => { 2 }; - ($mode:ident, ~) => { 1 }; - (lenient, $tt:tt) => { 0 }; - (strict, $tt:tt) => {{ custom_punctuation_unexpected!($tt); 0 }}; -} - -// Not public API. -#[doc(hidden)] -#[macro_export] -macro_rules! custom_punctuation_unexpected { - () => {}; -} - -// Not public API. -#[doc(hidden)] -#[macro_export] -macro_rules! stringify_punct { - ($($tt:tt)+) => { - concat!($(stringify!($tt)),+) - }; -} - -// Not public API. -// Without this, local_inner_macros breaks when looking for concat! -#[doc(hidden)] -#[macro_export] -macro_rules! custom_punctuation_concat { - ($($tt:tt)*) => { - concat!($($tt)*) - }; -} |