summaryrefslogtreecommitdiffstats
path: root/vendor/syn/src/custom_punctuation.rs
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /vendor/syn/src/custom_punctuation.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/syn/src/custom_punctuation.rs')
-rw-r--r--vendor/syn/src/custom_punctuation.rs300
1 files changed, 300 insertions, 0 deletions
diff --git a/vendor/syn/src/custom_punctuation.rs b/vendor/syn/src/custom_punctuation.rs
new file mode 100644
index 000000000..118a8453d
--- /dev/null
+++ b/vendor/syn/src/custom_punctuation.rs
@@ -0,0 +1,300 @@
+/// 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]: crate::parse::ParseBuffer::peek
+/// [Parsing]: crate::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]
+macro_rules! custom_punctuation {
+ ($ident:ident, $($tt:tt)+) => {
+ pub struct $ident {
+ pub spans: $crate::custom_punctuation_repr!($($tt)+),
+ }
+
+ #[doc(hidden)]
+ #[allow(dead_code, non_snake_case)]
+ pub fn $ident<__S: $crate::__private::IntoSpans<$crate::custom_punctuation_repr!($($tt)+)>>(
+ spans: __S,
+ ) -> $ident {
+ let _validate_len = 0 $(+ $crate::custom_punctuation_len!(strict, $tt))*;
+ $ident {
+ spans: $crate::__private::IntoSpans::into_spans(spans)
+ }
+ }
+
+ impl $crate::__private::Default for $ident {
+ fn default() -> Self {
+ $ident($crate::__private::Span::call_site())
+ }
+ }
+
+ $crate::impl_parse_for_custom_punctuation!($ident, $($tt)+);
+ $crate::impl_to_tokens_for_custom_punctuation!($ident, $($tt)+);
+ $crate::impl_clone_for_custom_punctuation!($ident, $($tt)+);
+ $crate::impl_extra_traits_for_custom_punctuation!($ident, $($tt)+);
+ };
+}
+
+// Not public API.
+#[cfg(feature = "parsing")]
+#[doc(hidden)]
+#[macro_export]
+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, $crate::stringify_punct!($($tt)+))
+ }
+
+ fn display() -> &'static $crate::__private::str {
+ concat!("`", $crate::stringify_punct!($($tt)+), "`")
+ }
+ }
+
+ impl $crate::parse::Parse for $ident {
+ fn parse(input: $crate::parse::ParseStream) -> $crate::parse::Result<$ident> {
+ let spans: $crate::custom_punctuation_repr!($($tt)+) =
+ $crate::token::parsing::punct(input, $crate::stringify_punct!($($tt)+))?;
+ Ok($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]
+macro_rules! impl_to_tokens_for_custom_punctuation {
+ ($ident:ident, $($tt:tt)+) => {
+ impl $crate::__private::ToTokens for $ident {
+ fn to_tokens(&self, tokens: &mut $crate::__private::TokenStream2) {
+ $crate::token::printing::punct($crate::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::__private::Copy for $ident {}
+
+ #[allow(clippy::expl_impl_clone_on_copy)]
+ impl $crate::__private::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::__private::Debug for $ident {
+ fn fmt(&self, f: &mut $crate::__private::Formatter) -> $crate::__private::fmt::Result {
+ $crate::__private::Formatter::write_str(f, stringify!($ident))
+ }
+ }
+
+ impl $crate::__private::Eq for $ident {}
+
+ impl $crate::__private::PartialEq for $ident {
+ fn eq(&self, _other: &Self) -> $crate::__private::bool {
+ true
+ }
+ }
+
+ impl $crate::__private::Hash for $ident {
+ fn hash<__H: $crate::__private::Hasher>(&self, _state: &mut __H) {}
+ }
+ };
+}
+
+// Not public API.
+#[cfg(not(feature = "extra-traits"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_extra_traits_for_custom_punctuation {
+ ($ident:ident, $($tt:tt)+) => {};
+}
+
+// Not public API.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! custom_punctuation_repr {
+ ($($tt:tt)+) => {
+ [$crate::__private::Span; 0 $(+ $crate::custom_punctuation_len!(lenient, $tt))+]
+ };
+}
+
+// Not public API.
+#[doc(hidden)]
+#[macro_export]
+#[rustfmt::skip]
+macro_rules! custom_punctuation_len {
+ ($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) => {{ $crate::custom_punctuation_unexpected!($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)),+)
+ };
+}