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-rw-r--r--vendor/syn/src/lifetime.rs156
1 files changed, 156 insertions, 0 deletions
diff --git a/vendor/syn/src/lifetime.rs b/vendor/syn/src/lifetime.rs
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+use proc_macro2::{Ident, Span};
+use std::cmp::Ordering;
+use std::fmt::{self, Display};
+use std::hash::{Hash, Hasher};
+
+#[cfg(feature = "parsing")]
+use crate::lookahead;
+
+/// A Rust lifetime: `'a`.
+///
+/// Lifetime names must conform to the following rules:
+///
+/// - Must start with an apostrophe.
+/// - Must not consist of just an apostrophe: `'`.
+/// - Character after the apostrophe must be `_` or a Unicode code point with
+/// the XID_Start property.
+/// - All following characters must be Unicode code points with the XID_Continue
+/// property.
+pub struct Lifetime {
+ pub apostrophe: Span,
+ pub ident: Ident,
+}
+
+impl Lifetime {
+ /// # Panics
+ ///
+ /// Panics if the lifetime does not conform to the bulleted rules above.
+ ///
+ /// # Invocation
+ ///
+ /// ```
+ /// # use proc_macro2::Span;
+ /// # use syn::Lifetime;
+ /// #
+ /// # fn f() -> Lifetime {
+ /// Lifetime::new("'a", Span::call_site())
+ /// # }
+ /// ```
+ pub fn new(symbol: &str, span: Span) -> Self {
+ if !symbol.starts_with('\'') {
+ panic!(
+ "lifetime name must start with apostrophe as in \"'a\", got {:?}",
+ symbol
+ );
+ }
+
+ if symbol == "'" {
+ panic!("lifetime name must not be empty");
+ }
+
+ if !crate::ident::xid_ok(&symbol[1..]) {
+ panic!("{:?} is not a valid lifetime name", symbol);
+ }
+
+ Lifetime {
+ apostrophe: span,
+ ident: Ident::new(&symbol[1..], span),
+ }
+ }
+
+ pub fn span(&self) -> Span {
+ self.apostrophe
+ .join(self.ident.span())
+ .unwrap_or(self.apostrophe)
+ }
+
+ pub fn set_span(&mut self, span: Span) {
+ self.apostrophe = span;
+ self.ident.set_span(span);
+ }
+}
+
+impl Display for Lifetime {
+ fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ "'".fmt(formatter)?;
+ self.ident.fmt(formatter)
+ }
+}
+
+impl Clone for Lifetime {
+ fn clone(&self) -> Self {
+ Lifetime {
+ apostrophe: self.apostrophe,
+ ident: self.ident.clone(),
+ }
+ }
+}
+
+impl PartialEq for Lifetime {
+ fn eq(&self, other: &Lifetime) -> bool {
+ self.ident.eq(&other.ident)
+ }
+}
+
+impl Eq for Lifetime {}
+
+impl PartialOrd for Lifetime {
+ fn partial_cmp(&self, other: &Lifetime) -> Option<Ordering> {
+ Some(self.cmp(other))
+ }
+}
+
+impl Ord for Lifetime {
+ fn cmp(&self, other: &Lifetime) -> Ordering {
+ self.ident.cmp(&other.ident)
+ }
+}
+
+impl Hash for Lifetime {
+ fn hash<H: Hasher>(&self, h: &mut H) {
+ self.ident.hash(h);
+ }
+}
+
+#[cfg(feature = "parsing")]
+pub_if_not_doc! {
+ #[doc(hidden)]
+ #[allow(non_snake_case)]
+ pub fn Lifetime(marker: lookahead::TokenMarker) -> Lifetime {
+ match marker {}
+ }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+ use super::*;
+ use crate::parse::{Parse, ParseStream, Result};
+
+ #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
+ impl Parse for Lifetime {
+ fn parse(input: ParseStream) -> Result<Self> {
+ input.step(|cursor| {
+ cursor
+ .lifetime()
+ .ok_or_else(|| cursor.error("expected lifetime"))
+ })
+ }
+ }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+ use super::*;
+ use proc_macro2::{Punct, Spacing, TokenStream};
+ use quote::{ToTokens, TokenStreamExt};
+
+ #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))]
+ impl ToTokens for Lifetime {
+ fn to_tokens(&self, tokens: &mut TokenStream) {
+ let mut apostrophe = Punct::new('\'', Spacing::Joint);
+ apostrophe.set_span(self.apostrophe);
+ tokens.append(apostrophe);
+ self.ident.to_tokens(tokens);
+ }
+ }
+}