diff options
Diffstat (limited to 'vendor/syn/src/ident.rs')
-rw-r--r-- | vendor/syn/src/ident.rs | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/vendor/syn/src/ident.rs b/vendor/syn/src/ident.rs new file mode 100644 index 0000000..d0f4ba0 --- /dev/null +++ b/vendor/syn/src/ident.rs @@ -0,0 +1,107 @@ +#[cfg(feature = "parsing")] +use crate::lookahead; + +pub use proc_macro2::Ident; + +#[cfg(feature = "parsing")] +pub_if_not_doc! { + #[doc(hidden)] + #[allow(non_snake_case)] + pub fn Ident(marker: lookahead::TokenMarker) -> Ident { + match marker {} + } +} + +macro_rules! ident_from_token { + ($token:ident) => { + impl From<Token![$token]> for Ident { + fn from(token: Token![$token]) -> Ident { + Ident::new(stringify!($token), token.span) + } + } + }; +} + +ident_from_token!(self); +ident_from_token!(Self); +ident_from_token!(super); +ident_from_token!(crate); +ident_from_token!(extern); + +impl From<Token![_]> for Ident { + fn from(token: Token![_]) -> Ident { + Ident::new("_", token.span) + } +} + +pub(crate) fn xid_ok(symbol: &str) -> bool { + let mut chars = symbol.chars(); + let first = chars.next().unwrap(); + if !(first == '_' || unicode_ident::is_xid_start(first)) { + return false; + } + for ch in chars { + if !unicode_ident::is_xid_continue(ch) { + return false; + } + } + true +} + +#[cfg(feature = "parsing")] +mod parsing { + use crate::buffer::Cursor; + use crate::parse::{Parse, ParseStream, Result}; + use crate::token::Token; + use proc_macro2::Ident; + + fn accept_as_ident(ident: &Ident) -> bool { + match ident.to_string().as_str() { + "_" | + // Based on https://doc.rust-lang.org/1.65.0/reference/keywords.html + "abstract" | "as" | "async" | "await" | "become" | "box" | "break" | + "const" | "continue" | "crate" | "do" | "dyn" | "else" | "enum" | + "extern" | "false" | "final" | "fn" | "for" | "if" | "impl" | "in" | + "let" | "loop" | "macro" | "match" | "mod" | "move" | "mut" | + "override" | "priv" | "pub" | "ref" | "return" | "Self" | "self" | + "static" | "struct" | "super" | "trait" | "true" | "try" | "type" | + "typeof" | "unsafe" | "unsized" | "use" | "virtual" | "where" | + "while" | "yield" => false, + _ => true, + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for Ident { + fn parse(input: ParseStream) -> Result<Self> { + input.step(|cursor| { + if let Some((ident, rest)) = cursor.ident() { + if accept_as_ident(&ident) { + Ok((ident, rest)) + } else { + Err(cursor.error(format_args!( + "expected identifier, found keyword `{}`", + ident, + ))) + } + } else { + Err(cursor.error("expected identifier")) + } + }) + } + } + + impl Token for Ident { + fn peek(cursor: Cursor) -> bool { + if let Some((ident, _rest)) = cursor.ident() { + accept_as_ident(&ident) + } else { + false + } + } + + fn display() -> &'static str { + "identifier" + } + } +} |