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// SPDX-License-Identifier: Apache-2.0 OR MIT #[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 == '_' || first.is_ascii_alphabetic()) {        return false;    }    for ch in chars {        if !(ch == '_' || ch.is_ascii_alphanumeric()) {            return false;        }    }    true} #[cfg(feature = "parsing")]mod parsing {    use crate::buffer::Cursor;    use crate::error::Result;    use crate::parse::{Parse, ParseStream};    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(docsrs, 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"        }    }}