Revision control
Copy as Markdown
Other Tools
#[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::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() {
"_" |
"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"
}
}
}