bevy_reflect_derive/attribute_parser.rs
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use syn::{
parse::{Parse, ParseStream, Peek},
punctuated::Punctuated,
};
/// Returns a [`syn::parse::Parser`] which parses a stream of zero or more occurrences of `T`
/// separated by punctuation of type `P`, with optional trailing punctuation.
///
/// This is functionally the same as [`Punctuated::parse_terminated`],
/// but accepts a closure rather than a function pointer.
pub(crate) fn terminated_parser<T, P, F: FnMut(ParseStream) -> syn::Result<T>>(
terminator: P,
mut parser: F,
) -> impl FnOnce(ParseStream) -> syn::Result<Punctuated<T, P::Token>>
where
P: Peek,
P::Token: Parse,
{
let _ = terminator;
move |stream: ParseStream| {
let mut punctuated = Punctuated::new();
loop {
if stream.is_empty() {
break;
}
let value = parser(stream)?;
punctuated.push_value(value);
if stream.is_empty() {
break;
}
let punct = stream.parse()?;
punctuated.push_punct(punct);
}
Ok(punctuated)
}
}