WSL2-Linux-Kernel/rust/macros/helpers.rs

52 строки
1.4 KiB
Rust

// SPDX-License-Identifier: GPL-2.0
use proc_macro::{token_stream, TokenTree};
pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
if let Some(TokenTree::Ident(ident)) = it.next() {
Some(ident.to_string())
} else {
None
}
}
pub(crate) fn try_literal(it: &mut token_stream::IntoIter) -> Option<String> {
if let Some(TokenTree::Literal(literal)) = it.next() {
Some(literal.to_string())
} else {
None
}
}
pub(crate) fn try_byte_string(it: &mut token_stream::IntoIter) -> Option<String> {
try_literal(it).and_then(|byte_string| {
if byte_string.starts_with("b\"") && byte_string.ends_with('\"') {
Some(byte_string[2..byte_string.len() - 1].to_string())
} else {
None
}
})
}
pub(crate) fn expect_ident(it: &mut token_stream::IntoIter) -> String {
try_ident(it).expect("Expected Ident")
}
pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char {
if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") {
punct.as_char()
} else {
panic!("Expected Punct");
}
}
pub(crate) fn expect_byte_string(it: &mut token_stream::IntoIter) -> String {
try_byte_string(it).expect("Expected byte string")
}
pub(crate) fn expect_end(it: &mut token_stream::IntoIter) {
if it.next().is_some() {
panic!("Expected end");
}
}