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use crate::ast;
use crate::{
Parse, ParseError, Parser, Resolve, ResolveError, ResolveErrorKind, ResolveOwned, Spanned,
Storage, ToTokens,
};
use runestick::{Source, Span};
#[derive(Debug, Clone, PartialEq, Eq, ToTokens, Spanned)]
pub struct LitByte {
pub token: ast::Token,
#[rune(skip)]
pub source: ast::CopySource<u8>,
}
impl Parse for LitByte {
fn parse(parser: &mut Parser<'_>) -> Result<Self, ParseError> {
let token = parser.next()?;
Ok(match token.kind {
K![byte(source)] => LitByte { token, source },
_ => {
return Err(ParseError::expected(&token, "byte"));
}
})
}
}
impl<'a> Resolve<'a> for LitByte {
type Output = u8;
fn resolve(&self, _: &Storage, source: &'a Source) -> Result<u8, ResolveError> {
match self.source {
ast::CopySource::Inline(b) => return Ok(b),
ast::CopySource::Text => (),
}
let span = self.token.span();
let string = source
.source(span.trim_start(2).trim_end(1))
.ok_or_else(|| ResolveError::new(span, ResolveErrorKind::BadSlice))?;
let start = span.start.into_usize();
let mut it = string
.char_indices()
.map(|(n, c)| (start + n, c))
.peekable();
let (start, c) = match it.next() {
Some(c) => c,
None => {
return Err(ResolveError::new(span, ResolveErrorKind::BadByteLiteral));
}
};
let c = match c {
'\\' => {
let c =
match ast::utils::parse_byte_escape(&mut it, ast::utils::WithLineCont(false)) {
Ok(c) => c,
Err(kind) => {
let end = it
.next()
.map(|n| n.0)
.unwrap_or_else(|| span.end.into_usize());
return Err(ResolveError::new(Span::new(start, end), kind));
}
};
match c {
Some(c) => c,
None => {
let end = it
.next()
.map(|n| n.0)
.unwrap_or_else(|| span.end.into_usize());
return Err(ResolveError::new(
Span::new(start, end),
ResolveErrorKind::BadByteLiteral,
));
}
}
}
c if c.is_ascii() && !c.is_control() => c as u8,
_ => {
return Err(ResolveError::new(span, ResolveErrorKind::BadByteLiteral));
}
};
if it.next().is_some() {
return Err(ResolveError::new(span, ResolveErrorKind::BadByteLiteral));
}
Ok(c)
}
}
impl ResolveOwned for LitByte {
type Owned = u8;
fn resolve_owned(
&self,
storage: &Storage,
source: &Source,
) -> Result<Self::Owned, ResolveError> {
Ok(self.resolve(storage, source)?)
}
}