bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

parse: Support parsing optional literals

Browse source 
Revert weird renaming of the former `LitError::report`
This commit is contained in:
Vadim Petrochenkov 2019-11-10 15:32:41 +03:00
parent 00bc449602
commit b85a3da421
3 changed files with 27 additions and 21 deletions
Download patch file Download diff file Expand all files Collapse all files

31
src/librustc_parse/parser/expr.rs
View file

@ -778,13 +778,12 @@ impl<'a> Parser<'a> {
macro_rules! parse_lit {
() => {
match self.parse_lit() {
Ok(literal) => {
match self.parse_opt_lit() {
Some(literal) => {
hi = self.prev_span;
ex = ExprKind::Lit(literal);
}
Err(mut err) => {
err.cancel();
None => {
return Err(self.expected_expression_found());
}
}
@ -1074,11 +1073,20 @@ impl<'a> Parser<'a> {
self.maybe_recover_from_bad_qpath(expr, true)
}
/// Matches `lit = true | false | token_lit`.
pub(super) fn parse_lit(&mut self) -> PResult<'a, Lit> {
self.parse_opt_lit().ok_or_else(|| {
let msg = format!("unexpected token: {}", self.this_token_descr());
self.span_fatal(self.token.span, &msg)
})
}
/// Matches `lit = true | false | token_lit`.
/// Returns `None` if the next token is not a literal.
pub(super) fn parse_opt_lit(&mut self) -> Option<Lit> {
let mut recovered = None;
if self.token == token::Dot {
// Attempt to recover `.4` as `0.4`.
// Attempt to recover `.4` as `0.4`. We don't currently have any syntax where
// dot would follow an optional literal, so we do this unconditionally.
recovered = self.look_ahead(1, |next_token| {
if let token::Literal(token::Lit { kind: token::Integer, symbol, suffix })
= next_token.kind {
@ -1107,11 +1115,10 @@ impl<'a> Parser<'a> {
match Lit::from_token(token) {
Ok(lit) => {
self.bump();
Ok(lit)
Some(lit)
}
Err(LitError::NotLiteral) => {
let msg = format!("unexpected token: {}", self.this_token_descr());
Err(self.span_fatal(token.span, &msg))
None
}
Err(err) => {
let span = token.span;
@ -1120,18 +1127,18 @@ impl<'a> Parser<'a> {
_ => unreachable!(),
};
self.bump();
self.error_literal_from_token(err, lit, span);
self.report_lit_error(err, lit, span);
// Pack possible quotes and prefixes from the original literal into
// the error literal's symbol so they can be pretty-printed faithfully.
let suffixless_lit = token::Lit::new(lit.kind, lit.symbol, None);
let symbol = Symbol::intern(&suffixless_lit.to_string());
let lit = token::Lit::new(token::Err, symbol, lit.suffix);
Lit::from_lit_token(lit, span).map_err(|_| unreachable!())
Some(Lit::from_lit_token(lit, span).unwrap_or_else(|_| unreachable!()))
}
}
}
fn error_literal_from_token(&self, err: LitError, lit: token::Lit, span: Span) {
fn report_lit_error(&self, err: LitError, lit: token::Lit, span: Span) {
// Checks if `s` looks like i32 or u1234 etc.
fn looks_like_width_suffix(first_chars: &[char], s: &str) -> bool {
s.len() > 1