bjoernager/rust
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Make inline const work in range patterns

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This commit is contained in:
Santiago Pastorino 2020-10-19 16:18:47 -03:00
parent 954b5a81b4
commit f8842b9bac
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GPG key ID: 8131A24E0C79EFAF
2 changed files with 38 additions and 6 deletions
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21
compiler/rustc_parse/src/parser/pat.rs
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@ -315,7 +315,13 @@ impl<'a> Parser<'a> {
PatKind::Box(pat)
} else if self.check_inline_const() {
// Parse `const pat`
PatKind::Lit(self.parse_const_block(lo.to(self.token.span))?)
let const_expr = self.parse_const_block(lo.to(self.token.span))?;
if let Some(re) = self.parse_range_end() {
self.parse_pat_range_begin_with(const_expr, re)?
} else {
PatKind::Lit(const_expr)
}
} else if self.can_be_ident_pat() {
// Parse `ident @ pat`
// This can give false positives and parse nullary enums,
@ -716,17 +722,20 @@ impl<'a> Parser<'a> {
}
/// Is the token `dist` away from the current suitable as the start of a range patterns end?
fn is_pat_range_end_start(&self, dist: usize) -> bool {
self.look_ahead(dist, |t| {
t.is_path_start() // e.g. `MY_CONST`;
fn is_pat_range_end_start(&mut self, dist: usize) -> bool {
self.check_inline_const()
|| self.look_ahead(dist, |t| {
t.is_path_start() // e.g. `MY_CONST`;
|| t.kind == token::Dot // e.g. `.5` for recovery;
|| t.can_begin_literal_maybe_minus() // e.g. `42`.
|| t.is_whole_expr()
})
})
}
fn parse_pat_range_end(&mut self) -> PResult<'a, P<Expr>> {
if self.check_path() {
if self.check_inline_const() {
self.parse_const_block(self.token.span)
} else if self.check_path() {
let lo = self.token.span;
let (qself, path) = if self.eat_lt() {
// Parse a qualified path