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extract parse_generic_ty_bound

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This commit is contained in:
Mazdak Farrokhzad 2019-12-08 11:19:24 +01:00
parent 1cfeb56773
commit 50e00c73ee
1 changed files with 24 additions and 15 deletions
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39
src/librustc_parse/parser/ty.rs
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@ -431,8 +431,6 @@ impl<'a> Parser<'a> {
/// ```
/// BOUND = TY_BOUND | LT_BOUND
/// LT_BOUND = LIFETIME (e.g., `'a`)
/// TY_BOUND = TY_BOUND_NOPAREN | (TY_BOUND_NOPAREN)
/// TY_BOUND_NOPAREN = [?] [for<LT_PARAM_DEFS>] SIMPLE_PATH (e.g., `?for<'a: 'b> m::Trait<'a>`)
/// ```
fn parse_generic_bound(
&mut self,
@ -454,22 +452,11 @@ impl<'a> Parser<'a> {
}
Ok(Ok(bound))
} else {
let lifetime_defs = self.parse_late_bound_lifetime_defs()?;
let path = self.parse_path(PathStyle::Type)?;
if has_parens {
self.expect(&token::CloseDelim(token::Paren))?;
}
let poly_span = lo.to(self.prev_span);
let (poly_span, bound) = self.parse_generic_ty_bound(lo, has_parens, question)?;
if is_negative {
Ok(Err(last_plus_span.or(colon_span).map(|sp| sp.to(poly_span))))
} else {
let poly_trait = PolyTraitRef::new(lifetime_defs, path, poly_span);
let modifier = if question.is_some() {
TraitBoundModifier::Maybe
} else {
TraitBoundModifier::None
};
Ok(Ok(GenericBound::Trait(poly_trait, modifier)))
Ok(Ok(bound))
}
}
}
@ -501,6 +488,28 @@ impl<'a> Parser<'a> {
Ok(())
}
/// Parses a type bound according to:
/// ```
/// TY_BOUND = TY_BOUND_NOPAREN | (TY_BOUND_NOPAREN)
/// TY_BOUND_NOPAREN = [?] [for<LT_PARAM_DEFS>] SIMPLE_PATH (e.g., `?for<'a: 'b> m::Trait<'a>`)
/// ```
fn parse_generic_ty_bound(
&mut self,
lo: Span,
has_parens: bool,
question: Option<Span>,
) -> PResult<'a, (Span, GenericBound)> {
let lifetime_defs = self.parse_late_bound_lifetime_defs()?;
let path = self.parse_path(PathStyle::Type)?;
if has_parens {
self.expect(&token::CloseDelim(token::Paren))?;
}
let poly_span = lo.to(self.prev_span);
let poly_trait = PolyTraitRef::new(lifetime_defs, path, poly_span);
let modifier = question.map_or(TraitBoundModifier::None, |_| TraitBoundModifier::Maybe);
Ok((poly_span, GenericBound::Trait(poly_trait, modifier)))
}
pub(super) fn parse_late_bound_lifetime_defs(&mut self) -> PResult<'a, Vec<GenericParam>> {
if self.eat_keyword(kw::For) {
self.expect_lt()?;