From bdccbcf41bd881806d5370b8c7fe05e90143a076 Mon Sep 17 00:00:00 2001 From: Manish Goregaokar Date: Fri, 23 Feb 2018 12:39:51 -0800 Subject: parse `dyn (Foo)` as a trait object --- src/libsyntax/parse/parser.rs | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'src/libsyntax/parse') diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 74daa5179d3..f798855d0e0 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -405,11 +405,14 @@ impl TokenType { } } -// Returns true if `IDENT t` can start a type - `IDENT::a::b`, `IDENT`, -// `IDENT<::AssocTy>`, `IDENT(u8, u8) -> u8`. -fn can_continue_type_after_ident(t: &token::Token) -> bool { +/// Returns true if `IDENT t` can start a type - `IDENT::a::b`, `IDENT`, +/// `IDENT<::AssocTy>`. +/// +/// Types can also be of the form `IDENT(u8, u8) -> u8`, however this assumes +/// that IDENT is not the ident of a fn trait +fn can_continue_type_after_non_fn_ident(t: &token::Token) -> bool { t == &token::ModSep || t == &token::Lt || - t == &token::BinOp(token::Shl) || t == &token::OpenDelim(token::Paren) + t == &token::BinOp(token::Shl) } /// Information about the path to a module. @@ -1619,7 +1622,8 @@ impl<'a> Parser<'a> { impl_dyn_multi = bounds.len() > 1 || self.prev_token_kind == PrevTokenKind::Plus; TyKind::ImplTrait(bounds) } else if self.check_keyword(keywords::Dyn) && - self.look_ahead(1, |t| t.can_begin_bound() && !can_continue_type_after_ident(t)) { + self.look_ahead(1, |t| t.can_begin_bound() && + !can_continue_type_after_non_fn_ident(t)) { self.bump(); // `dyn` // Always parse bounds greedily for better error recovery. let bounds = self.parse_ty_param_bounds()?; -- cgit 1.4.1-3-g733a5