diff options
| -rw-r--r-- | crates/hir-def/src/body/lower.rs | 40 | ||||
| -rw-r--r-- | crates/ide/src/signature_help.rs | 35 |
2 files changed, 56 insertions, 19 deletions
diff --git a/crates/hir-def/src/body/lower.rs b/crates/hir-def/src/body/lower.rs index acc9943481a..ebe05afca6a 100644 --- a/crates/hir-def/src/body/lower.rs +++ b/crates/hir-def/src/body/lower.rs @@ -542,9 +542,18 @@ impl ExprCollector<'_> { self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr) } ast::Expr::TupleExpr(e) => { - let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect(); + let mut exprs: Vec<_> = e.fields().map(|expr| self.collect_expr(expr)).collect(); + // if there is a leading comma, the user is most likely to type out a leading expression + // so we insert a missing expression at the beginning for IDE features + if comma_follows_token(e.l_paren_token()) { + exprs.insert(0, self.missing_expr()); + } + self.alloc_expr( - Expr::Tuple { exprs, is_assignee_expr: self.is_lowering_assignee_expr }, + Expr::Tuple { + exprs: exprs.into_boxed_slice(), + is_assignee_expr: self.is_lowering_assignee_expr, + }, syntax_ptr, ) } @@ -1180,7 +1189,11 @@ impl ExprCollector<'_> { ast::Pat::TupleStructPat(p) => { let path = p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new); - let (args, ellipsis) = self.collect_tuple_pat(p.fields(), binding_list); + let (args, ellipsis) = self.collect_tuple_pat( + p.fields(), + comma_follows_token(p.l_paren_token()), + binding_list, + ); Pat::TupleStruct { path, args, ellipsis } } ast::Pat::RefPat(p) => { @@ -1199,7 +1212,11 @@ impl ExprCollector<'_> { } ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat(), binding_list), ast::Pat::TuplePat(p) => { - let (args, ellipsis) = self.collect_tuple_pat(p.fields(), binding_list); + let (args, ellipsis) = self.collect_tuple_pat( + p.fields(), + comma_follows_token(p.l_paren_token()), + binding_list, + ); Pat::Tuple { args, ellipsis } } ast::Pat::WildcardPat(_) => Pat::Wild, @@ -1323,18 +1340,24 @@ impl ExprCollector<'_> { fn collect_tuple_pat( &mut self, args: AstChildren<ast::Pat>, + has_leading_comma: bool, binding_list: &mut BindingList, ) -> (Box<[PatId]>, Option<usize>) { // Find the location of the `..`, if there is one. Note that we do not // consider the possibility of there being multiple `..` here. let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_))); // We want to skip the `..` pattern here, since we account for it above. - let args = args + let mut args: Vec<_> = args .filter(|p| !matches!(p, ast::Pat::RestPat(_))) .map(|p| self.collect_pat(p, binding_list)) .collect(); + // if there is a leading comma, the user is most likely to type out a leading pattern + // so we insert a missing pattern at the beginning for IDE features + if has_leading_comma { + args.insert(0, self.missing_pat()); + } - (args, ellipsis) + (args.into_boxed_slice(), ellipsis) } // endregion: patterns @@ -1493,3 +1516,8 @@ impl ExprCollector<'_> { self.body.labels.alloc(label) } } + +fn comma_follows_token(t: Option<syntax::SyntaxToken>) -> bool { + (|| syntax::algo::skip_trivia_token(t?.next_token()?, syntax::Direction::Next))() + .map_or(false, |it| it.kind() == syntax::T![,]) +} diff --git a/crates/ide/src/signature_help.rs b/crates/ide/src/signature_help.rs index 9bd9a948e7f..7795be54e26 100644 --- a/crates/ide/src/signature_help.rs +++ b/crates/ide/src/signature_help.rs @@ -1996,7 +1996,6 @@ fn main() { #[test] fn test_tuple_expr_expected() { - // FIXME: Seems like we discard valuable results in typeck here check( r#" fn main() { @@ -2004,19 +2003,20 @@ fn main() { } "#, expect![[r#" - (&str, u32) - ^^^^ --- + (&str, u32, u32) + ^^^^ --- --- "#]], ); + // FIXME: Should typeck report a 4-ary tuple for the expression here? check( r#" fn main() { - let _: (&str, u32, u32, u32)= ($0, 1, 3); + let _: (&str, u32, u32, u32) = ($0, 1, 3); } "#, expect![[r#" - (&str, u32) - ^^^^ --- + (&str, u32, u32) + ^^^^ --- --- "#]], ); check( @@ -2026,15 +2026,25 @@ fn main() { } "#, expect![[r#" - (&str, u32, u32) - ^^^^ --- --- + (&str, u32, u32, i32) + ^^^^ --- --- --- "#]], ); } #[test] fn test_tuple_pat_free() { - // FIXME: Seems like we discard valuable results in typeck here + check( + r#" +fn main() { + let ($0, 1, 3); +} +"#, + expect![[r#" + ({unknown}, i32, i32) + ^^^^^^^^^ --- --- + "#]], + ); check( r#" fn main() { @@ -2123,10 +2133,9 @@ fn main() { let ($0, 1, 3): (i32, i32, i32); } "#, - // FIXME: tuple pat should be of size 3 ideally expect![[r#" - (i32, i32) - ^^^ --- + (i32, i32, i32) + ^^^ --- --- "#]], ); check( @@ -2182,7 +2191,7 @@ fn main() { let ($0 1, 3) = (1, 2, 3); } "#, - // FIXME: tuple pat should be of size 3 ideally + // FIXME: Should typeck report a 3-ary tuple for the pattern here? expect![[r#" (i32, i32) ^^^ --- |