24 files changed, 556 insertions, 144 deletions

diff --git a/crates/ra_assists/src/handlers/merge_imports.rs b/crates/ra_assists/src/handlers/merge_imports.rs
index 0958f52f1..ef0ce0586 100644
--- a/crates/ra_assists/src/handlers/merge_imports.rs
+++ b/crates/ra_assists/src/handlers/merge_imports.rs
@@ -1,7 +1,7 @@
 use std::iter::successors;
 
 use ra_syntax::{
-    algo::{neighbor, SyntaxRewriter},
+    algo::{neighbor, skip_trivia_token, SyntaxRewriter},
     ast::{self, edit::AstNodeEdit, make},
     AstNode, Direction, InsertPosition, SyntaxElement, T,
 };
@@ -72,9 +72,18 @@ fn try_merge_trees(old: &ast::UseTree, new: &ast::UseTree) -> Option<ast::UseTre
     let lhs = old.split_prefix(&lhs_prefix);
     let rhs = new.split_prefix(&rhs_prefix);
 
+    let should_insert_comma = lhs
+        .use_tree_list()?
+        .r_curly_token()
+        .and_then(|it| skip_trivia_token(it.prev_token()?, Direction::Prev))
+        .map(|it| it.kind() != T![,])
+        .unwrap_or(true);
+
     let mut to_insert: Vec<SyntaxElement> = Vec::new();
-    to_insert.push(make::token(T![,]).into());
-    to_insert.push(make::tokens::single_space().into());
+    if should_insert_comma {
+        to_insert.push(make::token(T![,]).into());
+        to_insert.push(make::tokens::single_space().into());
+    }
     to_insert.extend(
         rhs.use_tree_list()?
             .syntax()
@@ -247,4 +256,22 @@ use {
 ",
         );
     }
+
+    #[test]
+    fn test_double_comma() {
+        check_assist(
+            merge_imports,
+            r"
+use foo::bar::baz;
+use foo::<|>{
+    FooBar,
+};
+",
+            r"
+use foo::{<|>
+    FooBar,
+bar::baz};
+",
+        )
+    }
 }
diff --git a/crates/ra_assists/src/handlers/reorder_fields.rs b/crates/ra_assists/src/handlers/reorder_fields.rs
index 692dd1315..5cbb98d73 100644
--- a/crates/ra_assists/src/handlers/reorder_fields.rs
+++ b/crates/ra_assists/src/handlers/reorder_fields.rs
@@ -1,20 +1,20 @@
 use std::collections::HashMap;
 
-use itertools::Itertools;
-
 use hir::{Adt, ModuleDef, PathResolution, Semantics, Struct};
+use itertools::Itertools;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
-    algo, ast,
-    ast::{Name, Path, RecordLit, RecordPat},
-    AstNode, SyntaxKind, SyntaxNode,
+    algo,
+    ast::{self, Path, RecordLit, RecordPat},
+    match_ast, AstNode, SyntaxKind,
+    SyntaxKind::*,
+    SyntaxNode,
 };
 
 use crate::{
     assist_ctx::{Assist, AssistCtx},
     AssistId,
 };
-use ra_syntax::ast::{Expr, NameRef};
 
 // Assist: reorder_fields
 //
@@ -59,7 +59,6 @@ fn reorder<R: AstNode>(ctx: AssistCtx) -> Option<Assist> {
 }
 
 fn get_fields_kind(node: &SyntaxNode) -> Vec<SyntaxKind> {
-    use SyntaxKind::*;
     match node.kind() {
         RECORD_LIT => vec![RECORD_FIELD],
         RECORD_PAT => vec![RECORD_FIELD_PAT, BIND_PAT],
@@ -68,19 +67,14 @@ fn get_fields_kind(node: &SyntaxNode) -> Vec<SyntaxKind> {
 }
 
 fn get_field_name(node: &SyntaxNode) -> String {
-    use SyntaxKind::*;
-    match node.kind() {
-        RECORD_FIELD => {
-            if let Some(name) = node.children().find_map(NameRef::cast) {
-                return name.to_string();
-            }
-            node.children().find_map(Expr::cast).map(|expr| expr.to_string()).unwrap_or_default()
-        }
-        BIND_PAT | RECORD_FIELD_PAT => {
-            node.children().find_map(Name::cast).map(|n| n.to_string()).unwrap_or_default()
+    let res = match_ast! {
+        match node {
+            ast::RecordField(field) => field.field_name().map(|it| it.to_string()),
+            ast::RecordFieldPat(field) => field.field_name().map(|it| it.to_string()),
+            _ => None,
         }
-        _ => String::new(),
-    }
+    };
+    res.unwrap_or_default()
 }
 
 fn get_fields(record: &SyntaxNode) -> Vec<SyntaxNode> {
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index c057dc8f2..79abe55ce 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -33,6 +33,7 @@ use crate::{
 };
 
 use super::{ExprSource, PatSource};
+use ast::AstChildren;
 
 pub(super) fn lower(
     db: &dyn DefDatabase,
@@ -598,8 +599,8 @@ impl ExprCollector<'_> {
             }
             ast::Pat::TupleStructPat(p) => {
                 let path = p.path().and_then(|path| self.expander.parse_path(path));
-                let args = p.args().map(|p| self.collect_pat(p)).collect();
-                Pat::TupleStruct { path, args }
+                let (args, ellipsis) = self.collect_tuple_pat(p.args());
+                Pat::TupleStruct { path, args, ellipsis }
             }
             ast::Pat::RefPat(p) => {
                 let pat = self.collect_pat_opt(p.pat());
@@ -616,10 +617,10 @@ impl ExprCollector<'_> {
             }
             ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat()),
             ast::Pat::TuplePat(p) => {
-                let args = p.args().map(|p| self.collect_pat(p)).collect();
-                Pat::Tuple(args)
+                let (args, ellipsis) = self.collect_tuple_pat(p.args());
+                Pat::Tuple { args, ellipsis }
             }
-            ast::Pat::PlaceholderPat(_) | ast::Pat::DotDotPat(_) => Pat::Wild,
+            ast::Pat::PlaceholderPat(_) => Pat::Wild,
             ast::Pat::RecordPat(p) => {
                 let path = p.path().and_then(|path| self.expander.parse_path(path));
                 let record_field_pat_list =
@@ -637,7 +638,7 @@ impl ExprCollector<'_> {
                 let iter = record_field_pat_list.record_field_pats().filter_map(|f| {
                     let ast_pat = f.pat()?;
                     let pat = self.collect_pat(ast_pat);
-                    let name = f.name()?.as_name();
+                    let name = f.field_name()?.as_name();
                     Some(RecordFieldPat { name, pat })
                 });
                 fields.extend(iter);
@@ -665,6 +666,9 @@ impl ExprCollector<'_> {
                     Pat::Missing
                 }
             }
+            ast::Pat::DotDotPat(_) => unreachable!(
+                "`DotDotPat` requires special handling and should not be mapped to a Pat."
+            ),
             // FIXME: implement
             ast::Pat::BoxPat(_) | ast::Pat::RangePat(_) | ast::Pat::MacroPat(_) => Pat::Missing,
         };
@@ -679,6 +683,19 @@ impl ExprCollector<'_> {
             self.missing_pat()
         }
     }
+
+    fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Vec<PatId>, Option<usize>) {
+        // Find the location of the `..`, if there is one. Note that we do not
+        // consider the possiblity of there being multiple `..` here.
+        let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::DotDotPat(_)));
+        // We want to skip the `..` pattern here, since we account for it above.
+        let args = args
+            .filter(|p| !matches!(p, ast::Pat::DotDotPat(_)))
+            .map(|p| self.collect_pat(p))
+            .collect();
+
+        (args, ellipsis)
+    }
 }
 
 impl From<ast::BinOp> for BinaryOp {
diff --git a/crates/ra_hir_def/src/expr.rs b/crates/ra_hir_def/src/expr.rs
index e11bdf3ec..a0cdad529 100644
--- a/crates/ra_hir_def/src/expr.rs
+++ b/crates/ra_hir_def/src/expr.rs
@@ -374,7 +374,7 @@ pub struct RecordFieldPat {
 pub enum Pat {
     Missing,
     Wild,
-    Tuple(Vec<PatId>),
+    Tuple { args: Vec<PatId>, ellipsis: Option<usize> },
     Or(Vec<PatId>),
     Record { path: Option<Path>, args: Vec<RecordFieldPat>, ellipsis: bool },
     Range { start: ExprId, end: ExprId },
@@ -382,7 +382,7 @@ pub enum Pat {
     Path(Path),
     Lit(ExprId),
     Bind { mode: BindingAnnotation, name: Name, subpat: Option<PatId> },
-    TupleStruct { path: Option<Path>, args: Vec<PatId> },
+    TupleStruct { path: Option<Path>, args: Vec<PatId>, ellipsis: Option<usize> },
     Ref { pat: PatId, mutability: Mutability },
 }
 
@@ -393,7 +393,7 @@ impl Pat {
             Pat::Bind { subpat, .. } => {
                 subpat.iter().copied().for_each(f);
             }
-            Pat::Or(args) | Pat::Tuple(args) | Pat::TupleStruct { args, .. } => {
+            Pat::Or(args) | Pat::Tuple { args, .. } | Pat::TupleStruct { args, .. } => {
                 args.iter().copied().for_each(f);
             }
             Pat::Ref { pat, .. } => f(*pat),
diff --git a/crates/ra_hir_expand/src/name.rs b/crates/ra_hir_expand/src/name.rs
index 25cc1e9fc..fecce224e 100644
--- a/crates/ra_hir_expand/src/name.rs
+++ b/crates/ra_hir_expand/src/name.rs
@@ -83,6 +83,15 @@ impl AsName for ast::Name {
     }
 }
 
+impl AsName for ast::NameOrNameRef {
+    fn as_name(&self) -> Name {
+        match self {
+            ast::NameOrNameRef::Name(it) => it.as_name(),
+            ast::NameOrNameRef::NameRef(it) => it.as_name(),
+        }
+    }
+}
+
 impl AsName for tt::Ident {
     fn as_name(&self) -> Name {
         Name::resolve(&self.text)
diff --git a/crates/ra_hir_ty/src/_match.rs b/crates/ra_hir_ty/src/_match.rs
index 9e9a9d047..a64be9848 100644
--- a/crates/ra_hir_ty/src/_match.rs
+++ b/crates/ra_hir_ty/src/_match.rs
@@ -289,7 +289,7 @@ impl PatStack {
         Self::from_slice(&self.0[1..])
     }
 
-    fn replace_head_with(&self, pat_ids: &[PatId]) -> PatStack {
+    fn replace_head_with<T: Into<PatIdOrWild> + Copy>(&self, pat_ids: &[T]) -> PatStack {
         let mut patterns: PatStackInner = smallvec![];
         for pat in pat_ids {
             patterns.push((*pat).into());
@@ -320,12 +320,14 @@ impl PatStack {
         constructor: &Constructor,
     ) -> MatchCheckResult<Option<PatStack>> {
         let result = match (self.head().as_pat(cx), constructor) {
-            (Pat::Tuple(ref pat_ids), Constructor::Tuple { arity }) => {
-                debug_assert_eq!(
-                    pat_ids.len(),
-                    *arity,
-                    "we type check before calling this code, so we should never hit this case",
-                );
+            (Pat::Tuple { args: ref pat_ids, ellipsis }, Constructor::Tuple { arity: _ }) => {
+                if ellipsis.is_some() {
+                    // If there are ellipsis here, we should add the correct number of
+                    // Pat::Wild patterns to `pat_ids`. We should be able to use the
+                    // constructors arity for this, but at the time of writing we aren't
+                    // correctly calculating this arity when ellipsis are present.
+                    return Err(MatchCheckErr::NotImplemented);
+                }
 
                 Some(self.replace_head_with(pat_ids))
             }
@@ -351,19 +353,47 @@ impl PatStack {
                     Some(self.to_tail())
                 }
             }
-            (Pat::TupleStruct { args: ref pat_ids, .. }, Constructor::Enum(enum_constructor)) => {
+            (
+                Pat::TupleStruct { args: ref pat_ids, ellipsis, .. },
+                Constructor::Enum(enum_constructor),
+            ) => {
                 let pat_id = self.head().as_id().expect("we know this isn't a wild");
                 if !enum_variant_matches(cx, pat_id, *enum_constructor) {
                     None
                 } else {
-                    // If the enum variant matches, then we need to confirm
-                    // that the number of patterns aligns with the expected
-                    // number of patterns for that enum variant.
-                    if pat_ids.len() != constructor.arity(cx)? {
-                        return Err(MatchCheckErr::MalformedMatchArm);
+                    let constructor_arity = constructor.arity(cx)?;
+                    if let Some(ellipsis_position) = ellipsis {
+                        // If there are ellipsis in the pattern, the ellipsis must take the place
+                        // of at least one sub-pattern, so `pat_ids` should be smaller than the
+                        // constructor arity.
+                        if pat_ids.len() < constructor_arity {
+                            let mut new_patterns: Vec<PatIdOrWild> = vec![];
+
+                            for pat_id in &pat_ids[0..ellipsis_position] {
+                                new_patterns.push((*pat_id).into());
+                            }
+
+                            for _ in 0..(constructor_arity - pat_ids.len()) {
+                                new_patterns.push(PatIdOrWild::Wild);
+                            }
+
+                            for pat_id in &pat_ids[ellipsis_position..pat_ids.len()] {
+                                new_patterns.push((*pat_id).into());
+                            }
+
+                            Some(self.replace_head_with(&new_patterns))
+                        } else {
+                            return Err(MatchCheckErr::MalformedMatchArm);
+                        }
+                    } else {
+                        // If there is no ellipsis in the tuple pattern, the number
+                        // of patterns must equal the constructor arity.
+                        if pat_ids.len() == constructor_arity {
+                            Some(self.replace_head_with(pat_ids))
+                        } else {
+                            return Err(MatchCheckErr::MalformedMatchArm);
+                        }
                     }
-
-                    Some(self.replace_head_with(pat_ids))
                 }
             }
             (Pat::Or(_), _) => return Err(MatchCheckErr::NotImplemented),
@@ -644,7 +674,11 @@ impl Constructor {
 fn pat_constructor(cx: &MatchCheckCtx, pat: PatIdOrWild) -> MatchCheckResult<Option<Constructor>> {
     let res = match pat.as_pat(cx) {
         Pat::Wild => None,
-        Pat::Tuple(pats) => Some(Constructor::Tuple { arity: pats.len() }),
+        // FIXME somehow create the Tuple constructor with the proper arity. If there are
+        // ellipsis, the arity is not equal to the number of patterns.
+        Pat::Tuple { args: pats, ellipsis } if ellipsis.is_none() => {
+            Some(Constructor::Tuple { arity: pats.len() })
+        }
         Pat::Lit(lit_expr) => match cx.body.exprs[lit_expr] {
             Expr::Literal(Literal::Bool(val)) => Some(Constructor::Bool(val)),
             _ => return Err(MatchCheckErr::NotImplemented),
@@ -973,6 +1007,47 @@ mod tests {
     }
 
     #[test]
+    fn tuple_of_bools_with_ellipsis_at_end_no_diagnostic() {
+        let content = r"
+            fn test_fn() {
+                match (false, true, false) {
+                    (false, ..) => {},
+                    (true, ..) => {},
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn tuple_of_bools_with_ellipsis_at_beginning_no_diagnostic() {
+        let content = r"
+            fn test_fn() {
+                match (false, true, false) {
+                    (.., false) => {},
+                    (.., true) => {},
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn tuple_of_bools_with_ellipsis_no_diagnostic() {
+        let content = r"
+            fn test_fn() {
+                match (false, true, false) {
+                    (..) => {},
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
     fn tuple_of_tuple_and_bools_no_arms() {
         let content = r"
             fn test_fn() {
@@ -1315,8 +1390,9 @@ mod tests {
             }
         ";
 
-        // Match arms with the incorrect type are filtered out.
-        check_diagnostic(content);
+        // Match statements with arms that don't match the
+        // expression pattern do not fire this diagnostic.
+        check_no_diagnostic(content);
     }
 
     #[test]
@@ -1330,8 +1406,9 @@ mod tests {
             }
         ";
 
-        // Match arms with the incorrect type are filtered out.
-        check_diagnostic(content);
+        // Match statements with arms that don't match the
+        // expression pattern do not fire this diagnostic.
+        check_no_diagnostic(content);
     }
 
     #[test]
@@ -1344,8 +1421,9 @@ mod tests {
             }
         ";
 
-        // Match arms with the incorrect type are filtered out.
-        check_diagnostic(content);
+        // Match statements with arms that don't match the
+        // expression pattern do not fire this diagnostic.
+        check_no_diagnostic(content);
     }
 
     #[test]
@@ -1383,6 +1461,163 @@ mod tests {
         // we don't create a diagnostic).
         check_no_diagnostic(content);
     }
+
+    #[test]
+    fn expr_diverges() {
+        let content = r"
+            enum Either {
+                A,
+                B,
+            }
+            fn test_fn() {
+                match loop {} {
+                    Either::A => (),
+                    Either::B => (),
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn expr_loop_with_break() {
+        let content = r"
+            enum Either {
+                A,
+                B,
+            }
+            fn test_fn() {
+                match loop { break Foo::A } {
+                    Either::A => (),
+                    Either::B => (),
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn expr_partially_diverges() {
+        let content = r"
+            enum Either<T> {
+                A(T),
+                B,
+            }
+            fn foo() -> Either<!> {
+                Either::B
+            }
+            fn test_fn() -> u32 {
+                match foo() {
+                    Either::A(val) => val,
+                    Either::B => 0,
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_tuple_partial_ellipsis_no_diagnostic() {
+        let content = r"
+            enum Either {
+                A(bool, bool, bool, bool),
+                B,
+            }
+            fn test_fn() {
+                match Either::B {
+                    Either::A(true, .., true) => {},
+                    Either::A(true, .., false) => {},
+                    Either::A(false, .., true) => {},
+                    Either::A(false, .., false) => {},
+                    Either::B => {},
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_tuple_partial_ellipsis_2_no_diagnostic() {
+        let content = r"
+            enum Either {
+                A(bool, bool, bool, bool),
+                B,
+            }
+            fn test_fn() {
+                match Either::B {
+                    Either::A(true, .., true) => {},
+                    Either::A(true, .., false) => {},
+                    Either::A(.., true) => {},
+                    Either::A(.., false) => {},
+                    Either::B => {},
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_tuple_partial_ellipsis_missing_arm() {
+        let content = r"
+            enum Either {
+                A(bool, bool, bool, bool),
+                B,
+            }
+            fn test_fn() {
+                match Either::B {
+                    Either::A(true, .., true) => {},
+                    Either::A(true, .., false) => {},
+                    Either::A(false, .., false) => {},
+                    Either::B => {},
+                }
+            }
+        ";
+
+        check_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_tuple_partial_ellipsis_2_missing_arm() {
+        let content = r"
+            enum Either {
+                A(bool, bool, bool, bool),
+                B,
+            }
+            fn test_fn() {
+                match Either::B {
+                    Either::A(true, .., true) => {},
+                    Either::A(true, .., false) => {},
+                    Either::A(.., true) => {},
+                    Either::B => {},
+                }
+            }
+        ";
+
+        check_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_tuple_ellipsis_no_diagnostic() {
+        let content = r"
+            enum Either {
+                A(bool, bool, bool, bool),
+                B,
+            }
+            fn test_fn() {
+                match Either::B {
+                    Either::A(..) => {},
+                    Either::B => {},
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
 }
 
 #[cfg(test)]
@@ -1452,4 +1687,75 @@ mod false_negatives {
         // We do not currently handle patterns with internal `or`s.
         check_no_diagnostic(content);
     }
+
+    #[test]
+    fn expr_diverges_missing_arm() {
+        let content = r"
+            enum Either {
+                A,
+                B,
+            }
+            fn test_fn() {
+                match loop {} {
+                    Either::A => (),
+                }
+            }
+        ";
+
+        // This is a false negative.
+        // Even though the match expression diverges, rustc fails
+        // to compile here since `Either::B` is missing.
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn expr_loop_missing_arm() {
+        let content = r"
+            enum Either {
+                A,
+                B,
+            }
+            fn test_fn() {
+                match loop { break Foo::A } {
+                    Either::A => (),
+                }
+            }
+        ";
+
+        // This is a false negative.
+        // We currently infer the type of `loop { break Foo::A }` to `!`, which
+        // causes us to skip the diagnostic since `Either::A` doesn't type check
+        // with `!`.
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn tuple_of_bools_with_ellipsis_at_end_missing_arm() {
+        let content = r"
+            fn test_fn() {
+                match (false, true, false) {
+                    (false, ..) => {},
+                }
+            }
+        ";
+
+        // This is a false negative.
+        // We don't currently handle tuple patterns with ellipsis.
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn tuple_of_bools_with_ellipsis_at_beginning_missing_arm() {
+        let content = r"
+            fn test_fn() {
+                match (false, true, false) {
+                    (.., false) => {},
+                }
+            }
+        ";
+
+        // This is a false negative.
+        // We don't currently handle tuple patterns with ellipsis.
+        check_no_diagnostic(content);
+    }
 }
diff --git a/crates/ra_hir_ty/src/expr.rs b/crates/ra_hir_ty/src/expr.rs
index 69b527f74..21abbcf1e 100644
--- a/crates/ra_hir_ty/src/expr.rs
+++ b/crates/ra_hir_ty/src/expr.rs
@@ -161,12 +161,6 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
 
         let mut seen = Matrix::empty();
         for pat in pats {
-            // We skip any patterns whose type we cannot resolve.
-            //
-            // This could lead to false positives in this diagnostic, so
-            // it might be better to skip the entire diagnostic if we either
-            // cannot resolve a match arm or determine that the match arm has
-            // the wrong type.
             if let Some(pat_ty) = infer.type_of_pat.get(pat) {
                 // We only include patterns whose type matches the type
                 // of the match expression. If we had a InvalidMatchArmPattern
@@ -189,8 +183,15 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
                     // to the matrix here.
                     let v = PatStack::from_pattern(pat);
                     seen.push(&cx, v);
+                    continue;
                 }
             }
+
+            // If we can't resolve the type of a pattern, or the pattern type doesn't
+            // fit the match expression, we skip this diagnostic. Skipping the entire
+            // diagnostic rather than just not including this match arm is preferred
+            // to avoid the chance of false positives.
+            return;
         }
 
         match is_useful(&cx, &seen, &PatStack::from_wild()) {
diff --git a/crates/ra_hir_ty/src/infer/pat.rs b/crates/ra_hir_ty/src/infer/pat.rs
index 078476f76..8ec4d4ace 100644
--- a/crates/ra_hir_ty/src/infer/pat.rs
+++ b/crates/ra_hir_ty/src/infer/pat.rs
@@ -85,7 +85,7 @@ impl<'a> InferenceContext<'a> {
         let body = Arc::clone(&self.body); // avoid borrow checker problem
 
         let is_non_ref_pat = match &body[pat] {
-            Pat::Tuple(..)
+            Pat::Tuple { .. }
             | Pat::Or(..)
             | Pat::TupleStruct { .. }
             | Pat::Record { .. }
@@ -116,7 +116,7 @@ impl<'a> InferenceContext<'a> {
         let expected = expected;
 
         let ty = match &body[pat] {
-            Pat::Tuple(ref args) => {
+            Pat::Tuple { ref args, .. } => {
                 let expectations = match expected.as_tuple() {
                     Some(parameters) => &*parameters.0,
                     _ => &[],
@@ -155,7 +155,7 @@ impl<'a> InferenceContext<'a> {
                 let subty = self.infer_pat(*pat, expectation, default_bm);
                 Ty::apply_one(TypeCtor::Ref(*mutability), subty)
             }
-            Pat::TupleStruct { path: p, args: subpats } => {
+            Pat::TupleStruct { path: p, args: subpats, .. } => {
                 self.infer_tuple_struct_pat(p.as_ref(), subpats, expected, default_bm, pat)
             }
             Pat::Record { path: p, args: fields, ellipsis: _ } => {
diff --git a/crates/ra_hir_ty/src/tests/patterns.rs b/crates/ra_hir_ty/src/tests/patterns.rs
index 6e5d2247c..07cbc521a 100644
--- a/crates/ra_hir_ty/src/tests/patterns.rs
+++ b/crates/ra_hir_ty/src/tests/patterns.rs
@@ -1,7 +1,8 @@
-use super::{infer, infer_with_mismatches};
 use insta::assert_snapshot;
 use test_utils::covers;
 
+use super::{infer, infer_with_mismatches};
+
 #[test]
 fn infer_pattern() {
     assert_snapshot!(
diff --git a/crates/ra_ide/src/call_info.rs b/crates/ra_ide/src/call_info.rs
index ca57eceff..f95b6baf3 100644
--- a/crates/ra_ide/src/call_info.rs
+++ b/crates/ra_ide/src/call_info.rs
@@ -208,9 +208,20 @@ mod tests {
         }
     }
 
-    fn call_info(text: &str) -> CallInfo {
+    fn call_info_helper(text: &str) -> Option<CallInfo> {
         let (analysis, position) = single_file_with_position(text);
-        analysis.call_info(position).unwrap().unwrap()
+        analysis.call_info(position).unwrap()
+    }
+
+    fn call_info(text: &str) -> CallInfo {
+        let info = call_info_helper(text);
+        assert!(info.is_some());
+        info.unwrap()
+    }
+
+    fn no_call_info(text: &str) {
+        let info = call_info_helper(text);
+        assert!(info.is_none());
     }
 
     #[test]
@@ -558,9 +569,8 @@ fn main() {
     }
 
     #[test]
-    #[should_panic]
     fn cant_call_named_structs() {
-        let _ = call_info(
+        no_call_info(
             r#"
 struct TS { x: u32, y: i32 }
 fn main() {
@@ -594,9 +604,8 @@ fn main() {
     }
 
     #[test]
-    #[should_panic]
     fn cant_call_enum_records() {
-        let _ = call_info(
+        no_call_info(
             r#"
 enum E {
     /// A Variant
diff --git a/crates/ra_ide/src/completion/complete_pattern.rs b/crates/ra_ide/src/completion/complete_pattern.rs
index 1b7d3122f..a8b4ce114 100644
--- a/crates/ra_ide/src/completion/complete_pattern.rs
+++ b/crates/ra_ide/src/completion/complete_pattern.rs
@@ -7,6 +7,10 @@ pub(super) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
     if !ctx.is_pat_binding_or_const {
         return;
     }
+    if ctx.record_pat_syntax.is_some() {
+        return;
+    }
+
     // FIXME: ideally, we should look at the type we are matching against and
     // suggest variants + auto-imports
     ctx.scope().process_all_names(&mut |name, res| {
diff --git a/crates/ra_ide/src/completion/complete_record.rs b/crates/ra_ide/src/completion/complete_record.rs
index f46bcee5c..83a553155 100644
--- a/crates/ra_ide/src/completion/complete_record.rs
+++ b/crates/ra_ide/src/completion/complete_record.rs
@@ -2,7 +2,7 @@
 use crate::completion::{CompletionContext, Completions};
 
 pub(super) fn complete_record(acc: &mut Completions, ctx: &CompletionContext) -> Option<()> {
-    let missing_fields = match (ctx.record_lit_pat.as_ref(), ctx.record_lit_syntax.as_ref()) {
+    let missing_fields = match (ctx.record_pat_syntax.as_ref(), ctx.record_lit_syntax.as_ref()) {
         (None, None) => return None,
         (Some(_), Some(_)) => unreachable!("A record cannot be both a literal and a pattern"),
         (Some(record_pat), _) => ctx.sema.record_pattern_missing_fields(record_pat),
diff --git a/crates/ra_ide/src/completion/complete_unqualified_path.rs b/crates/ra_ide/src/completion/complete_unqualified_path.rs
index 0b0da6ee4..2d8e0776c 100644
--- a/crates/ra_ide/src/completion/complete_unqualified_path.rs
+++ b/crates/ra_ide/src/completion/complete_unqualified_path.rs
@@ -3,7 +3,14 @@
 use crate::completion::{CompletionContext, Completions};
 
 pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionContext) {
-    if !(ctx.is_trivial_path && !ctx.is_pat_binding_or_const && !ctx.record_lit_syntax.is_some()) {
+    if !ctx.is_trivial_path {
+        return;
+    }
+
+    if ctx.is_pat_binding_or_const
+        || ctx.record_lit_syntax.is_some()
+        || ctx.record_pat_syntax.is_some()
+    {
         return;
     }
 
diff --git a/crates/ra_ide/src/completion/completion_context.rs b/crates/ra_ide/src/completion/completion_context.rs
index eb8016dd1..da054f7a2 100644
--- a/crates/ra_ide/src/completion/completion_context.rs
+++ b/crates/ra_ide/src/completion/completion_context.rs
@@ -31,7 +31,7 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) function_syntax: Option<ast::FnDef>,
     pub(super) use_item_syntax: Option<ast::UseItem>,
     pub(super) record_lit_syntax: Option<ast::RecordLit>,
-    pub(super) record_lit_pat: Option<ast::RecordPat>,
+    pub(super) record_pat_syntax: Option<ast::RecordPat>,
     pub(super) impl_def: Option<ast::ImplDef>,
     pub(super) call_info: Option<CallInfo>,
     pub(super) is_param: bool,
@@ -97,7 +97,7 @@ impl<'a> CompletionContext<'a> {
             call_info: None,
             use_item_syntax: None,
             record_lit_syntax: None,
-            record_lit_pat: None,
+            record_pat_syntax: None,
             impl_def: None,
             is_param: false,
             is_pat_binding_or_const: false,
@@ -186,6 +186,11 @@ impl<'a> CompletionContext<'a> {
                 self.is_param = true;
                 return;
             }
+            // FIXME: remove this (V) duplication and make the check more precise
+            if name_ref.syntax().ancestors().find_map(ast::RecordFieldPatList::cast).is_some() {
+                self.record_pat_syntax =
+                    self.sema.find_node_at_offset_with_macros(&original_file, offset);
+            }
             self.classify_name_ref(original_file, name_ref, offset);
         }
 
@@ -215,8 +220,9 @@ impl<'a> CompletionContext<'a> {
                 self.is_param = true;
                 return;
             }
+            // FIXME: remove this (^) duplication and make the check more precise
             if name.syntax().ancestors().find_map(ast::RecordFieldPatList::cast).is_some() {
-                self.record_lit_pat =
+                self.record_pat_syntax =
                     self.sema.find_node_at_offset_with_macros(&original_file, offset);
             }
         }
diff --git a/crates/ra_parser/src/grammar.rs b/crates/ra_parser/src/grammar.rs
index d0530955e..c2a6e82e9 100644
--- a/crates/ra_parser/src/grammar.rs
+++ b/crates/ra_parser/src/grammar.rs
@@ -282,13 +282,10 @@ fn name_ref(p: &mut Parser) {
 }
 
 fn name_ref_or_index(p: &mut Parser) {
-    if p.at(IDENT) || p.at(INT_NUMBER) {
-        let m = p.start();
-        p.bump_any();
-        m.complete(p, NAME_REF);
-    } else {
-        p.err_and_bump("expected identifier");
-    }
+    assert!(p.at(IDENT) || p.at(INT_NUMBER));
+    let m = p.start();
+    p.bump_any();
+    m.complete(p, NAME_REF);
 }
 
 fn error_block(p: &mut Parser, message: &str) {
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index 936d27575..68fb2fc73 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -192,14 +192,30 @@ fn record_field_pat_list(p: &mut Parser) {
         match p.current() {
             // A trailing `..` is *not* treated as a DOT_DOT_PAT.
             T![.] if p.at(T![..]) => p.bump(T![..]),
-
-            IDENT | INT_NUMBER if p.nth(1) == T![:] => record_field_pat(p),
             T!['{'] => error_block(p, "expected ident"),
-            T![box] => {
-                box_pat(p);
-            }
-            _ => {
-                bind_pat(p, false);
+
+            c => {
+                let m = p.start();
+                match c {
+                    // test record_field_pat
+                    // fn foo() {
+                    //     let S { 0: 1 } = ();
+                    //     let S { x: 1 } = ();
+                    // }
+                    IDENT | INT_NUMBER if p.nth(1) == T![:] => {
+                        name_ref_or_index(p);
+                        p.bump(T![:]);
+                        pattern(p);
+                    }
+                    T![box] => {
+                        // FIXME: not all box patterns should be allowed
+                        box_pat(p);
+                    }
+                    _ => {
+                        bind_pat(p, false);
+                    }
+                }
+                m.complete(p, RECORD_FIELD_PAT);
             }
         }
         if !p.at(T!['}']) {
@@ -210,26 +226,6 @@ fn record_field_pat_list(p: &mut Parser) {
     m.complete(p, RECORD_FIELD_PAT_LIST);
 }
 
-// test record_field_pat
-// fn foo() {
-//     let S { 0: 1 } = ();
-//     let S { x: 1 } = ();
-// }
-fn record_field_pat(p: &mut Parser) {
-    assert!(p.at(IDENT) || p.at(INT_NUMBER));
-    assert!(p.nth(1) == T![:]);
-
-    let m = p.start();
-
-    if !p.eat(INT_NUMBER) {
-        name(p)
-    }
-
-    p.bump_any();
-    pattern(p);
-    m.complete(p, RECORD_FIELD_PAT);
-}
-
 // test placeholder_pat
 // fn main() { let _ = (); }
 fn placeholder_pat(p: &mut Parser) -> CompletedMarker {
diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 99c6b7219..7fca5661e 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -18,8 +18,8 @@ use crate::{
 pub use self::{
     expr_extensions::{ArrayExprKind, BinOp, ElseBranch, LiteralKind, PrefixOp, RangeOp},
     extensions::{
-        AttrKind, FieldKind, PathSegmentKind, SelfParamKind, SlicePatComponents, StructKind,
-        TypeBoundKind, VisibilityKind,
+        AttrKind, FieldKind, NameOrNameRef, PathSegmentKind, SelfParamKind, SlicePatComponents,
+        StructKind, TypeBoundKind, VisibilityKind,
     },
     generated::{nodes::*, tokens::*},
     tokens::*,
diff --git a/crates/ra_syntax/src/ast/extensions.rs b/crates/ra_syntax/src/ast/extensions.rs
index 63e272fbf..f2ea5088e 100644
--- a/crates/ra_syntax/src/ast/extensions.rs
+++ b/crates/ra_syntax/src/ast/extensions.rs
@@ -1,6 +1,8 @@
 //! Various extension methods to ast Nodes, which are hard to code-generate.
 //! Extensions for various expressions live in a sibling `expr_extensions` module.
 
+use std::fmt;
+
 use itertools::Itertools;
 use ra_parser::SyntaxKind;
 
@@ -217,6 +219,34 @@ impl ast::RecordField {
     }
 }
 
+pub enum NameOrNameRef {
+    Name(ast::Name),
+    NameRef(ast::NameRef),
+}
+
+impl fmt::Display for NameOrNameRef {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            NameOrNameRef::Name(it) => fmt::Display::fmt(it, f),
+            NameOrNameRef::NameRef(it) => fmt::Display::fmt(it, f),
+        }
+    }
+}
+
+impl ast::RecordFieldPat {
+    /// Deals with field init shorthand
+    pub fn field_name(&self) -> Option<NameOrNameRef> {
+        if let Some(name_ref) = self.name_ref() {
+            return Some(NameOrNameRef::NameRef(name_ref));
+        }
+        if let Some(ast::Pat::BindPat(pat)) = self.pat() {
+            let name = pat.name()?;
+            return Some(NameOrNameRef::Name(name));
+        }
+        None
+    }
+}
+
 impl ast::EnumVariant {
     pub fn parent_enum(&self) -> ast::EnumDef {
         self.syntax()
diff --git a/crates/ra_syntax/src/ast/generated/nodes.rs b/crates/ra_syntax/src/ast/generated/nodes.rs
index f1098755b..188f0df96 100644
--- a/crates/ra_syntax/src/ast/generated/nodes.rs
+++ b/crates/ra_syntax/src/ast/generated/nodes.rs
@@ -1806,8 +1806,8 @@ impl AstNode for RecordFieldPat {
     fn syntax(&self) -> &SyntaxNode { &self.syntax }
 }
 impl ast::AttrsOwner for RecordFieldPat {}
-impl ast::NameOwner for RecordFieldPat {}
 impl RecordFieldPat {
+    pub fn name_ref(&self) -> Option<NameRef> { support::child(&self.syntax) }
     pub fn colon_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![:]) }
     pub fn pat(&self) -> Option<Pat> { support::child(&self.syntax) }
 }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0102_record_field_pat_list.rast b/crates/ra_syntax/test_data/parser/inline/ok/0102_record_field_pat_list.rast
index c2614543c..fcd099de9 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0102_record_field_pat_list.rast
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0102_record_field_pat_list.rast
@@ -44,18 +44,20 @@ SOURCE_FILE@[0; 119)
             RECORD_FIELD_PAT_LIST@[40; 56)
               L_CURLY@[40; 41) "{"
               WHITESPACE@[41; 42) " "
-              BIND_PAT@[42; 43)
-                NAME@[42; 43)
-                  IDENT@[42; 43) "f"
+              RECORD_FIELD_PAT@[42; 43)
+                BIND_PAT@[42; 43)
+                  NAME@[42; 43)
+                    IDENT@[42; 43) "f"
               COMMA@[43; 44) ","
               WHITESPACE@[44; 45) " "
-              BIND_PAT@[45; 54)
-                REF_KW@[45; 48) "ref"
-                WHITESPACE@[48; 49) " "
-                MUT_KW@[49; 52) "mut"
-                WHITESPACE@[52; 53) " "
-                NAME@[53; 54)
-                  IDENT@[53; 54) "g"
+              RECORD_FIELD_PAT@[45; 54)
+                BIND_PAT@[45; 54)
+                  REF_KW@[45; 48) "ref"
+                  WHITESPACE@[48; 49) " "
+                  MUT_KW@[49; 52) "mut"
+                  WHITESPACE@[52; 53) " "
+                  NAME@[53; 54)
+                    IDENT@[53; 54) "g"
               WHITESPACE@[54; 55) " "
               R_CURLY@[55; 56) "}"
           WHITESPACE@[56; 57) " "
@@ -79,7 +81,7 @@ SOURCE_FILE@[0; 119)
               L_CURLY@[73; 74) "{"
               WHITESPACE@[74; 75) " "
               RECORD_FIELD_PAT@[75; 79)
-                NAME@[75; 76)
+                NAME_REF@[75; 76)
                   IDENT@[75; 76) "h"
                 COLON@[76; 77) ":"
                 WHITESPACE@[77; 78) " "
@@ -110,7 +112,7 @@ SOURCE_FILE@[0; 119)
               L_CURLY@[101; 102) "{"
               WHITESPACE@[102; 103) " "
               RECORD_FIELD_PAT@[103; 107)
-                NAME@[103; 104)
+                NAME_REF@[103; 104)
                   IDENT@[103; 104) "h"
                 COLON@[104; 105) ":"
                 WHITESPACE@[105; 106) " "
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0143_box_pat.rast b/crates/ra_syntax/test_data/parser/inline/ok/0143_box_pat.rast
index f75673070..1d245f8f3 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0143_box_pat.rast
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0143_box_pat.rast
@@ -44,16 +44,17 @@ SOURCE_FILE@[0; 118)
               RECORD_FIELD_PAT_LIST@[50; 81)
                 L_CURLY@[50; 51) "{"
                 WHITESPACE@[51; 52) " "
-                BOX_PAT@[52; 57)
-                  BOX_KW@[52; 55) "box"
-                  WHITESPACE@[55; 56) " "
-                  BIND_PAT@[56; 57)
-                    NAME@[56; 57)
-                      IDENT@[56; 57) "i"
+                RECORD_FIELD_PAT@[52; 57)
+                  BOX_PAT@[52; 57)
+                    BOX_KW@[52; 55) "box"
+                    WHITESPACE@[55; 56) " "
+                    BIND_PAT@[56; 57)
+                      NAME@[56; 57)
+                        IDENT@[56; 57) "i"
                 COMMA@[57; 58) ","
                 WHITESPACE@[58; 59) " "
                 RECORD_FIELD_PAT@[59; 79)
-                  NAME@[59; 60)
+                  NAME_REF@[59; 60)
                     IDENT@[59; 60) "j"
                   COLON@[60; 61) ":"
                   WHITESPACE@[61; 62) " "
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0145_record_field_pat.rast b/crates/ra_syntax/test_data/parser/inline/ok/0145_record_field_pat.rast
index 0d786f597..cac2ffdcf 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0145_record_field_pat.rast
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0145_record_field_pat.rast
@@ -25,7 +25,8 @@ SOURCE_FILE@[0; 63)
               L_CURLY@[21; 22) "{"
               WHITESPACE@[22; 23) " "
               RECORD_FIELD_PAT@[23; 27)
-                INT_NUMBER@[23; 24) "0"
+                NAME_REF@[23; 24)
+                  INT_NUMBER@[23; 24) "0"
                 COLON@[24; 25) ":"
                 WHITESPACE@[25; 26) " "
                 LITERAL_PAT@[26; 27)
@@ -54,7 +55,7 @@ SOURCE_FILE@[0; 63)
               L_CURLY@[46; 47) "{"
               WHITESPACE@[47; 48) " "
               RECORD_FIELD_PAT@[48; 52)
-                NAME@[48; 49)
+                NAME_REF@[48; 49)
                   IDENT@[48; 49) "x"
                 COLON@[49; 50) ":"
                 WHITESPACE@[50; 51) " "
diff --git a/crates/ra_syntax/test_data/parser/ok/0063_trait_fn_patterns.rast b/crates/ra_syntax/test_data/parser/ok/0063_trait_fn_patterns.rast
index 9b5954ebd..d0623ba90 100644
--- a/crates/ra_syntax/test_data/parser/ok/0063_trait_fn_patterns.rast
+++ b/crates/ra_syntax/test_data/parser/ok/0063_trait_fn_patterns.rast
@@ -68,14 +68,16 @@ SOURCE_FILE@[0; 170)
               RECORD_FIELD_PAT_LIST@[59; 67)
                 L_CURLY@[59; 60) "{"
                 WHITESPACE@[60; 61) " "
-                BIND_PAT@[61; 62)
-                  NAME@[61; 62)
-                    IDENT@[61; 62) "a"
+                RECORD_FIELD_PAT@[61; 62)
+                  BIND_PAT@[61; 62)
+                    NAME@[61; 62)
+                      IDENT@[61; 62) "a"
                 COMMA@[62; 63) ","
                 WHITESPACE@[63; 64) " "
-                BIND_PAT@[64; 65)
-                  NAME@[64; 65)
-                    IDENT@[64; 65) "b"
+                RECORD_FIELD_PAT@[64; 65)
+                  BIND_PAT@[64; 65)
+                    NAME@[64; 65)
+                      IDENT@[64; 65) "b"
                 WHITESPACE@[65; 66) " "
                 R_CURLY@[66; 67) "}"
             COLON@[67; 68) ":"
diff --git a/crates/ra_syntax/test_data/parser/ok/0064_impl_fn_params.rast b/crates/ra_syntax/test_data/parser/ok/0064_impl_fn_params.rast
index b30030de3..5e96b695b 100644
--- a/crates/ra_syntax/test_data/parser/ok/0064_impl_fn_params.rast
+++ b/crates/ra_syntax/test_data/parser/ok/0064_impl_fn_params.rast
@@ -71,14 +71,16 @@ SOURCE_FILE@[0; 137)
               RECORD_FIELD_PAT_LIST@[58; 66)
                 L_CURLY@[58; 59) "{"
                 WHITESPACE@[59; 60) " "
-                BIND_PAT@[60; 61)
-                  NAME@[60; 61)
-                    IDENT@[60; 61) "a"
+                RECORD_FIELD_PAT@[60; 61)
+                  BIND_PAT@[60; 61)
+                    NAME@[60; 61)
+                      IDENT@[60; 61) "a"
                 COMMA@[61; 62) ","
                 WHITESPACE@[62; 63) " "
-                BIND_PAT@[63; 64)
-                  NAME@[63; 64)
-                    IDENT@[63; 64) "b"
+                RECORD_FIELD_PAT@[63; 64)
+                  BIND_PAT@[63; 64)
+                    NAME@[63; 64)
+                      IDENT@[63; 64) "b"
                 WHITESPACE@[64; 65) " "
                 R_CURLY@[65; 66) "}"
             COLON@[66; 67) ":"