Merge #3169

3169: Show record field names in Enum completion r=flodiebold a=adamrk

Adresses https://github.com/rust-analyzer/rust-analyzer/issues/2947.
Previously the details shown when autocompleting an Enum variant would look like the variant was a tuple even if it was a record:
![2020-02-16-15:59:32_crop](https://user-images.githubusercontent.com/16367467/74607233-64f21980-50d7-11ea-99db-e973e29c71d7.png)

This change will show the names of the fields for a record and use curly braces instead of parentheses:
![2020-02-16-15:33:00_crop](https://user-images.githubusercontent.com/16367467/74607251-8ce17d00-50d7-11ea-9d4d-38d198a4aec0.png)

This required exposing the type `adt::StructKind` from `ra_hir` and adding a function 
```
kind(self, db: &impl HirDatabase) -> StructKind
```
in the `impl` of `EnumVariant`. 

There was also a previously existing function `is_unit(self, db: &impl HirDatabase) -> bool` for `EnumVariant` which I removed because it seemed redundant after adding `kind`.

Co-authored-by: adamrk <[email protected]>

1 files changed, 5 insertions, 4 deletions

diff --git a/crates/ra_hir_def/src/adt.rs b/crates/ra_hir_def/src/adt.rs
index aac5f3e15..985f409e8 100644
--- a/crates/ra_hir_def/src/adt.rs
+++ b/crates/ra_hir_def/src/adt.rs
@@ -140,10 +140,11 @@ impl VariantData {
         self.fields().iter().find_map(|(id, data)| if &data.name == name { Some(id) } else { None })
     }
 
-    pub fn is_unit(&self) -> bool {
+    pub fn kind(&self) -> StructKind {
         match self {
-            VariantData::Unit => true,
-            _ => false,
+            VariantData::Record(_) => StructKind::Record,
+            VariantData::Tuple(_) => StructKind::Tuple,
+            VariantData::Unit => StructKind::Unit,
         }
     }
 }
@@ -173,7 +174,7 @@ impl HasChildSource for VariantId {
     }
 }
 
-enum StructKind {
+pub enum StructKind {
     Tuple,
     Record,
     Unit,