Use HIR Expr for type inference

Now we can reuse the type inference inside a function when typing whitespace
etc. :)

2 files changed, 17 insertions, 6 deletions

diff --git a/crates/ra_analysis/src/completion/complete_dot.rs b/crates/ra_analysis/src/completion/complete_dot.rs
index 031d8b98f..ef3f4271b 100644
--- a/crates/ra_analysis/src/completion/complete_dot.rs
+++ b/crates/ra_analysis/src/completion/complete_dot.rs
@@ -1,3 +1,4 @@
+use ra_db::LocalSyntaxPtr;
 use ra_syntax::ast::AstNode;
 use hir::{Ty, Def};
 
@@ -11,11 +12,14 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) -> Ca
         _ => return Ok(()),
     };
     let infer_result = function.infer(ctx.db)?;
-    let receiver_ty = if let Some(ty) = infer_result.type_of_node(receiver.syntax()) {
-        ty
-    } else {
-        return Ok(());
-    };
+    let syntax_mapping = function.body_syntax_mapping(ctx.db)?;
+    let expr =
+        if let Some(expr) = syntax_mapping.syntax_expr(LocalSyntaxPtr::new(receiver.syntax())) {
+            expr
+        } else {
+            return Ok(());
+        };
+    let receiver_ty = infer_result[expr].clone();
     if !ctx.is_method_call {
         complete_fields(acc, ctx, receiver_ty)?;
     }
diff --git a/crates/ra_analysis/src/hover.rs b/crates/ra_analysis/src/hover.rs
index ba1fb9beb..067e5c12d 100644
--- a/crates/ra_analysis/src/hover.rs
+++ b/crates/ra_analysis/src/hover.rs
@@ -64,7 +64,14 @@ pub(crate) fn type_of(db: &RootDatabase, frange: FileRange) -> Cancelable<Option
         parent_fn
     )?);
     let infer = function.infer(db)?;
-    Ok(infer.type_of_node(node).map(|t| t.to_string()))
+    let syntax_mapping = function.body_syntax_mapping(db)?;
+    if let Some(expr) = syntax_mapping.node_expr(node) {
+        Ok(Some(infer[expr].to_string()))
+    } else if let Some(pat) = syntax_mapping.node_pat(node) {
+        Ok(Some(infer[pat].to_string()))
+    } else {
+        Ok(None)
+    }
 }
 
 // FIXME: this should not really use navigation target. Rather, approximatelly