implement initial type inference for index expressions

1 files changed, 13 insertions, 1 deletions

diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index 5430a0c9f..a16561d11 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -245,6 +245,10 @@ pub enum Expr {
         rhs: ExprId,
         op: Option<BinaryOp>,
     },
+    Index {
+        base: ExprId,
+        index: ExprId,
+    },
     Lambda {
         args: Vec<PatId>,
         arg_types: Vec<Option<TypeRef>>,
@@ -399,6 +403,10 @@ impl Expr {
                 f(*lhs);
                 f(*rhs);
             }
+            Expr::Index { base, index } => {
+                f(*base);
+                f(*index);
+            }
             Expr::Field { expr, .. }
             | Expr::Await { expr }
             | Expr::Try { expr }
@@ -887,10 +895,14 @@ where
                 };
                 self.alloc_expr(Expr::Literal(lit), syntax_ptr)
             }
+            ast::ExprKind::IndexExpr(e) => {
+                let base = self.collect_expr_opt(e.base());
+                let index = self.collect_expr_opt(e.index());
+                self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
+            }
 
             // FIXME implement HIR for these:
             ast::ExprKind::Label(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
-            ast::ExprKind::IndexExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
             ast::ExprKind::RangeExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
             ast::ExprKind::MacroCall(e) => {
                 let ast_id = self