3 files changed, 45 insertions, 71 deletions

diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index 675df4a22..cca59538a 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -1265,9 +1265,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Expr::BinaryOp { lhs, rhs, op } => match op {
                 Some(op) => {
                     let lhs_expectation = match op {
-                        BinaryOp::BooleanAnd | BinaryOp::BooleanOr => {
-                            Expectation::has_type(Ty::simple(TypeCtor::Bool))
-                        }
+                        BinaryOp::LogicOp(..) => Expectation::has_type(Ty::simple(TypeCtor::Bool)),
                         _ => Expectation::none(),
                     };
                     let lhs_ty = self.infer_expr(*lhs, &lhs_expectation);
@@ -1281,6 +1279,12 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
                 _ => Ty::Unknown,
             },
+            Expr::Index { base, index } => {
+                let _base_ty = self.infer_expr(*base, &Expectation::none());
+                let _index_ty = self.infer_expr(*index, &Expectation::none());
+                // FIXME: use `std::ops::Index::Output` to figure out the real return type
+                Ty::Unknown
+            }
             Expr::Tuple { exprs } => {
                 let mut ty_vec = Vec::with_capacity(exprs.len());
                 for arg in exprs.iter() {
diff --git a/crates/ra_hir/src/ty/op.rs b/crates/ra_hir/src/ty/op.rs
index 9ba868298..1b30a5b9b 100644
--- a/crates/ra_hir/src/ty/op.rs
+++ b/crates/ra_hir/src/ty/op.rs
@@ -1,37 +1,14 @@
 use super::{InferTy, Ty, TypeCtor};
-use crate::{expr::BinaryOp, ty::ApplicationTy};
+use crate::{
+    expr::{BinaryOp, CmpOp},
+    ty::ApplicationTy,
+};
 
 pub(super) fn binary_op_return_ty(op: BinaryOp, rhs_ty: Ty) -> Ty {
     match op {
-        BinaryOp::BooleanOr
-        | BinaryOp::BooleanAnd
-        | BinaryOp::EqualityTest
-        | BinaryOp::NegatedEqualityTest
-        | BinaryOp::LesserEqualTest
-        | BinaryOp::GreaterEqualTest
-        | BinaryOp::LesserTest
-        | BinaryOp::GreaterTest => Ty::simple(TypeCtor::Bool),
-        BinaryOp::Assignment
-        | BinaryOp::AddAssign
-        | BinaryOp::SubAssign
-        | BinaryOp::DivAssign
-        | BinaryOp::MulAssign
-        | BinaryOp::RemAssign
-        | BinaryOp::ShrAssign
-        | BinaryOp::ShlAssign
-        | BinaryOp::BitAndAssign
-        | BinaryOp::BitOrAssign
-        | BinaryOp::BitXorAssign => Ty::unit(),
-        BinaryOp::Addition
-        | BinaryOp::Subtraction
-        | BinaryOp::Multiplication
-        | BinaryOp::Division
-        | BinaryOp::Remainder
-        | BinaryOp::LeftShift
-        | BinaryOp::RightShift
-        | BinaryOp::BitwiseAnd
-        | BinaryOp::BitwiseOr
-        | BinaryOp::BitwiseXor => match rhs_ty {
+        BinaryOp::LogicOp(_) | BinaryOp::CmpOp(_) => Ty::simple(TypeCtor::Bool),
+        BinaryOp::Assignment { .. } => Ty::unit(),
+        BinaryOp::ArithOp(_) => match rhs_ty {
             Ty::Apply(ApplicationTy { ctor, .. }) => match ctor {
                 TypeCtor::Int(..) | TypeCtor::Float(..) => rhs_ty,
                 _ => Ty::Unknown,
@@ -39,49 +16,29 @@ pub(super) fn binary_op_return_ty(op: BinaryOp, rhs_ty: Ty) -> Ty {
             Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => rhs_ty,
             _ => Ty::Unknown,
         },
-        BinaryOp::RangeRightOpen | BinaryOp::RangeRightClosed => Ty::Unknown,
     }
 }
 
 pub(super) fn binary_op_rhs_expectation(op: BinaryOp, lhs_ty: Ty) -> Ty {
     match op {
-        BinaryOp::BooleanAnd | BinaryOp::BooleanOr => Ty::simple(TypeCtor::Bool),
-        BinaryOp::Assignment | BinaryOp::EqualityTest => match lhs_ty {
-            Ty::Apply(ApplicationTy { ctor, .. }) => match ctor {
-                TypeCtor::Int(..)
-                | TypeCtor::Float(..)
-                | TypeCtor::Str
-                | TypeCtor::Char
-                | TypeCtor::Bool => lhs_ty,
+        BinaryOp::LogicOp(..) => Ty::simple(TypeCtor::Bool),
+        BinaryOp::Assignment { op: None } | BinaryOp::CmpOp(CmpOp::Eq { negated: _ }) => {
+            match lhs_ty {
+                Ty::Apply(ApplicationTy { ctor, .. }) => match ctor {
+                    TypeCtor::Int(..)
+                    | TypeCtor::Float(..)
+                    | TypeCtor::Str
+                    | TypeCtor::Char
+                    | TypeCtor::Bool => lhs_ty,
+                    _ => Ty::Unknown,
+                },
+                Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => lhs_ty,
                 _ => Ty::Unknown,
-            },
-            Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => lhs_ty,
-            _ => Ty::Unknown,
-        },
-        BinaryOp::LesserEqualTest
-        | BinaryOp::GreaterEqualTest
-        | BinaryOp::LesserTest
-        | BinaryOp::GreaterTest
-        | BinaryOp::AddAssign
-        | BinaryOp::SubAssign
-        | BinaryOp::DivAssign
-        | BinaryOp::MulAssign
-        | BinaryOp::RemAssign
-        | BinaryOp::ShrAssign
-        | BinaryOp::ShlAssign
-        | BinaryOp::BitAndAssign
-        | BinaryOp::BitOrAssign
-        | BinaryOp::BitXorAssign
-        | BinaryOp::Addition
-        | BinaryOp::Subtraction
-        | BinaryOp::Multiplication
-        | BinaryOp::Division
-        | BinaryOp::Remainder
-        | BinaryOp::LeftShift
-        | BinaryOp::RightShift
-        | BinaryOp::BitwiseAnd
-        | BinaryOp::BitwiseOr
-        | BinaryOp::BitwiseXor => match lhs_ty {
+            }
+        }
+        BinaryOp::CmpOp(CmpOp::Ord { .. })
+        | BinaryOp::Assignment { op: Some(_) }
+        | BinaryOp::ArithOp(_) => match lhs_ty {
             Ty::Apply(ApplicationTy { ctor, .. }) => match ctor {
                 TypeCtor::Int(..) | TypeCtor::Float(..) => lhs_ty,
                 _ => Ty::Unknown,
@@ -89,6 +46,5 @@ pub(super) fn binary_op_rhs_expectation(op: BinaryOp, lhs_ty: Ty) -> Ty {
             Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => lhs_ty,
             _ => Ty::Unknown,
         },
-        _ => Ty::Unknown,
     }
 }
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index 28727bb18..6c2d857bc 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -2656,6 +2656,20 @@ fn test() -> u64 {
 }
 
 #[test]
+fn indexing_arrays() {
+    assert_snapshot_matches!(
+        infer("fn main() { &mut [9][2]; }"),
+        @r###"
+[10; 26) '{ &mut...[2]; }': ()
+[12; 23) '&mut [9][2]': &mut {unknown}
+[17; 20) '[9]': [i32;_]
+[17; 23) '[9][2]': {unknown}
+[18; 19) '9': i32
+[21; 22) '2': i32"###
+    )
+}
+
+#[test]
 fn infer_macros_expanded() {
     assert_snapshot_matches!(
         infer(r#"