test: heterogeneous + and *

tests/lean/run/hmul2.lean

@@ -0,0 +1,56 @@
+class HMul (α : Type u) (β : Type v) (γ : outParam (Type w)) where
+  hmul : α → β → γ
+
+class HAdd (α : Type u) (β : Type v) (γ : outParam (Type w)) where
+  hadd : α → β → γ
+
+@[defaultInstance 1]
+instance [Mul α] : HMul α α α where
+  hmul a b := a * b
+
+@[defaultInstance 1]
+instance [Add α] : HAdd α α α where
+  hadd a b := a + b
+
+instance [Mul α] : HMul α (Array α) (Array α) where
+  hmul a as := as.map (a * .)
+
+infix:70 [1] "*" => HMul.hmul
+
+infix:65 [1] "+" => HAdd.hadd
+
+#check fun x => x * 2
+#check fun y : Int => let  x := 1; x * y
+#check fun y : Int => let* x := 1; x * y
+
+instance : HMul Nat Int Int where
+  hmul a b := Int.mul a b
+
+instance : HMul Int Nat Int where
+  hmul a b := Int.mul a b
+
+instance : HAdd Nat Int Int where
+  hadd a b := Int.add a b
+
+instance : HAdd Int Nat Int where
+  hadd a b := Int.add a b
+
+def f1 (n : Nat) (i : Int) :=
+  i * n
+
+def f2 (n : Nat) (i : Int) :=
+  n * i
+
+def f3 (n : Nat) (i : Int) :=
+  n * (n * (n * (n * i)))
+
+def f4 (n : Nat) (i : Int) :=
+  n + (n + (n * (n * i)))
+
+def f5 (n : Nat) (i : Int) :=
+  n + (n + (n * (i, i).1))
+
+#eval (2:Nat) * #[3, 4, 5]
+
+def f6 (n : Nat) (i : Int) :=
+  n + n * (2:Nat) * i