fix: provide type to select instruction (#46)

* fix: provide type to select instruction

* Add test for select instruction

src/expression.ml

@@ -65,7 +65,9 @@ external unary : Module.t -> Op.t -> t -> t = "caml_binaryen_unary"
 
 external binary : Module.t -> Op.t -> t -> t -> t = "caml_binaryen_binary"
 
-external select : Module.t -> t -> t -> t -> t = "caml_binaryen_select"
+external select : Module.t -> t -> t -> t -> Type.t -> t = "caml_binaryen_select"
+let select wasm_mod cond tru fals =
+  select wasm_mod cond tru fals Type.auto
 (** Module, condition, true branch, false branch. *)
 
 external drop : Module.t -> t -> t = "caml_binaryen_drop"

test/test.expected

@@ -3,7 +3,11 @@
  (func $adder (param $0 i32) (param $1 i32) (result i32)
   (block $add (result i32)
    (i32.add
-    (local.get $0)
+    (select
+     (local.get $0)
+     (local.get $1)
+     (i32.const 1)
+    )
     (local.get $1)
    )
   )
@@ -13,7 +17,11 @@
  (type $i32_i32_=>_i32 (func (param i32 i32) (result i32)))
  (func $0 (param $0 i32) (param $1 i32) (result i32)
   (i32.add
-   (local.get $0)
+   (select
+    (local.get $0)
+    (local.get $1)
+    (i32.const 1)
+   )
    (local.get $1)
   )
  )

test/test.ml

@@ -12,7 +12,9 @@ let x = Expression.local_get wasm_mod 0 Type.int32
 
 let y = Expression.local_get wasm_mod 1 Type.int32
 
-let add = Expression.block wasm_mod ~return_type:Type.int32 "add" [Expression.binary wasm_mod Op.add_int32 x y]
+let select = Expression.select wasm_mod (Expression.const wasm_mod (Literal.int32 1l)) x y
+
+let add = Expression.block wasm_mod ~return_type:Type.int32 "add" [Expression.binary wasm_mod Op.add_int32 select y]
 
 (* Create the add function *)
 let adder = Function.add_function wasm_mod "adder" params results [||] add