support bytes_unpack operator in pascaligo + tests

src/passes/operators/operators.ml

@@ -92,6 +92,7 @@ module Simplify = struct
       | "bytes_concat"    -> ok C_CONCAT
       | "bytes_slice"     -> ok C_SLICE
       | "bytes_pack"      -> ok C_BYTES_PACK
+      | "bytes_unpack"    -> ok C_BYTES_UNPACK
       | "set_empty"       -> ok C_SET_EMPTY
       | "set_mem"         -> ok C_SET_MEM
       | "set_add"         -> ok C_SET_ADD

src/test/contracts/bytes_unpack.ligo

@@ -0,0 +1,11 @@
+function id_string (const p : string) : option(string) is block {
+  const packed : bytes = bytes_pack(p) ;
+} with (bytes_unpack(packed): option(string))
+
+function id_int (const p : int) : option(int) is block {
+  const packed : bytes = bytes_pack(p) ;
+} with (bytes_unpack(packed): option(int))
+
+function id_address (const p : address) : option(address) is block {
+  const packed : bytes = bytes_pack(p) ;
+} with (bytes_unpack(packed): option(address))

src/test/integration_tests.ml

@@ -1812,7 +1812,18 @@ let let_in_multi_bind () : unit result =
       (e_string "mynameisbob")
   in ok ()
 
+let bytes_unpack () : unit result =
+  let%bind program = type_file "./contracts/bytes_unpack.ligo" in
+  let%bind () = expect_eq program "id_string" (e_string "teststring") (e_some (e_string "teststring")) in
+  let%bind () = expect_eq program "id_int" (e_int 42) (e_some (e_int 42)) in
+  let open Proto_alpha_utils.Memory_proto_alpha in
+  let addr = Protocol.Alpha_context.Contract.to_b58check @@
+      (List.nth dummy_environment.identities 0).implicit_contract in
+  let%bind () = expect_eq program "id_address" (e_address addr) (e_some (e_address addr)) in
+  ok ()
+
 let main = test_suite "Integration (End to End)" [
+    test "bytes unpack" bytes_unpack ;
     test "key hash" key_hash ;
     test "chain id" chain_id ;
     test "type alias" type_alias ;