Fix optional integer promotion

2 files changed, 28 insertions, 6 deletions

diff --git a/compile.c b/compile.c
index f5ed809d..8da5eba4 100644
--- a/compile.c
+++ b/compile.c
@@ -44,6 +44,7 @@ CORD promote_to_optional(type_t *t, CORD code)
         return code;
     }
 }
+
 static bool promote(env_t *env, CORD *code, type_t *actual, type_t *needed)
 {
     if (type_eq(actual, needed))
@@ -52,6 +53,12 @@ static bool promote(env_t *env, CORD *code, type_t *actual, type_t *needed)
     if (!can_promote(actual, needed))
         return false;
 
+    // Optional promotion:
+    if (needed->tag == OptionalType && type_eq(actual, Match(needed, OptionalType)->type)) {
+        *code = promote_to_optional(actual, *code);
+        return true;
+    }
+
     if (actual->tag == IntType && needed->tag == BigIntType) {
         *code = CORD_all("I(", *code, ")");
         return true;
@@ -81,12 +88,6 @@ static bool promote(env_t *env, CORD *code, type_t *actual, type_t *needed)
         return promote(env, code, Match(actual, PointerType)->pointed, needed);
     }
 
-    // Optional promotion:
-    if (needed->tag == OptionalType && type_eq(actual, Match(needed, OptionalType)->type)) {
-        *code = promote_to_optional(actual, *code);
-        return true;
-    }
-
     // Stack ref promotion:
     if (actual->tag == PointerType && needed->tag == PointerType)
         return true;
diff --git a/test/optionals.tm b/test/optionals.tm
index e5ee9bcc..e2cdf9a6 100644
--- a/test/optionals.tm
+++ b/test/optionals.tm
@@ -19,6 +19,12 @@ func maybe_int(should_i:Bool)->Int?:
     else:
         return !Int
 
+func maybe_int64(should_i:Bool)->Int64?:
+    if should_i:
+        return 123_i64
+    else:
+        return !Int64
+
 func maybe_array(should_i:Bool)->[Int]?:
     if should_i:
         return [10, 20, 30]
@@ -93,6 +99,21 @@ func main():
 
     do:
         !! ...
+        !! Int64s:
+        >> yep := maybe_int64(yes)
+        = 123_i64?
+        >> nope := maybe_int64(no)
+        = !Int64
+        >> if yep:
+            >> yep
+            = 123_i64
+        else: fail("Falsey: $yep")
+        >> if nope:
+            fail("Truthy: $nope")
+        else: !! Falsey: $nope
+
+    do:
+        !! ...
         !! Arrays:
         >> yep := maybe_array(yes)
         = [10, 20, 30]?