Optionals for threads

builtins/optionals.c

@@ -3,6 +3,7 @@
 #include "bool.h"
 #include "datatypes.h"
 #include "integers.h"
+#include "thread.h"
 #include "text.h"
 #include "util.h"
 
@@ -29,6 +30,8 @@ static inline bool is_null(const void *obj, const TypeInfo *non_optional_type)
         return ((OptionalInt16_t*)obj)->is_null;
     else if (non_optional_type == &Int8$info)
         return ((OptionalInt8_t*)obj)->is_null;
+    else if (non_optional_type == &Thread)
+        return *(pthread_t**)obj == NULL;
 
     switch (non_optional_type->tag) {
         case ChannelInfo: return *(channel_t**)obj == NULL;

compile.c

@@ -27,7 +27,9 @@ static CORD promote_to_optional(type_t *t, CORD code);
 
 CORD promote_to_optional(type_t *t, CORD code)
 {
-    if (t->tag == IntType) {
+    if (t == THREAD_TYPE) {
+        return code;
+    } else if (t->tag == IntType) {
         switch (Match(t, IntType)->bits) {
         case TYPE_IBITS8: return CORD_all("((OptionalInt8_t){.i=", code, "})");
         case TYPE_IBITS16: return CORD_all("((OptionalInt16_t){.i=", code, "})");

test/optionals.tm

@@ -61,6 +61,12 @@ func maybe_channel(should_i:Bool)->|Int|?:
     else:
         return !|Int|
 
+func maybe_thread(should_i:Bool)->Thread?:
+    if should_i:
+        return Thread.new(func(): pass)
+    else:
+        return !Thread
+
 func main():
     >> 5?
     = 5? : Int?
@@ -200,6 +206,19 @@ func main():
             fail("Truthy: $nope")
         else: !! Falsey: $nope
 
+    do:
+        !! ...
+        !! Threads:
+        >> yep := maybe_thread(yes)
+        # No "=" test here because threads use addresses in the text version
+        >> nope := maybe_thread(no)
+        = !Thread
+        >> if yep: >> yep
+        else: fail("Falsey: $yep")
+        >> if nope:
+            fail("Truthy: $nope")
+        else: !! Falsey: $nope
+
     if yep := maybe_int(yes):
         >> yep
         = 123 : Int