571 - screen primitives take an explicit terminal

This will let me swap in a fake in tests.

Still hacky, though. I'm sure I'm not managing the parameter right in
the chessboard app.

And then there's the question of whether it should also appear as an
output operand.

But it's a start. And using nil to mean 'real' is a reasonable
convention.

If I ever need to handle multiple screens perhaps we'll have to switch
to 1:literal/terminal and 2:literal/terminal, etc. But those are equally
easy to guard on.

1 files changed, 2 insertions, 2 deletions

diff --git a/fork.mu b/fork.mu
index ba19e3af..edd8eb8d 100644
--- a/fork.mu
+++ b/fork.mu
@@ -3,7 +3,7 @@
   (default-space:space-address <- new space:literal 2:literal)
   (x:integer <- copy 34:literal)
   { begin
-    (print-primitive x:integer)
+    (print-primitive nil:literal/terminal x:integer)
     (loop)
   }
 ])
@@ -12,7 +12,7 @@
   (default-space:space-address <- new space:literal 2:literal)
   (y:integer <- copy 35:literal)
   { begin
-    (print-primitive y:integer)
+    (print-primitive nil:literal/terminal y:integer)
     (loop)
   }
 ])