3552

Stop requiring jump instructions to explicitly provide a ':label' type
for jump targets.

This has been a source of repeated confusion for my students:
  a) They'd add the ':label' to the label definition rather than the
  jump target (label use)
  b) They'd spend time thinking about whether the initial '+' prefix was
  part of the label name.

In the process I cleaned up a couple of things:

  - the space of names is more cleanly partitioned into labels and
    non-labels (clarifying that '_' and '-' are non-label prefixes)
  - you can't use label names as regular variables anymore
  - you can infer the type of a label just from its name

1 files changed, 1 insertions, 1 deletions

diff --git a/chessboard.mu b/chessboard.mu
index 2030d910..f78027ab 100644
--- a/chessboard.mu
+++ b/chessboard.mu
@@ -90,7 +90,7 @@ def chessboard screen:&:screen, console:&:console -> screen:&:screen, console:&:
       cursor-to-next-line screen
       screen <- print screen, [move: ]
       m:&:move, quit:bool, error:bool <- read-move buffered-stdin-in, screen
-      break-if quit, +quit:label
+      break-if quit, +quit
       buffered-stdin-in <- clear buffered-stdin-in  # cleanup after error. todo: test this?
       loop-if error
     }