DBC now works and has a test.

meson.build

@@ -29,6 +29,7 @@ subdir('scratchpad')
 
 executable('escape_turings_tarpit',
   ['game_engine.cpp',
+    'dbc.cpp',
     'gui.cpp',
     'watcher.cpp',
     'builder.cpp',
@@ -37,9 +38,11 @@ executable('escape_turings_tarpit',
   dependencies: dependencies)
 
 runtests = executable('runtests', [
+  'dbc.cpp',
   'game_engine.cpp',
   'tests/game_engine.cpp',
   'tests/fsm.cpp',
+  'tests/dbc.cpp',
   ],
   dependencies: dependencies + [catch2])