snapshot: attempt at modifying a function name

It turns out there's another problem, and it predates the ability to create
new definitions:

  ctrl-s triggers a call to `evaluate`, which inserts a new definition
  into globals. which has a null gap buffer.

All this happens long before the new code in this commit, resulting in a
null gap buffer by the time we get to word-at-cursor.

Which in turn happens because we perform a raw `evaluate`, which doesn't
update the gap buffer like `run` does (using `maybe-stash-gap-buffer-to-global`).

And arguably `evaluate` shouldn't mess with the gap buffer. Gap buffers
are a UI concern.

The hardest version of this immediate scenario: It's unclear how to guarantee
that every definition have a gap buffer, when two definitions may share
one (closures sharing a lexical environment).

New plan:
  - improve the logic for detecting definitions. Looking at the outermost
    layer isn't enough. And a single expression can create multiple definitions.
  - extract a helper to attach a single gap buffer to multiple definitions.
  - have the UI detect conflicts in gap buffers and prompt the user for
    a decision if a different gap buffer already exists for a definition.

1 files changed, 14 insertions, 13 deletions

diff --git a/mu-init.subx b/mu-init.subx
index 8fcf84e3..321dd66a 100644
--- a/mu-init.subx
+++ b/mu-init.subx
@@ -14,19 +14,20 @@ Entry:
   bd/copy-to-ebp 0/imm32
   #
 #?   (main 0 0 Primary-bus-secondary-drive)
-  # always first run tests
-  (run-tests)
-  (num-test-failures)  # => eax
-  # call main if tests all passed
-  {
-    3d/compare-eax-and 0/imm32
-    75/jump-if-!= break/disp8
-    c7 0/subop/copy *Running-tests? 0/imm32/false
-    (clear-real-screen)
-    c7 0/subop/copy *Real-screen-cursor-x 0/imm32
-    c7 0/subop/copy *Real-screen-cursor-y 0/imm32
-    (main 0 0 Primary-bus-secondary-drive)
-  }
+  (test-create-function-with-new-name)
+#?   # always first run tests
+#?   (run-tests)
+#?   (num-test-failures)  # => eax
+#?   # call main if tests all passed
+#?   {
+#?     3d/compare-eax-and 0/imm32
+#?     75/jump-if-!= break/disp8
+#?     c7 0/subop/copy *Running-tests? 0/imm32/false
+#?     (clear-real-screen)
+#?     c7 0/subop/copy *Real-screen-cursor-x 0/imm32
+#?     c7 0/subop/copy *Real-screen-cursor-y 0/imm32
+#?     (main 0 0 Primary-bus-secondary-drive)
+#?   }
 
   # hang indefinitely
   {