Neovim crash when writing set map

[ahelwer]

Neovim 0.7.2 will crash when writing the following:

set_map == {x + y + z : x, y,

It does not crash if the closing curly brace is typed before typing the generator. Possibly something in the external scanner? Should check whether this also happens in the playground, whether it is unicode-related, etc.

[ahelwer]

It will also crash when writing:

---- MODULE Test ----
func_literal ≜ ∧ [x
====

but not:

---- MODULE Test ----
func_literal == [x
====

lending credence to this being an external scanner issue. Again typing the closing square bracket stops this from happening.

[ahelwer]

As of neovim 0.8.2 this no longer seems to occur.

[ahelwer]

Reopening, occurs with following input even when parsing static file:

---- MODULE Test ----
op == [ ]
THEOREM TRUE
<*> 1
<*> QED
====

[ahelwer]

Another one causing a crash:

---- MODULE Test ----
THEOREM A
  <1> QED BY B
  <1> QED
=====================

Seems best practice to harden the external scanner by checking whether we are in a jlist/proof/pcal block by looking at the relevant stacks, rather than relying on the parser to give us accurate expected symbol information.