Why does org see this source block as having "unbalanced parentheses"?

Question

Here is a terse snippet with which you can recreate the issue, I hope:

#+begin_src sh
for x in $(for y in $(cmdA '"'); do cmdB $y; done); do cmdC $x; done
#+end_src

Here if I try to operate with respect to parenthetical operations (e.g. delete surrounding), or if I simply try to fold/close-all, I get forward-sexp: Scan error: "Unbalanced parentheses", nnnnn, mmmmm. If I remove '"' this goes away, but this is valid sh, so I'm unclear why this is.

My version information is:

GNU Emacs 28.1 (build 1, x86_64-apple-darwin21.4.0, NS appkit-2113.40 Version 12.3.1 (Build 21E258)) of 2022-04-21
Doom core     v3.0.0-dev       HEAD -> master f51a2cdd3 2022-04-18 18:14:16 +0200
Doom modules  v22.04.0-dev     HEAD -> master f51a2cdd3 2022-04-18 18:14:16 +0200

If you have any ideas or if this is expected behavior, let me know.

Answer 1

The problem is that the buffer's major mode is Org mode, not sh-mode. The syntax rules for Org mode do not know about constructs like '"' and the unmatched " causes havoc. It would be possible perhaps to switch major mode depending on the context[1], but that has been deemed much too complicated a way to deal with a relatively minor problem: my recollection is that it has been brought up on the mailing list and the advice has been: "You'll have to live with it".

You can do C-c ' on the source block and get a buffer in sh-mode for this block, where delimiter scanning works as you would expect.

[1] There is a package called polymode but I'm unsure whether it provides context-dependent major modes in the same buffer or whether it allows multiple major modes to coexist somehow. I have the impression that it is somewhat fragile, but I have never used it, so treat this as hearsay plus recollections from my very imperfect memory.