fix(snippets): stop electric-pair from stranding ">" after "<"-key snippets

Most of the yasnippet keys start with "<" (<cj, <for, <main, ...), mirroring org-tempo. electric-pair-mode pairs "<" into "<>" wherever the mode's syntax table gives "<" paren syntax, which org and the pairing-enabled prog modes both do. So typing "<cj" lands as "<cj>", and expanding the "<cj" key strands the ">" after the snippet. The cj-comment block came out with a "#+end_src>" close fence, which breaks the cj-scan fence parser and made every respond-to-cj-comments pass hand-parse around it.

I set electric-pair-inhibit-predicate globally to inhibit the open angle bracket and defer to the default for every other character. That keeps the "<"-prefixed snippet convention intact across all 14 of them, at the cost of "<>" auto-pairing where it might otherwise be wanted (C++ templates). The snippet convention is universal, so it wins.

Surfaced from the smoke project, which kept hitting the malformed fence in its todo.org.

1 files changed, 16 insertions, 0 deletions

diff --git a/modules/prog-general.el b/modules/prog-general.el
index a4be7205..8b4dedda 100644
--- a/modules/prog-general.el
+++ b/modules/prog-general.el
@@ -298,6 +298,22 @@ This is what makes universal snippets like =<cj= work in any buffer."
   (yas-reload-all)
   (yas-global-mode 1))
 
+;; Most of the snippet keys start with "<" (=<cj=, =<for=, =<main=…), mirroring
+;; org-tempo.  But `electric-pair-mode' pairs "<" into "<>" wherever the mode's
+;; syntax table gives "<" paren syntax (org, and the prog modes that enable
+;; pairing), so typing "<cj" lands as "<cj>"; expanding the "<cj" key then
+;; strands the ">" after the snippet — the cj-comment fence comes out as
+;; "#+end_src>", which breaks the cj-scan fence parser.  Inhibit pairing for the
+;; open angle bracket globally; defer to the default for every other character.
+(defun cj/--electric-pair-inhibit-angle (char)
+  "Return non-nil to stop `electric-pair-mode' from pairing the angle CHAR.
+Inhibit the open angle bracket so \"<\"-prefixed yasnippet keys expand cleanly;
+defer to `electric-pair-default-inhibit' for any other CHAR."
+  (or (eq char ?<)
+      (electric-pair-default-inhibit char)))
+
+(setq electric-pair-inhibit-predicate #'cj/--electric-pair-inhibit-angle)
+
 ;; --------------------- Display Color On Color Declaration --------------------
 ;; display the actual color as highlight to color hex code