Currently a condition can only be a regexp or a major-mode symbol but
there's no real reason to not allow any predicate as a condition.
* doc/misc/autotype.texi: Document the new condition type in
'auto-insert-alist'.
* etc/NEWS: Announce the new condition type in 'auto-insert-alist'.
* lisp/autoinsert.el (auto-insert-alist): Add the new condition type to
the variable documentation.
(auto-insert): Change the way the condition is matched to allow for
custom predicates.
* test/lisp/autoinsert-tests.el
(autoinsert-tests-auto-insert-lambda/-nil): Add two tests for
lambdas (nil and t cases)
(autoinsert-tests-auto-insert-predicate/-nil): Add two tests for named
predicates (nil and t cases) (Bug#79178)
bd1362b686