New tree-sitter toggle scheme

This version: central variable, everything controlled by
treesit-settings.  Major mode sets up tree-sitter/non-tree-sitter
in a conditional branch, based on the setting.

* lisp/treesit.el (treesit-settings): New option.
(treesit-defun-type-regexp): Change docstring.
(treesit-mode-supported)
(treesit-required-languages)
(treesit--local-variable-backup): Remove variables.
(treesit--backup-local-variable)
(treesit-mode)
(global-treesit-mode--turn-on)
(global-treesit-mode): Remove functions.
(treesit--setting-for-mode): New function.
(treesit-ready-p): New argument MODE, changed REPORT to QUIET, and
LANGUAGEs to LANGUAGE (now it can be a single symbol or a list of
them).
(treesit-major-mode-setup): New function.  Mostly comes from
treesit-mode.

* test/src/treesit-tests.el (treesit-misc): New test.

* lisp/progmodes/python.el (python-mode): Move some setup code into
the conditional branch at the end.

* lisp/progmodes/js.el (js-json-mode)
(js-mode): Move some setup code into the conditional branch at the
end.

* lisp/progmodes/ts-mode.el: Move tree-sitter setup into the
conditional branch.

1 files changed, 20 insertions, 0 deletions

diff --git a/test/src/treesit-tests.el b/test/src/treesit-tests.el
index adc17bc079a..2e26df69258 100644
--- a/test/src/treesit-tests.el
+++ b/test/src/treesit-tests.el
@@ -448,6 +448,26 @@ visible_end.)"
     ;; `treesit-search-forward-goto'
     ))
 
+(ert-deftest treesit-misc ()
+  "Misc helper functions."
+  (let ((settings '((t 0 t)
+                    (c-mode 1 t)
+                    (text-mode 2 nil)
+                    (prog-mode 3 t)
+                    (fundamental-mode 4 t))))
+    ;; `treesit--setting-for-mode'.
+    ;; Exact match.
+    (should (eq 1 (treesit--setting-for-mode 'c-mode settings)))
+    ;; Inherit from t.
+    (should (eq 0 (treesit--setting-for-mode 'non-exist settings)))
+    ;; Inherit from prog-mode rather than fundamental-mode.
+    (require 'elisp-mode)
+    (should (eq 3 (treesit--setting-for-mode 'emacs-lisp-mode settings)))
+    ;; Not inherit from text-mode.
+    (require 'outline)
+    (should (not (eq 2 (treesit--setting-for-mode 'outline-mode settings))))
+    ))
+
 ;; TODO
 ;; - Functions in treesit.el
 ;; - treesit-load-name-override-list