feat: Add :defer-incrementally

Adds org-mode module for the sake of testing it.

README.org

@@ -91,7 +91,6 @@ On boot, ...
 
 - =/persist/vault/«user»= :: Persistent files belonging to specific users. This differs from the persistent home directories in that files are not necessarily linked anywhere.
 
-
 ** Deferring Emacs packages
 
 Nearly all configuration of Emacs packages happens under the ~use-package~ macro. ~use-package~ has various keywords with special syntax for common tasks, such as instrumenting hooks, setting keybindings, and customising variables. You may be surprised to learn that these are not /just/ syntactic sugar }:) (I was).
@@ -161,10 +160,16 @@ CLOSED: [2025-01-03 Fri 20:40]
 
 ***** TODO Dailies
 
+***** TODO Tags: project, readinglist
+
+Disassemble project-ideas.org and reading-list.org into a individual roam nodes.
+
 **** TODO Capture templates
 
 *** TODO project.el
 
+*** TODO Workspaces
+
 *** TODO Prose minor mode
 
 **** TODO Grammar-checking
@@ -447,6 +452,8 @@ https://discourse.nixos.org/t/what-to-do-with-a-full-boot-partition/2049
 
 Remove a given host from =~/.ssh/known_hosts=. Something like =sed -i -e '/192.168.122.54/d' .ssh/known_hosts=.
 
+Confirm by printing diff.
+
 *** TODO =lets-temp [NAME]=
 
 Create a new tempdir called ~[NAME]~, and cd into it.

users/crumb/programs/emacs/.persistent-scratch

@@ -1 +0,0 @@
-(["*scratch*" "ahhhii" (6) lisp-interaction-mode nil nil])

users/crumb/programs/emacs/init.el

@@ -19,6 +19,7 @@
 (require 'syd-display-startup-time)
 (require 'syd-evil)
 (require 'syd-keybinds)
+(require 'syd-org)
 (require 'syd-scratch)
 (require 'syd-smartparens)
 (require 'syd-ui)

users/crumb/programs/emacs/modules/syd-org.el

@@ -0,0 +1,23 @@
+;;; syd-org.el -*- lexical-binding: t; -*-
+
+(use-package org
+  :defer-incrementally
+  calendar find-func format-spec org-macs org-compat org-faces org-entities
+  org-list org-pcomplete org-src org-footnote org-macro ob org org-agenda
+  org-capture
+  :preface
+  (defvar org-modules
+    '(;; ol-w3m
+      ;; ol-bbdb
+      ol-bibtex
+      ;; ol-docview
+      ;; ol-gnus
+      ;; ol-info
+      ;; ol-irc
+      ;; ol-mhe
+      ;; ol-rmail
+      ;; ol-eww
+      )))
+
+(provide 'syd-org)
+;;; syd-org.el ends here

users/crumb/programs/emacs/modules/syd-use-package.el

@@ -0,0 +1,105 @@
+;;; syd-use-package.el -*- lexical-binding: t; -*-
+
+(defvar syd-incremental-idle-timer 0.75
+  "How long (in idle seconds) in between incrementally loading packages.")
+
+(defvar syd-incremental-first-idle-timer (if (daemonp) 0 2.0)
+  "How long (in idle seconds) until incremental loading starts.
+
+Set this to nil to disable incremental loading at startup.
+Set this to 0 to load all incrementally deferred packages immediately at
+`after-init-hook'.")
+
+(defvar syd-incremental-packages '(t)
+  "A list of packages to load incrementally after startup. Any large packages
+here may cause noticeable pauses, so it's recommended you break them up into
+sub-packages. For example, `org' is comprised of many packages, and might be
+broken up into:
+
+  (syd-load-packages-incrementally
+   '(calendar find-func format-spec org-macs org-compat
+     org-faces org-entities org-list org-pcomplete org-src
+     org-footnote org-macro ob org org-clock org-agenda
+     org-capture))
+
+This is already done by the lang/org module, however.
+
+If you want to disable incremental loading altogether, either remove
+`syd-load-packages-incrementally-h' from `after-init-hook' or set
+`syd-incremental-first-idle-timer' to nil. Incremental loading does not occur
+in daemon sessions (they are loaded immediately at startup).")
+
+(defun syd-load-packages-incrementally (packages &optional now)
+  "Registers PACKAGES to be loaded incrementally.
+
+If NOW is non-nil, PACKAGES will be marked for incremental loading next time
+Emacs is idle for `syd-incremental-first-idle-timer' seconds (falls back to
+`syd-incremental-idle-timer'), then in `syd-incremental-idle-timer' intervals
+afterwards."
+  (let* ((gc-cons-threshold most-positive-fixnum)
+         (first-idle-timer (or syd-incremental-first-idle-timer
+                               syd-incremental-idle-timer)))
+    (if (not now)
+        (cl-callf append syd-incremental-packages packages)
+      (while packages
+        (let ((req (pop packages))
+              idle-time)
+          (unless (featurep req)
+            (condition-case-unless-debug e
+                (and
+                 (or (null (setq idle-time (current-idle-time)))
+                     (< (float-time idle-time) first-idle-timer)
+                     (not
+                      (while-no-input
+                        ;; If `default-directory' doesn't exist or is
+                        ;; unreadable, Emacs throws file errors.
+                        (let ((default-directory user-emacs-directory)
+                              (inhibit-message t)
+                              (file-name-handler-alist
+                               (list (rassq 'jka-compr-handler file-name-handler-alist))))
+                          (message "loading %s" req)
+                          (require req nil t)
+                          t))))
+                 (push req packages))
+              (error
+               (message "Error: failed to incrementally load %S because: %s" req e)
+               (setq packages nil)))
+            (unless (null packages)
+              (run-at-time (if idle-time
+                               syd-incremental-idle-timer
+                             first-idle-timer)
+                           nil #'syd-load-packages-incrementally
+                           packages t)
+              (setq packages nil))))))))
+
+(defun syd-load-packages-incrementally-h ()
+  "Begin incrementally loading packages in `syd-incremental-packages'.
+
+If this is a daemon session, load them all immediately instead."
+  (when (numberp syd-incremental-first-idle-timer)
+    (if (zerop syd-incremental-first-idle-timer)
+        (mapc #'require (cdr syd-incremental-packages))
+      (run-with-idle-timer syd-incremental-first-idle-timer
+                           nil #'syd-load-packages-incrementally
+                           (cdr syd-incremental-packages) t))))
+
+(unless noninteractive
+  (add-hook 'after-init-hook #'syd-load-packages-incrementally-h 100))
+
+(with-eval-after-load 'use-package-core
+  (push :defer-incrementally use-package-deferring-keywords)
+  (setq use-package-keywords (use-package-list-insert
+                              :defer-incrementally use-package-keywords :after))
+  (defalias 'use-package-normalize/:defer-incrementally
+    #'use-package-normalize-symlist)
+  (defun use-package-handler/:defer-incrementally
+      (name _keyword targets rest state)
+    (use-package-concat
+     `((syd-load-packages-incrementally
+        ',(if (equal targets '(t))
+              (list name)
+            (append targets (list name)))))
+     (use-package-process-keywords name rest state))))
+
+(provide 'syd-use-package)
+;;; syd-use-package.el ends here