init

uldb.el

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+;;; uldb.el --- An ultralight database for composition. -*- lexical-binding: t -*-
+
+;; by bth
+
+;; An ultralight database for writing and project composition, using only unique
+;; filenames, POSIX filesystem conventions, and the builtin `project' package.
+
+;; This is somewhat like org-roam, except without any database dependency. (And
+;; it uses Markdown rather than org, which I don't care for.)
+
+;; This depends on a few simple ideas:
+
+;; 1. A numbered filename specification which serves as unique id.
+
+;; 2. Placing that same id into the file header, so that concatenated files
+;; have reference back to their source.
+
+;; 3. Using a source "journal/" directory, where source files should first be
+;; composed and where we can assume a file exists if not elsewhere.
+
+;; 4. Using the built-in `project' package to organize compositions built from
+;; these source files.
+
+;; 5. (Optional) Use `embark' to visit files with a single keystroke.
+
+;; features provided:
+;; `uldb-journal-header' defines the standard header
+
+;; `uldb-project-find-meta' via `project-switch-project': open a file like
+;; *meta.md in a given project.
+
+;; `uldb-file-at-point-advice' via `embark-dwim': open file in known projects
+;; with fallback to journal/
+
+;; `uldb-grep-tag': search files with same tag
+
+(require 'package)
+
+;; Primary path glob for the journal. This allows various mountpoints.
+
+(setq uldb-journal-path-glob ".*/writing/journal")
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; journal header
+
+(defun uldb-iso-8601 ()
+  "Insert a date stamp in ISO 8601 order, but with periods in place of dashes."
+  (format-time-string "%Y.%m.%d")
+  )
+
+(defun uldb-journal-header ()
+  "Create a uldb-journal header composed of:
+# buffer-name minus the .md file type
+: date
+"
+   (interactive)
+   (insert
+    (format "# %s\n: %s\n\n" (substring (buffer-name) 0 -3) (uldb-iso-8601))
+    )
+   )
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; journal/.project.el
+
+;; normally .git detection works fine. But for my journal/ I don't git.
+;; https://michael.stapelberg.ch/posts/2021-04-02-emacs-project-override/
+(defun uldb-project-override (dir)
+    "Returns the parent directory containing a .project.el file,
+ if any, to override the standard project.el detection logic when
+ needed.
+"
+    (let ((override (locate-dominating-file dir ".project.el")))
+      (if override
+          (list 'vc nil override)
+        nil)))
+;; Cannot use :hook because 'project-find-functions does not end in -hook
+(add-hook 'project-find-functions #'uldb-project-override)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; find-file-at-point
+
+;; the journal/ serves as content origin, so it must be treated specially.
+(setq uldb-journal-path (car (seq-filter
+                         (lambda (path)
+                           ;; this way I don't have to hardcode the full path:
+                           (string-match uldb-journal-path-glob path))
+                         ;; stores all project roots in a list of strings:
+                         (project-known-project-roots))))
+
+;;;;;;;;;;;;;;;;;;;;;
+;; find-file C-x C-f solution
+;; combined with the hook into `file-name-at-point-functions', this means I can
+;; run find-file at point, followed by M-n :
+(defun uldb-journal-find-file ()
+  (let ((default-directory uldb-journal-path)
+        (thing (thing-at-point 'filename))
+        )
+    (expand-file-name thing))
+)
+(add-hook 'file-name-at-point-functions 'uldb-journal-find-file nil t)
+
+;;;;;;;;;;;;;;;;;;
+;; Embark solution (optional)
+
+;; Load this with an advice:
+;; (advice-add 'embark-target-file-at-point :around 'uldb-file-at-point-advice)
+
+;; `embark-target-file-at-point' uses `ffap-file-at-point', which uses
+;; `default-directory' to expand the filename.
+
+;; NOTE: decided to use an advice rather than add my own function to
+;; `embark-target-finders', since I'd have to remove the file finder and put my
+;; function in the same place in the list anyway.
+
+(defun uldb-file-at-point-advice (origfunc)
+  "Like find-file-at-point, but checks all known project paths.
+
+In this order:
+1. current project root
+2. all other project roots
+3. journal/ path
+
+Since journal/ is the origin and other projects shadow it.
+
+TODO: Use a special directory name for potentials/ or the like, in case it's not
+in the root dir.
+"
+  (or
+   ;; current project
+   (funcall origfunc)
+
+   ;; all other projects
+   (let ((result))
+     (cl-loop for project-path in
+              (seq-remove
+               (lambda (path)
+                 (or (string-match uldb-journal-path path)
+                     (when (project-current)
+                       (string-match (caddr (project-current)) path))
+                     ))
+               (project-known-project-roots))
+              do (let ((default-directory project-path))
+                   (setq result (funcall origfunc)))
+              if result
+              return result
+              ))
+
+   ;; journal path
+   (let ((default-directory uldb-journal-path))
+     (funcall origfunc))
+   ))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; C-x p p
+
+(defun uldb-project-find-meta ()
+  (interactive)
+  ;; this works because `project-switch-project' overrides the dir:
+  (find-file (expand-file-name "*meta.md" (caddr (project-current))) t)
+  )
+
+;; overwrite
+(setq project-switch-commands
+      '(
+        (uldb-project-find-meta "open meta" "m")
+        (project-dired "dired")
+        (project-find-file "find file")
+        (project-find-regexp "find regexp")
+        ))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; tags
+
+;; TODO: do I want to search all projects?
+(defun uldb-grep-tag ()
+  "Run project-find-regexp on the current identifer as a journal frontmatter tag.
+
+NOTE: this searches in the current project root only.
+"
+  (interactive)
+  (project-find-regexp (concat "\\+\\ " (thing-at-point 'word)))
+  )
+
+;; NOTE: to export files with a given tag:
+;; grep -l '\+ TAG' *md | xargs cp -t /tmp/
+;; note the -l flag to grep to output files only, and the -t flag to cp to
+;; specify a target dir (since it appends the list from xargs I think).
+;; Or, in dired, run `find-grep-dired'.
+
+
+(provide 'uldb)