ADD dependency management and conditional loading

etc/conf.org

@@ -162,10 +162,16 @@ OS is one of those in `system-type'."
   `(when (not (eq system-type ,os)) (progn ,@body)
      (print "Skipping OS-restricted code")))
 
+(defvar nd/required-exes '()
+  "Running list of executables required to run various configuations.")
+
 (defmacro nd/when-bin (bin &rest body)
   "Execute BODY if the program BIN exists."
   (declare (indent 1))
-  `(if (executable-find ,bin) (progn ,@body)
+  `(if (executable-find ,bin)
+       (progn
+         (setq nd/required-exes (-union '(,bin) nd/required-exes))
+         ,@body)
      (print (format "Executable %s not found. Skipping." ,bin))))
 
 (defmacro nd/time-exec (&rest body)
@@ -262,6 +268,27 @@ If FRONT is t, do to the front of current values instead of the back."
   (--each
       (where-is-internal f keymap nil nil)
     (define-key keymap it nil)))
+
+(defun nd/detect-package-manager ()
+  "Return the package manager being used on this OS."
+  (cond
+   ;; for now only pacman...because arch is the best (TM)
+   ((file-exists-p "/usr/bin/pacman")
+    'pacman)))
+
+(defun nd/pacman-find-owner (file)
+  "Return the pacman packages that owns FILE.
+Assumes pacman is installed and FILE is an absolute path."
+  (-some->> (format "pacman -Fq %s" file)
+            (shell-command-to-string)
+            (s-trim)
+            (s-split "\n")
+            (--map (replace-regexp-in-string ".*/" "" it t))
+            (cons file)))
+
+(defun nd/detect-dependencies ()
+  "Return a list of required packages for this configuration."
+  (--map (nd/pacman-find-owner (format "/usr/bin/%s" it)) nd/required-exes))
 #+END_SRC
 ** interactive
 :PROPERTIES:
@@ -807,6 +834,7 @@ For me this means R but ess also supports S-plus, SAS, Stata, and other statisti
 Flycheck syntax checkers
 - r-lintr (install from CRAN)
 #+begin_src emacs-lisp
+(nd/when-bin "R"
   (defun nd/init-ess-company ()
     "Set the company backends for ess modes."
     (setq-local company-backends '((company-R-objects company-R-args))))
@@ -842,25 +870,28 @@ Flycheck syntax checkers
         ((#'inferior-ess--start-process :around #'nd/ess-r-add-env))
       (apply orig-fun args)))
 
+  (advice-add #'run-ess-r :around #'nd/ess-r-start-env)
+
+  (nd/when-bin "docker"
     (defun nd/ess-r-setwd-maybe (orig-fun &rest args)
         (nd/with-advice
             ((#'ess-set-working-directory :override #'ignore))
         (apply orig-fun args)))
 
-(advice-add #'run-ess-r :around #'nd/ess-r-start-env)
-
     (advice-add #'run-ess-r :around #'nd/ess-r-setwd-maybe)
 
-;; force flycheck to use the system-wide R install instead of whatever
-;; is in docker
+    ;; force flycheck to use system R instead of whatever is in docker
     (defun nd/flycheck-find-exe-no-docker (orig-fun exe)
         (if (or (equal exe "R") (s-starts-with? "R " exe))
             "/bin/R" (funcall orig-fun exe)))
 
     (advice-add #'flycheck-default-executable-find :around
-            #'nd/flycheck-find-exe-no-docker)
+                #'nd/flycheck-find-exe-no-docker)))
 #+END_SRC
 *** C
+:PROPERTIES:
+:ID:       0ee09480-e722-4a06-af8f-52f7dbf3f906
+:END:
 #+BEGIN_SRC emacs-lisp
 (defun nd/init-c-company ()
   "Set the company backends for anaconda mode."
@@ -869,19 +900,21 @@ Flycheck syntax checkers
                                  company-irony)))
 
 ;; requires clang (duh)
+(nd/when-bin "clang"
   (use-package flycheck-clang-analyzer
     :straight t
     :after flycheck
     :config
-  (flycheck-clang-analyzer-setup))
+    (flycheck-clang-analyzer-setup)))
 
 ;; requires cmake/llvm
+(nd/when-bin "cmake"
   (use-package irony
     :straight t
     :hook ((irony-mode . irony-cdb-autosetup-compile-options)))
 
   (use-package company-irony
-  :straight t)
+    :straight t))
 
 (use-package company-c-headers
   :straight t)
@@ -948,8 +981,9 @@ Anaconda (not related to the Python/R distribution?) is much lighter and easier
 :END:
 [[https://github.com/python/black][Black]] is a really nice syntax formatter. It must be externally installed to work.
 #+BEGIN_SRC emacs-lisp
+(nd/when-bin "black"
   (use-package blacken
-  :straight t)
+    :straight t))
 #+END_SRC
 **** pyenv
 :PROPERTIES:
@@ -959,6 +993,7 @@ For isolation I use [[https://github.com/pyenv/pyenv][pyenv]] and [[https://gith
 
 Note this also requires all external packages to be installed in each environement (eg ipython, black, flake8, and pylint).
 #+BEGIN_SRC emacs-lisp
+(nd/when-bin "pyenv"
   (use-package pyenv-mode
     :straight t
     :after python
@@ -968,7 +1003,7 @@ Note this also requires all external packages to be installed in each environeme
 
   ;; resolve symlinks when setting the pyenv, otherwise we get some
   ;; strange errors when activating a symlinked env
-(advice-add #'pyenv-mode-full-path :filter-return #'file-truename)
+  (advice-add #'pyenv-mode-full-path :filter-return #'file-truename))
 #+END_SRC
 *** Ruby
 :PROPERTIES:
@@ -1007,6 +1042,7 @@ Since most of these need GHCi to run properly, I added a hook to load haskell so
 
 I have also found this to be much simpler and conflicting with other packages such as =dante= and =intero= (and probably =haskell-ide-engine= and friends).
 #+BEGIN_SRC emacs-lisp
+(nd/when-bin "stack"
   (defun nd/init-haskell-company ()
     "Set the company backends for haskell mode."
     (setq-local company-backends
@@ -1049,7 +1085,7 @@ I have also found this to be much simpler and conflicting with other packages su
   (delight 'interactive-haskell-mode nil "haskell")
 
   ;; unnecessary to see on the modeline
-(delight 'subword-mode nil "subword")
+  (delight 'subword-mode nil "subword"))
 #+END_SRC
 **** hlint
 :PROPERTIES:
@@ -1057,8 +1093,9 @@ I have also found this to be much simpler and conflicting with other packages su
 :END:
 This is an additional syntax checker and requires the =hlint= binary (install through stack).
 #+BEGIN_SRC emacs-lisp
+(nd/when-bin "hlint"
   (with-eval-after-load 'haskell
-  (flycheck-add-next-checker 'haskell-stack-ghc '(t . haskell-hlint)))
+    (flycheck-add-next-checker 'haskell-stack-ghc '(t . haskell-hlint))))
 #+END_SRC
 **** helper functions
 :PROPERTIES:
@@ -1081,8 +1118,9 @@ Other helper functions that make haskell even more fun.
 :END:
 For flycheck, install =luacheck= (from AUR on Arch).
 #+BEGIN_SRC emacs-lisp
+(nd/when-bin "luacheck"
   (use-package lua-mode
-  :straight t)
+    :straight t))
 #+END_SRC
 *** TeX
 **** AUCTeX
@@ -1245,6 +1283,9 @@ Overlays hex color codes with matching colors in certain modes like css and html
   :straight t)
 #+END_SRC
 *** Jinja2
+:PROPERTIES:
+:ID:       a38b0792-46fe-43cc-b57a-d8e3a189fdc5
+:END:
 #+BEGIN_SRC emacs-lisp
 (use-package jinja2-mode
   :straight t
@@ -1365,11 +1406,15 @@ No custom code here, but flycheck needs =sqlint= (on Arch available through the
 :ID:       ce24b075-ede6-4d6c-81db-4c6aa40e4fd0
 :END:
 #+BEGIN_SRC emacs-lisp
+(nd/when-bin "docker"
   (use-package dockerfile-mode
-  :straight t)
+    :straight t))
 #+END_SRC
 ** testing
 *** buttercup
+:PROPERTIES:
+:ID:       9539395e-98aa-4e47-b2ff-4233b63d40b1
+:END:
 Include this so I can have the docs and indentation specs handy when writing test suites
 #+BEGIN_SRC emacs-lisp
 (use-package buttercup
@@ -3380,12 +3425,13 @@ For some reason there is no default way to get a "print prompt." Instead one nee
 :ID:       67e11402-a9e5-4aae-8644-0e2c4f9ad2bc
 :END:
 #+BEGIN_SRC emacs-lisp
+(nd/when-bin "git"
   (use-package magit
     :straight t
     :config
     :delight auto-revert-mode
     (setq magit-push-always-verify nil
-        git-commit-summary-max-length 50))
+          git-commit-summary-max-length 50)))
 #+END_SRC
 ** dired
 *** no confirm
@@ -4615,6 +4661,9 @@ The function keys are nice because they are almost (not always) free in every mo
   ("=" #'balance-windows :exit t))
 #+END_SRC
 *** other
+:PROPERTIES:
+:ID:       dff1f586-7231-4394-8f4c-2730dbe8a901
+:END:
 #+BEGIN_SRC emacs-lisp
 ;; exchange point and marker (I never saw the use for this)
 (global-unset-key (kbd "C-x C-x"))