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authorWilliam Carroll <wpcarro@gmail.com>2019-10-09T11·13+0100
committerWilliam Carroll <wpcarro@gmail.com>2019-12-24T15·21+0000
commit6b456c1b7a4f6899f063a6e65355af51901d9c7a (patch)
treecfc70d74818ae9fabdbbfb0cf16cce092e4c1a09 /configs/shared/.emacs.d/wpc/monoid.el
parenta7c72adb2ebec1e497fc040eaf3551d564d61a5b (diff)
Massive configuration overhaul
Currently paying the price of months of non-diligent git usage.

Here's what has changed.

- Theming support in Gvcci and wpgtk
- Dropping support for i3
- Supporting EXWM
- Many Elisp modules
- Collapsed redundant directories in ./configs
Diffstat (limited to 'configs/shared/.emacs.d/wpc/monoid.el')
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diff --git a/configs/shared/.emacs.d/wpc/monoid.el b/configs/shared/.emacs.d/wpc/monoid.el
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+;;; monoid.el --- Working with Monoids in Elisp -*- lexical-binding: t -*-
+;; Author: William Carroll <wpcarro@gmail.com>
+
+;;; Commentary:
+;; The day has finally arrived where I'm using Monoids in Elisp.
+;;
+;; The monoid typeclass is as follows:
+;; - empty :: a
+;; - concat :: (list a) -> a
+
+;;; Code:
+
+;; TODO: Consider a prelude version that works for all Elisp types.
+(defun monoid/classify (xs)
+  "Return the type of `XS'."
+  (cond
+   ((listp xs) 'list)
+   ((vectorp xs) 'vector)
+   ((stringp xs) 'string)))
+
+
+(defun monoid/empty (xs)
+  "Return the empty monoid for the type `XS'."
+  (pcase (monoid/classify xs)
+    ('list '())
+    ('vector [])
+    ('string "")))
+
+(provide 'monoid)
+;;; monoid.el ends here