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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/set.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/set.el')
-rw-r--r--configs/shared/.emacs.d/wpc/set.el92
1 files changed, 92 insertions, 0 deletions
diff --git a/configs/shared/.emacs.d/wpc/set.el b/configs/shared/.emacs.d/wpc/set.el
new file mode 100644
index 000000000000..fd86f9033cc3
--- /dev/null
+++ b/configs/shared/.emacs.d/wpc/set.el
@@ -0,0 +1,92 @@
+;;; set.el --- Working with mathematical sets -*- lexical-binding: t -*-
+;; Author: William Carroll <wpcarro@gmail.com>
+
+;;; Commentary:
+;; The set data structure is a collection that deduplicates its elements.
+
+;;; Code:
+
+(require 'ht) ;; friendlier API for hash-tables
+(require 'dotted)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Wish List
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;; - TODO: Support enum protocol for set.
+;; - TODO: Prefer a different hash-table library that doesn't rely on mutative
+;;   code.
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Library
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(cl-defstruct set xs)
+
+(defun set/from-list (xs)
+  "Create a new set from the list XS."
+  (make-set :xs (->> xs
+                     (list/map #'dotted/new)
+                     ht-from-alist)))
+
+(defun set/new (&rest args)
+  "Create a new set from ARGS."
+  (set/from-list args))
+
+(defun set/to-list (xs)
+  "Map set XS into a list."
+  (->> xs
+       set-xs
+       ht-keys))
+
+(defun set/add (x xs)
+  "Add X to set XS."
+  (struct/update set
+                 xs
+                 (lambda (table)
+                   (let ((table-copy (ht-copy table)))
+                     (ht-set table-copy x 10)
+                     table-copy))
+                 xs))
+
+(defun set/count (xs)
+  "Return the number of elements in XS."
+  (->> xs
+       set-xs
+       ht-size))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Predicates
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defun set/empty? (xs)
+  "Return t if XS has no elements in it."
+  (= 0 (set/count xs)))
+
+(defun set/contains? (x xs)
+  "Return t if set XS has X."
+  (ht-contains? (set-xs xs) x))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Tests
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defconst set/enable-testing? t
+  "Run tests when t.")
+
+(when set/enable-testing?
+  (progn
+    ;; {from,to}-list
+    (prelude/assert (equal '(1 2 3)
+                           (->> '(1 1 2 2 3 3)
+                                set/from-list
+                                set/to-list)))
+    ;; empty?
+    (prelude/assert (set/empty? (set/new)))
+    (prelude/refute (set/empty? (set/new 1 2 3)))
+    ;; count
+    (prelude/assert (= 0 (set/count (set/new))))
+    (prelude/assert (= 2 (set/count (set/new 1 1 2 2))))))
+
+(provide 'set)
+;;; set.el ends here