diff options
author | William Carroll <wpcarro@gmail.com> | 2022-07-29T03·29-0700 |
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committer | clbot <clbot@tvl.fyi> | 2022-07-29T03·35+0000 |
commit | 15c9ff49026f9ddbb42f663dfbc2668faa74cab2 (patch) | |
tree | 23da6e794623f267bfcc53802cd654e3d655dba9 /users/wpcarro/emacs/pkgs/set/set.el | |
parent | caf068253a8e7eacff0b255de66f830e726d6777 (diff) |
feat(wpcarro/emacs): Package al, list, set, struct r/4342
Originally I set-out to package `al.el`, but as I started traversing the dependencies, I needed to package increasingly more packages. I refactored some of these to prune their dependencies to slay this hydra before it turned into a never-ending project. I have mixed feelings about this. I also introduced `ert` and unit tests into my Elisp packaging, so it'll be nice to have build-time tests that run when Emacs updates land in depot. Change-Id: I2756dc60888b80255a495e08ae61bd547e6b3db2 Reviewed-on: https://cl.tvl.fyi/c/depot/+/5998 Reviewed-by: wpcarro <wpcarro@gmail.com> Autosubmit: wpcarro <wpcarro@gmail.com> Tested-by: BuildkiteCI
Diffstat (limited to 'users/wpcarro/emacs/pkgs/set/set.el')
-rw-r--r-- | users/wpcarro/emacs/pkgs/set/set.el | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/users/wpcarro/emacs/pkgs/set/set.el b/users/wpcarro/emacs/pkgs/set/set.el new file mode 100644 index 000000000000..2d6e14917a45 --- /dev/null +++ b/users/wpcarro/emacs/pkgs/set/set.el @@ -0,0 +1,116 @@ +;;; set.el --- Working with mathematical sets -*- lexical-binding: t -*- + +;; Author: William Carroll <wpcarro@gmail.com> +;; Version: 0.0.1 +;; Package-Requires: ((emacs "24.3")) + +;;; Commentary: +;; The set data structure is a collection that deduplicates its elements. + +;;; Code: + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; Dependencies +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +(require 'cl-lib) +(require 'dash) +(require 'ht) ;; friendlier API for hash-tables +(require 'struct) + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; 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 + (-map (lambda (x) (cons x nil))) + 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 nil) + table-copy)) + xs)) + +;; TODO: Ensure all `*/reduce' functions share the same API. +(defun set-reduce (acc f xs) + "Return a new set by calling F on each element of XS and ACC." + (->> xs + set-to-list + (-reduce-from (lambda (acc x) (funcall f x acc)) acc))) + +(defun set-intersection (a b) + "Return the set intersection between A and B." + (set-reduce (set-new) + (lambda (x acc) + (if (set-contains? x b) + (set-add x acc) + acc)) + a)) + +(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)) + +;; TODO: Prefer using `ht.el' functions for this. +(defun set-equal? (a b) + "Return t if A and B share the name members." + (ht-equal? (set-xs a) + (set-xs b))) + +(defun set-distinct? (a b) + "Return t if A and B have no shared members." + (set-empty? (set-intersection a b))) + +(defun set-superset? (a b) + "Return t if A has all of the members of B." + (->> b + set-to-list + (-all? (lambda (x) (set-contains? x a))))) + +(defun set-subset? (a b) + "Return t if each member of set A is present in set B." + (set-superset? b a)) + +(provide 'set) +;;; set.el ends here |