feat(wpcarro/emacs): Package bag.el

More Elisp packaging :)

Change-Id: I4cf5695fd97ed922b8dfe698a168061042208c73
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6001
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
Tested-by: BuildkiteCI

users/wpcarro/emacs/.emacs.d/wpc/bag.el

@@ -1,70 +0,0 @@
-;;; bag.el --- Working with bags (aka multi-sets) -*- lexical-binding: t -*-
-
-;; Author: William Carroll <wpcarro@gmail.com>
-;; Version: 0.0.1
-;; Package-Requires: ((emacs "24.3"))
-
-;;; Commentary:
-;; What is a bag?  A bag should be thought of as a frequency table.  It's a way
-;; to convert a list of something into a set that allows duplicates.  Isn't
-;; allowing duplicates the whole thing with Sets?  Kind of.  But the interface
-;; of Sets is something that bags resemble, so multi-set isn't as bag of a name
-;; as it may first seem.
-;;
-;; If you've used Python's collections.Counter, the concept of a bag should be
-;; familiar already.
-;;
-;; Interface:
-;; - add        :: x -> Bag(x) -> Bag(x)
-;; - remove     :: x -> Bag(x) -> Bag(x)
-;; - union      :: Bag(x) -> Bag(x) -> Bag(x)
-;; - difference :: Bag(x) -> Bag(x) -> Bag(x)
-
-;;; Code:
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; Dependencies
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(require 'al)
-(require 'number)
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; Library
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(cl-defstruct bag xs)
-
-(defun bag-update (f xs)
-  "Call F on alist in XS."
-  (let ((ys (bag-xs xs)))
-    (setf (bag-xs xs) (funcall f ys))))
-
-(defun bag-new ()
-  "Create an empty bag."
-  (make-bag :xs (al-new)))
-
-(defun bag-contains? (x xs)
-  "Return t if XS has X."
-  (al-has-key? x (bag-xs xs)))
-
-;; TODO: Tabling this for now since working with structs seems to be
-;; disappointingly difficult.  Where is `struct-update'?
-;; (defun bag-add (x xs)
-;;   "Add X to XS.")
-
-;; TODO: What do we name delete vs. remove?
-;; (defun bag-remove (x xs)
-;;   "Remove X from XS.
-;; This is a no-op is X doesn't exist in XS.")
-
-(defun bag-from-list (xs)
-  "Map a list of `XS' into a bag."
-  (->> xs
-       (list-reduce
-        (bag-new)
-        (lambda (x acc)
-          (bag-add x 1 #'number-inc acc)))))
-
-(provide 'bag)
-;;; bag.el ends here