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
This commit is contained in:
William Carroll 2022-07-29 18:26:43 -07:00 committed by clbot
parent 6b3f4113cc
commit 7410928b5b
3 changed files with 95 additions and 25 deletions

View file

@ -8,7 +8,7 @@
;; 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
;; of Sets is something that bags resemble, so multi-set isn't as bad of a name
;; as it may first seem.
;;
;; If you've used Python's collections.Counter, the concept of a bag should be
@ -27,7 +27,7 @@
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(require 'al)
(require 'number)
(require 'list)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Library
@ -35,36 +35,44 @@
(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-from-list (xs)
"Map a list of `XS' into a bag."
(->> xs
(list-reduce (bag-new) #'bag-add)))
(defun bag-add (x xs)
"Add X to XS."
(if (bag-contains? x xs)
(struct-update
bag xs (lambda (xs) (al-update x (lambda (x) (+ 1 x)) xs)) xs)
(struct-update bag xs (lambda (xs) (al-set x 1 xs)) xs)))
(defun bag-remove (x xs)
"Remove X from XS.
This is a no-op is X doesn't exist in XS."
(when (bag-contains? x xs)
(struct-update bag xs (lambda (xs) (al-delete x xs)) xs)))
(defun bag-count (x xs)
"Return the number of occurrences of X in XS."
(al-get x (bag-xs xs) 0))
(defun bag-total (xs)
"Return the total number of elements in XS."
(->> (bag-xs xs)
(al-reduce 0 (lambda (_key v acc) (+ acc v)))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Predicates
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(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

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@ -0,0 +1,26 @@
{ pkgs, depot, ... }:
let
bag = pkgs.callPackage
({ emacsPackages }:
emacsPackages.trivialBuild {
pname = "bag";
version = "1.0.0";
src = ./bag.el;
packageRequires =
(with depot.users.wpcarro.emacs.pkgs; [
al
list
]);
})
{ };
emacs = (pkgs.emacsPackagesFor pkgs.emacs28).emacsWithPackages (epkgs: [ bag ]);
in
bag.overrideAttrs (_old: {
doCheck = true;
checkPhase = ''
${emacs}/bin/emacs -batch \
-l ert -l ${./tests.el} -f ert-run-tests-batch-and-exit
'';
})

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@ -0,0 +1,36 @@
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Dependencies
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(require 'ert)
(require 'bag)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Tests
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(setq fixture (bag-from-list '(1 1 1 2 2 3)))
(ert-deftest bag-add ()
(and
(not (bag-contains? 4 fixture))
(bag-contains? 4 (bag-add 4 fixture))))
(ert-deftest bag-remove ()
(and
(bag-contains? 1 fixture)
(not (bag-contains? 3 (bag-remove 3 fixture)))))
(ert-deftest bag-count ()
(and
(= 3 (bag-count 1 fixture))
(= 2 (bag-count 2 fixture))
(= 1 (bag-count 3 fixture))))
(ert-deftest bag-total ()
(= 6 (bag-total fixture)))
(ert-deftest bag-contains? ()
(and
(bag-contains? 1 fixture)
(not (bag-contains? 4 fixture))))