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

1 files changed, 0 insertions, 254 deletions

diff --git a/users/wpcarro/emacs/.emacs.d/wpc/al.el b/users/wpcarro/emacs/.emacs.d/wpc/al.el
deleted file mode 100644
index 3cf98fee296b..000000000000
--- a/users/wpcarro/emacs/.emacs.d/wpc/al.el
+++ /dev/null
@@ -1,254 +0,0 @@
-;;; al.el --- Interface for working with associative lists -*- lexical-binding: t -*-
-
-;; Author: William Carroll <wpcarro@gmail.com>
-;; Version: 0.0.1
-;; Package-Requires: ((emacs "25.1"))
-
-;;; Commentary:
-;; Firstly, a rant:
-;; In most cases, I find Elisp's APIs to be confusing.  There's a mixture of
-;; overloaded functions that leak the implementation details (TODO: provide an
-;; example of this.) of the abstract data type, which I find privileges those
-;; "insiders" who spend disproportionately large amounts of time in Elisp land,
-;; and other functions with little-to-no pattern about the order in which
-;; arguments should be applied.  In theory, however, most of these APIs could
-;; and should be much simpler.  This module represents a step in that direction.
-;;
-;; I'm modelling these APIs after Elixir's APIs.
-;;
-;; On my wishlist is to create protocols that will allow generic interfaces like
-;; Enum protocols, etc.  Would be nice to abstract over...
-;; - associative lists (i.e. alists)
-;; - property lists (i.e. plists)
-;; - hash tables
-;; ...with some dictionary or map-like interface.  This will probably end up
-;; being quite similar to the kv.el project but with differences at the API
-;; layer.
-;;
-;; Similar libraries:
-;; - map.el: Comes bundled with recent versions of Emacs.
-;; - asoc.el: Helpers for working with alists.  asoc.el is similar to alist.el
-;;   because it uses the "!" convention for signalling that a function mutates
-;;   the underlying data structure.
-;; - ht.el: Hash table library.
-;; - kv.el: Library for dealing with key-value collections.  Note that map.el
-;;   has a similar typeclass because it works with lists, hash-tables, or
-;;   arrays.
-;; - a.el: Clojure-inspired way of working with key-value data structures in
-;; Elisp.  Works with alists, hash-tables, and sometimes vectors.
-;;
-;; Some API design principles:
-;; - The "noun" (i.e. alist) of the "verb" (i.e. function) comes last to improve
-;; composability with the threading macro (i.e. `->>') and to improve consumers'
-;; intuition with the APIs.  Learn this once, know it always.
-;;
-;; - Every function avoids mutating the alist unless it ends with !.
-;;
-;; - CRUD operations will be named according to the following table:
-;;   - "create" *and* "set"
-;;   - "read"   *and* "get"
-;;   - "update"
-;;   - "delete" *and* "remove"
-;;
-;; For better or worse, all of this code expects alists in the form of:
-;; ((first-name . "William") (last-name . "Carroll"))
-;;
-;; Special thanks to github.com/alphapapa/emacs-package-dev-handbook for some of
-;; the idiomatic ways to update alists.
-;;
-;; TODO: Include a section that compares alist.el to a.el from
-;; github.com/plexus/a.el.
-
-;;; Code:
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; Dependencies:
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(require 'macros)
-(require 'dash)
-(require 'tuple)
-(require 'maybe)
-
-;; TODO: Support function aliases for:
-;; - create/set
-;; - read/get
-;; - update
-;; - delete/remove
-
-;; Support mutative variants of functions with an ! appendage to their name.
-
-;; Ensure that the same message about only updating the first occurrence of a
-;; key is consistent throughout documentation using string interpolation or some
-;; other mechanism.
-
-;; TODO: Consider wrapping all of this with `(cl-defstruct alist xs)'.
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; Constants
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(defconst al-enable-tests? t
-  "When t, run the test suite.")
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; Library
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-;; TODO: Support a variadic version of this to easily construct alists.
-(defun al-new ()
-  "Return a new, empty alist."
-  '())
-
-;; Create
-;; TODO: See if this mutates.
-(defun al-set (k v xs)
-  "Set K to V in XS."
-  (if (al-has-key? k xs)
-      (progn
-        ;; Note: this is intentional `alist-get' and not `al-get'.
-        (setf (alist-get k xs) v)
-        xs)
-    (list-cons `(,k . ,v) xs)))
-
-(defun al-set! (k v xs)
-  "Set K to V in XS mutatively.
-Note that this doesn't append to the alist in the way that most alists handle
-  writing.  If the k already exists in XS, it is overwritten."
-  (map-delete xs k)
-  (map-put! xs k v))
-
-;; Read
-(defun al-get (k xs)
-  "Return the value at K in XS; otherwise, return nil.
-Returns the first occurrence of K in XS since alists support multiple entries."
-  (cdr (assoc k xs)))
-
-(defun al-get-entry (k xs)
-  "Return the first key-value pair at K in XS."
-  (assoc k xs))
-
-;; Update
-;; TODO: Add warning about only the first occurrence being updated in the
-;; documentation.
-(defun al-update (k f xs)
-  "Apply F to the value stored at K in XS.
-If `K' is not in `XS', this function errors.  Use `al-upsert' if you're
-interested in inserting a value when a key doesn't already exist."
-  (if (not (al-has-key? k xs))
-      (error "Refusing to update: key does not exist in alist")
-    (al-set k (funcall f (al-get k xs)) xs)))
-
-(defun al-update! (k f xs)
-  "Call F on the entry at K in XS.
-Mutative variant of `al-update'."
-  (al-set! k (funcall f (al-get k xs))xs))
-
-;; TODO: Support this.
-(defun al-upsert (k v f xs)
-  "If K exists in `XS' call `F' on the value otherwise insert `V'."
-  (if (al-has-key? k xs)
-      (al-update k f xs)
-    (al-set k v xs)))
-
-;; Delete
-;; TODO: Make sure `delete' and `remove' behave as advertised in the Elisp docs.
-(defun al-delete (k xs)
-  "Deletes the entry of K from XS.
-This only removes the first occurrence of K, since alists support multiple
-  key-value entries.  See `al-delete-all' and `al-dedupe'."
-  (remove (assoc k xs) xs))
-
-(defun al-delete! (k xs)
-  "Delete the entry of K from XS.
-Mutative variant of `al-delete'."
-  (delete (assoc k xs) xs))
-
-;; Additions to the CRUD API
-;; TODO: Implement this function.
-(defun al-dedupe-keys (xs)
-  "Remove the entries in XS where the keys are `equal'.")
-
-(defun al-dedupe-entries (xs)
-  "Remove the entries in XS where the key-value pair are `equal'."
-  (delete-dups xs))
-
-(defun al-keys (xs)
-  "Return a list of the keys in XS."
-  (mapcar 'car xs))
-
-(defun al-values (xs)
-  "Return a list of the values in XS."
-  (mapcar 'cdr xs))
-
-(defun al-has-key? (k xs)
-  "Return t if XS has a key `equal' to K."
-  (maybe-some? (assoc k xs)))
-
-(defun al-has-value? (v xs)
-  "Return t if XS has a value of V."
-  (maybe-some? (rassoc v xs)))
-
-(defun al-count (xs)
-  "Return the number of entries in XS."
-  (length xs))
-
-;; TODO: Should I support `al-find-key' and `al-find-value' variants?
-(defun al-find (p xs)
-  "Find an element in XS.
-
-Apply a predicate fn, P, to each key and value in XS and return the key of the
-first element that returns t."
-  (let ((result (list-find (lambda (x) (funcall p (car x) (cdr x))) xs)))
-    (if result
-        (car result)
-      nil)))
-
-(defun al-map-keys (f xs)
-  "Call F on the values in XS, returning a new alist."
-  (list-map (lambda (x)
-              `(,(funcall f (car x)) . ,(cdr x)))
-            xs))
-
-(defun al-map-values (f xs)
-  "Call F on the values in XS, returning a new alist."
-  (list-map (lambda (x)
-              `(,(car x) . ,(funcall f (cdr x))))
-            xs))
-
-(defun al-reduce (acc f xs)
-  "Return a new alist by calling F on k v and ACC from XS.
-F should return a tuple.  See tuple.el for more information."
-  (->> (al-keys xs)
-       (list-reduce acc
-                    (lambda (k acc)
-                      (funcall f k (al-get k xs) acc)))))
-
-(defun al-merge (a b)
-  "Return a new alist with a merge of alists, A and B.
-In this case, the last writer wins, which is B."
-  (al-reduce a #'al-set b))
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; Tests
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(when al-enable-tests?
-  (prelude-assert
-   (equal '((2 . one)
-            (3 . two))
-          (al-map-keys #'1+
-                          '((1 . one)
-                            (2 . two)))))
-  (prelude-assert
-   (equal '((one . 2)
-            (two . 3))
-          (al-map-values #'1+
-                            '((one . 1)
-                              (two . 2))))))
-
-
-;; TODO: Support test cases for the entire API.
-
-(provide 'al)
-;;; al.el ends here