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Diffstat (limited to 'users/wpcarro/emacs/.emacs.d/wpc/list.el')
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diff --git a/users/wpcarro/emacs/.emacs.d/wpc/list.el b/users/wpcarro/emacs/.emacs.d/wpc/list.el deleted file mode 100644 index 2f1509eeb4a9..000000000000 --- a/users/wpcarro/emacs/.emacs.d/wpc/list.el +++ /dev/null @@ -1,221 +0,0 @@ -;;; list.el --- Functions for working with lists -*- lexical-binding: t -*- - -;; Author: William Carroll <wpcarro@gmail.com> -;; Version: 0.0.1 -;; Package-Requires: ((emacs "24")) - -;;; Commentary: -;; Since I prefer having the `list-' namespace, I wrote this module to wrap many -;; of the functions that are defined in the the global namespace in ELisp. I -;; sometimes forget the names of these functions, so it's nice for them to be -;; organized like this. -;; -;; Motivation: -;; Here are some examples of function names that I cannot tolerate: -;; - `car': Return the first element (i.e. "head") of a linked list -;; - `cdr': Return the tail of a linked list - -;; As are most APIs for standard libraries that I write, this is heavily -;; influenced by Elixir's standard library. -;; -;; Elixir's List library: -;; - ++/2 -;; - --/2 -;; - hd/1 -;; - tl/1 -;; - in/2 -;; - length/1 -;; -;; Similar libraries: -;; - dash.el: Functional library that mimmicks Clojure. It is consumed herein. -;; - list-utils.el: Utility library that covers things that dash.el may not -;; cover. -;; stream.el: Elisp implementation of streams, "implemented as delayed -;; evaluation of cons cells." - -;; TODO: Consider naming this file linked-list.el. - -;; TODO: Support module-like macro that auto-namespaces functions. - -;; TODO: Consider wrapping most data structures like linked-lists, -;; associative-lists, etc in a `cl-defstruct', so that the dispatching by type -;; can be nominal instead of duck-typing. I'm not sure if this is a good idea -;; or not. If I do this, I should provide isomorphisms to map between idiomatic -;; ways of working with Elisp data structures and my wrapped variants. - -;; TODO: Are function aliases/synonyms even a good idea? Or do they just -;; bloat the API unnecessarily? - -;;; Code: - -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; Dependencies -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - -;; TODO: Move `prelude-assert' elsewhere so that I can require it without -;; introducing the circular dependency of list.el -> prelude.el -> list.el. -;;(require 'prelude) -(require 'dash) - -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; Constants -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - -(defconst list-tests? t - "When t, run the test suite.") - -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; Library -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - -(defun list-new () - "Return a new, empty list." - '()) - -(defun list-concat (&rest lists) - "Joins `LISTS' into on list." - (apply #'-concat lists)) - -(defun list-join (joint xs) - "Join a list of strings, XS, with JOINT." - (if (list-empty? xs) - "" - (list-reduce (list-first xs) - (lambda (x acc) - (string-concat acc joint x)) - (list-tail xs)))) - -(defun list-length (xs) - "Return the number of elements in `XS'." - (length xs)) - -(defun list-get (i xs) - "Return the value in `XS' at `I', or nil." - (nth i xs)) - -(defun list-head (xs) - "Return the head of `XS'." - (car xs)) - -;; TODO: Learn how to write proper function aliases. -(defun list-first (xs) - "Alias for `list-head' for `XS'." - (list-head xs)) - -(defun list-tail (xs) - "Return the tail of `XS'." - (cdr xs)) - -(defun list-reverse (xs) - "Reverses `XS'." - (reverse xs)) - -(defun list-cons (x xs) - "Add `X' to the head of `XS'." - (cons x xs)) - -;; map, filter, reduce - -;; TODO: Create function adapters like swap. -;; (defun adapter/swap (f) -;; "Return a new function that wraps `F' and swaps the arguments." -;; (lambda (a b) -;; (funcall f b a))) - -;; TODO: Make this function work. -(defun list-reduce (acc f xs) - "Return over `XS' calling `F' on an element in `XS'and `ACC'." - (-reduce-from (lambda (acc x) (funcall f x acc)) acc xs)) - -(defun list-map (f xs) - "Call `F' on each element of `XS'." - (-map f xs)) - -(defun list-map-indexed (f xs) - "Call `F' on each element of `XS' along with its index." - (-map-indexed (lambda (i x) (funcall f x i)) xs)) - -(defun list-filter (p xs) - "Return a subset of XS where predicate P returned t." - (list-reverse - (list-reduce - '() - (lambda (x acc) - (if (funcall p x) - (list-cons x acc) - acc)) - xs))) - -(defun list-reject (p xs) - "Return a subset of XS where predicate of P return nil." - (list-filter (lambda (x) (not (funcall p x))) xs)) - -(defun list-find (p xs) - "Return the first x in XS that passes P or nil." - (-find p xs)) - -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; Predicates -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - -(defun list-instance? (xs) - "Return t if `XS' is a list. -Be leery of using this with things like alists. Many data structures in Elisp - are implemented using linked lists." - (listp xs)) - -(defun list-empty? (xs) - "Return t if XS are empty." - (= 0 (list-length xs))) - -(defun list-all? (p xs) - "Return t if all `XS' pass the predicate, `P'." - (-all? p xs)) - -(defun list-any? (p xs) - "Return t if any `XS' pass the predicate, `P'." - (-any? p xs)) - -(defun list-contains? (x xs) - "Return t if X is in XS using `equal'." - (-contains? xs x)) - -(defun list-xs-distinct-by? (f xs) - "Return t if all elements in XS are distinct after applying F to each." - (= (length xs) - (->> xs (-map f) set-from-list set-count))) - -;; TODO: Support dedupe. -;; TODO: Should we call this unique? Or distinct? - -;; TODO: Add tests. -(defun list-dedupe-adjacent (xs) - "Return XS without adjacent duplicates." - (prelude-assert (not (list-empty? xs))) - (list-reduce (list (list-first xs)) - (lambda (x acc) - (if (equal x (list-first acc)) - acc - (list-cons x acc))) - xs)) - -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; -;; Tests -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - -;; (when list-tests? -;; (prelude-assert -;; (= 0 -;; (list-length '()))) -;; (prelude-assert -;; (= 5 -;; (list-length '(1 2 3 4 5)))) -;; (prelude-assert -;; (= 16 -;; (list-reduce 1 (lambda (x acc) (+ x acc)) '(1 2 3 4 5)))) -;; (prelude-assert -;; (equal '(2 4 6 8 10) -;; (list-map (lambda (x) (* x 2)) '(1 2 3 4 5))))) - -(provide 'list) -;;; list.el ends here |