subtree(users/wpcarro): docking briefcase at '24f5a642'

git-subtree-dir: users/wpcarro
git-subtree-mainline: 464bbcb15c
git-subtree-split: 24f5a642af
Change-Id: I6105b3762b79126b3488359c95978cadb3efa789

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

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+;;; prelude.el --- My attempt at augmenting Elisp stdlib -*- lexical-binding: t -*-
+
+;; Author: William Carroll <wpcarro@gmail.com>
+;; Version: 0.0.1
+;; Package-Requires: ((emacs "24.3"))
+;; Homepage: https://user.git.corp.google.com/wpcarro/briefcase
+
+;;; Commentary:
+;; Some of these ideas are scattered across other modules like `fs',
+;; `string-functions', etc.  I'd like to keep everything modular.  I still don't
+;; have an answer for which items belond in `misc'; I don't want that to become
+;; a dumping grounds.  Ideally this file will `require' all other modules and
+;; define just a handful of functions.
+
+;; TODO: Consider removing all dependencies from prelude.el.
+
+;;; Code:
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Dependencies
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(require 'dash)
+(require 's)
+(require 'f)
+(require 'cl-lib)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Utilities
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defun prelude-to-string (x)
+  "Convert X to a string."
+  (format "%s" x))
+
+(defun prelude-inspect (&rest args)
+  "Message ARGS where ARGS are any type."
+  (->> args
+       (-map #'prelude-to-string)
+       (apply #'s-concat)
+       message))
+
+(defmacro prelude-call-process-to-string (cmd &rest args)
+  "Return the string output of CMD called with ARGS."
+  `(with-temp-buffer
+     (call-process ,cmd nil (current-buffer) nil ,@args)
+     (buffer-string)))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Assertions
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;; TODO: Should I `throw' instead of `error' here?
+(defmacro prelude-assert (x)
+  "Errors unless X is t.
+These are strict assertions and purposely do not rely on truthiness."
+  (let ((as-string (prelude-to-string x)))
+    `(unless (equal t ,x)
+       (error (s-concat "Assertion failed: " ,as-string)))))
+
+(defmacro prelude-refute (x)
+  "Errors unless X is nil."
+  (let ((as-string (prelude-to-string x)))
+    `(unless (equal nil ,x)
+       (error (s-concat "Refutation failed: " ,as-string)))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Adapter functions
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defun prelude-identity (x)
+  "Return X unchanged."
+  x)
+
+(defun prelude-const (x)
+  "Return a variadic lambda that will return X."
+  (lambda (&rest _) x))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Miscellaneous
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;; TODO: Consider packaging these into a linum-color.el package.
+;; TODO: Generate the color used here from the theme.
+(defvar prelude--linum-safe? nil
+  "Flag indicating whether it is safe to work with function `linum-mode'.")
+
+(defvar prelude--linum-mru-color nil
+  "Stores the color most recently attempted to be applied.")
+
+(add-hook 'linum-mode-hook
+          (lambda ()
+            (setq prelude--linum-safe? t)
+            (when (maybe-some? prelude--linum-mru-color)
+              (set-face-foreground 'linum prelude--linum-mru-color))))
+
+(defun prelude-set-line-number-color (color)
+  "Safely set linum color to `COLOR'.
+
+If this is called before Emacs initializes, the color will be stored in
+`prelude--linum-mru-color' and applied once initialization completes.
+
+Why is this safe?
+If `(set-face-foreground 'linum)' is called before initialization completes,
+Emacs will silently fail.  Without this function, it is easy to introduce
+difficult to troubleshoot bugs in your init files."
+  (if prelude--linum-safe?
+      (set-face-foreground 'linum color)
+    (setq prelude--linum-mru-color color)))
+
+(defun prelude-prompt (prompt)
+  "Read input from user with PROMPT."
+  (read-string prompt))
+
+(cl-defun prelude-start-process (&key name command)
+  "Pass command string, COMMAND, and the function name, NAME.
+This is a wrapper around `start-process' that has an API that resembles
+`shell-command'."
+  ;; TODO: Fix the bug with tokenizing here, since it will split any whitespace
+  ;; character, even though it shouldn't in the case of quoted string in shell.
+  ;; e.g. - "xmodmap -e 'one two three'" => '("xmodmap" "-e" "'one two three'")
+  (prelude-refute (s-contains? "'" command))
+  (let* ((tokens (s-split " " command))
+         (program-name (nth 0 tokens))
+         (program-args (cdr tokens)))
+    (apply #'start-process
+           `(,(format "*%s<%s>*" program-name name)
+             ,nil
+             ,program-name
+             ,@program-args))))
+
+(defun prelude-executable-exists? (name)
+  "Return t if CLI tool NAME exists according to the variable `exec-path'."
+  (let ((file (locate-file name exec-path)))
+    (require 'maybe)
+    (if (maybe-some? file)
+        (f-exists? file)
+      nil)))
+
+(defmacro prelude-time (x)
+  "Print the time it takes to evaluate X."
+  `(benchmark 1 ',x))
+
+(provide 'prelude)
+;;; prelude.el ends here