;;; bench/pcase.el --- Exercise code using pcase  -*- lexical-binding: t; -*-

;; Copyright (C) 2020-2021 Free Software Foundation, Inc.

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

(eval-and-compile
  ;; ¡FIXME!  The GNUmakefile of elpa.git uses:
  ;;
  ;;    ... -L $(dir $@) -f batch-byte-compile $<
  ;;
  ;; to compile each file.  This is handy for some cases such as files in
  ;; `contrib' subdirectories but for this `pcase.el' file it causes this
  ;; `pcase.el' to hide the *real* `pcase.el'.  So we workaround this problem
  ;; here by removing the offending element from `load-path'.  Yuck!
  ;;
  ;; We should probably change GNUmakefile instead so it doesn't forcefully
  ;; add the directory to `load-path', e.g. make this dependent on the
  ;; presence of special file like `.dont-add-to-load-path'. 
  (let ((file (if (fboundp 'macroexp-file-name) (macroexp-file-name) ;Emacs≥28
                (or load-file-name
                    (bound-and-true-p byte-compile-current-file)))))
    (when file
      (setq load-path (remove (file-name-directory file) load-path)))))

;;; Commentary:

;; Apply a simple pattern match defined with pcase on the element of a list.

;;; Code:

(require 'cl-lib)

(defvar elb-pcase-len 5000)
(defvar elb-pcase-list (cl-loop repeat elb-pcase-len
				collect (cl-case (random 3)
					  (0 '(a b))
					  (1 '(a))
					  (2 (random 10)))))

(defsubst foo (x)
  (1+ x))

(defsubst bar (x)
  (* x x))

(defun elb-pcase (l)
  (cl-loop for x in l
	   counting (pcase x
		      (`(a b) 1)
		      (`(a) 2)
		      (_ (foo (bar x))))))

(defun elb-pcase-entry ()
  (cl-loop repeat 20000
	   do (elb-pcase elb-pcase-list)))

(provide 'elb-pcase)