;;; -*- lexical-binding: t -*-
;;
;; -----------------------------------------------------------------------------
;; this file:
;;   https://dataswamp.org/~incal/peval/peval.el
;; -----------------------------------------------------------------------------

(require 'cl-lib)
(cl-pushnew (expand-file-name ".") load-path :test #'string=)

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(let ((dm "peval.so"))
  (load dm nil t)
  (declare-function peval dm))

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(require 'benchmark)
(require 'calc-comb)
(require 'cl-lib)

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(defun peval--eform (&rest form)
  (format "%s" (eval (car form))))

;; (peval--eform (+ 1 3 3 7)) ; "14"

;; -----------------------------------------------------------------------------

(defun peval--primes-num (beg end &optional vrb)
  (cl-loop
   for i from beg to end
   count (= 1 (calcFunc-prime i)) into res
   if vrb finally do (message "%d" res)
   finally return res))

;; (peval--primes-num 1 99 t)

;; -----------------------------------------------------------------------------

(defun peval-test ()
  (let* ((beg 1)
         (int 2)
         (exp 22)
         (end (expt int exp))
         (crs 8)
         (prts `(,beg
                 ,@(butlast
                    (cdr
                     (mapcar #'floor
                      (number-sequence beg end (/ (- end beg 0.0) crs)))))
                 ,end))
         (i 0)
         (del (make-string 44 ?\-))
         (peval-res 0)
         (peval-time
          (benchmark-elapse
            (mapc
             (lambda (s) (cl-incf peval-res (string-to-number s)))
             (peval
              `(peval--primes-num ,beg               ,(nth (cl-incf i) prts)) ; 1
              `(peval--primes-num ,(1+ (nth i prts)) ,(nth (cl-incf i) prts)) ; 2
              `(peval--primes-num ,(1+ (nth i prts)) ,(nth (cl-incf i) prts)) ; 3
              `(peval--primes-num ,(1+ (nth i prts)) ,(nth (cl-incf i) prts)) ; 4
              `(peval--primes-num ,(1+ (nth i prts)) ,(nth (cl-incf i) prts)) ; 5
              `(peval--primes-num ,(1+ (nth i prts)) ,(nth (cl-incf i) prts)) ; 6
              `(peval--primes-num ,(1+ (nth i prts)) ,(nth (cl-incf i) prts)) ; 7
              `(peval--primes-num ,(1+ (nth i prts)) ,end)))))                ; 8
         (elisp-res 0)
         (elisp-time
          (benchmark-elapse
            (setf elisp-res (peval--primes-num beg end))))
         (optimal-time (/ elisp-time (* 1.0 crs)))
         (peval-perc   (* 100 (/ peval-time   (* 1.0 elisp-time))))
         (optimal-perc (* 100 (/ optimal-time (* 1.0 peval-time)))))
    (cl-flet ((report (fun)
                (funcall fun "%s" del)
                (funcall fun "[intro] parallel `peval' vs sequential Elisp")
                (funcall fun "[emacs] GNU Emacs %s" emacs-version)
                (funcall fun "[scope] %d^%d = %d" int exp end)
                (funcall fun "%s" del)
                (funcall fun "[elisp] (Emacs = %d) %d %.1f s" 1        elisp-res elisp-time)
                (funcall fun "[peval] (Emacs = %d) %d %.1f s" (1+ crs) peval-res peval-time)
                (funcall fun "[peval] %.1f%% runtime" peval-perc)
                (funcall fun "[peval] %.1f%% optimal" optimal-perc)))
      (if noninteractive
          (report #'message)
        (when-let* ((buf (get-buffer-create "*peval*"))
                    (_   (bufferp buf)))
          (with-current-buffer buf
            (erase-buffer)
            (report (lambda (s) (insert (format "%s\n" s))))
            (goto-char (point-min)))
          (pop-to-buffer buf))))))

;; (peval-test)

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(provide 'peval)

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