mirror of
https://git.savannah.gnu.org/git/guile.git
synced 2025-04-29 19:30:36 +02:00
673509f84f
safe/evil.scm, safe/README, modules/README, modules/main, modules/module-0.scm, modules/module-1.scm, modules/module-2.scm: Minor cleanup. * README: Added intro stuff, restructured a bit. * box-dynamic/README, box-module/README, box/README: Cleanup and restructuring. * box-dynamic-module/box-mixed.scm: New file, demonstrating usage of extension library functionality, but without exporting procedures from the library. Thanks to Thomas Wawrzinek for the idea and example code! * box-dynamic-module/box-module.scm: Add comments, export make-box, box-ref, box-set!. * box-dynamic-module/README: Integrate new module (box-mixed), restructure and cleanup a bit.
69 lines
1.6 KiB
Scheme
Executable file
69 lines
1.6 KiB
Scheme
Executable file
#! /usr/local/bin/guile -s
|
|
!#
|
|
;;; Commentary:
|
|
|
|
;;; This is a command-line factorial calculator. Run like this:
|
|
;;;
|
|
;;; ./fact 5
|
|
;;;
|
|
;;; to calculate the factorial of 5
|
|
|
|
;;; Author: Martin Grabmueller
|
|
;;; Date: 2001-05-29
|
|
|
|
;;; Code:
|
|
|
|
(use-modules (ice-9 getopt-long))
|
|
|
|
;; This is the grammar for the command line synopsis we expect.
|
|
;;
|
|
(define command-synopsis
|
|
'((version (single-char #\v) (value #f))
|
|
(help (single-char #\h) (value #f))))
|
|
|
|
;; Display version information and exit.
|
|
;;
|
|
(define (display-version)
|
|
(display "fact 0.0.1\n"))
|
|
|
|
;; Display the usage help message and exit.
|
|
;;
|
|
(define (display-help)
|
|
(display "Usage: fact [options...] number\n")
|
|
(display " --help, -h Show this usage information\n")
|
|
(display " --version, -v Show version information\n"))
|
|
|
|
;; Interpret options, if --help or --version was given, print out the
|
|
;; requested information and exit. Otherwise, calculate the factorial
|
|
;; of the argument.
|
|
;;
|
|
(define (main options)
|
|
(let ((help-wanted (option-ref options 'help #f))
|
|
(version-wanted (option-ref options 'version #f))
|
|
(args (option-ref options '() '())))
|
|
(cond
|
|
((or version-wanted help-wanted)
|
|
(if version-wanted
|
|
(display-version))
|
|
(if help-wanted
|
|
(display-help)))
|
|
((not (= (length args) 1))
|
|
(display-help))
|
|
(else
|
|
(display (fact (string->number (car args))))
|
|
(newline)))))
|
|
|
|
;; Calculate the factorial of n.
|
|
;;
|
|
(define (fact n)
|
|
(if (< n 2)
|
|
1
|
|
(* n (fact (- n 1)))))
|
|
|
|
;; Call the main program with parsed command line options.
|
|
;;
|
|
(main (getopt-long (command-line) command-synopsis))
|
|
|
|
;; Local variables:
|
|
;; mode: scheme
|
|
;; End:
|