"Nothing Will Happen", Split, Croatia, 19-22 August 2010.




Nothing will happen is a regional hackmeeting. During the first two days there is event "Inlaws and Outlaws" and the issues of "pirate vs. reformatory approach to the problems of restrictive regime/practice of protection of intelectual property (patents)" will be discussed. There is no specific theme for other two days. The program will be negotiated on place.




Split is beautiful, ancient city on Mediterranean, Adriatic coast.


I'd be there, and I'll probably have some talk on Lisp. I'm thinking on one Oleg Kiselyov's macro, hygienic FEXPR's in Newlisp or something on Shutt's Kernel. I didn't decided yet. Few other Lispers from Croatia and Hungary will be on conference. Accommodation and food is free or cheap (~ $25/day), there is no cotisation.

If you're interested, you're invited to join.



---

Using (sin cos 0.5) instead of (sin (cos 0.5)) in Newlisp.




; Recently, Jeremy Dunn on Newlisp forum expressed desire to use
; the single argument functions in Newlisp in following fashion:
;
;     (sin cos 0.5) = (sin (cos 0.5))
;     
; The motivation is well know in Lisp world: avoidance of parentheses.
; I believe that regularity of the Lisp syntax should be preserved
; and that it is better to be consistent, although more verbose.
;
; However, the problem is interesting.
;
; At least two works are already done in Newlisp in that dyrection. Cyril
; Slobin described make-pass macro:
;
;         http://slobin.livejournal.com/148287.html
;
; (define-macro (make-pass)
;   (doargs (arg)
;     (letex ((Old arg)
;             (New (sym (append (string arg) "&"))))
;       (define-macro (New)
;         (Old (eval (args)))))))
;
; (make-pass catch not print)
;
; Here is how it works:
;
; (catch& while (read-line)
;   (setq line (current-line))
;   (if (not& empty? line)
;     (print& format "%s\n" line)
;     (throw 'empty)))
;
; My construct for composition of arbitrary functions
; or fexprs should be mentioned as well.
;
;   http://kazimirmajorinc.blogspot.com/2010/02/composition-of-functions-or-macros.html
;
; Its syntax should be:
;
; ((compose sin cos) 0.5)
;
; Needless to say, compose is "in the spirit" of the Lisp,
; but it is syntactically heavier than original (sin (cos 0.5)).
; And Jeremy didn't liked even Cyril's (sin& cos 5).
;
; So, I adapted Cyril's idea to work without that extra &, but
; then it had to work both like sin& and original sin.

(println (sin 3))
(println (sin (cos 4)))
(println (sin (cos (sin 5))))

; 0.1411200081
; -0.6080830096
; 0.5433319155

(define-macro (make-pass-adapted)
  (doargs (arg)
     (constant arg
        (letex((arg (eval arg)))
           (lambda-macro()
              (arg (eval (if (> (length (args)) 1)
                             (args)
                             (first (args))))))))))
        
(make-pass-adapted sin cos)

(println (sin (+ (cos 0) (cos 0) (cos 0))))
(println (sin cos 4))
(println (sin cos sin (+ 2 3)))

; 0.1411200081
; -0.6080830096
; 0.5433319155

; I'll test it whether it works with Cyril's example.

 (make-pass-adapted catch not print)   
 
 (catch while (read-line)
   (setq line (current-line))
   
   (if (not empty? line)
     (print format "%s\n" line)
     (throw 'empty)))
     
; It's really easy, so I had doubt whether it is important enough
; to blog about that, lets say, sinful sin. However, I noticed
; that it is interesting example of the function that is replaced
; with FEXPR.