Prev: Lisp meeting in Warsaw
Next: A question (confusion) about closure
From: Slobodan Blazeski on 6 May 2008 12:18
On May 6, 4:45 pm, Slobodan Blazeski <slobodan.blaze...(a)gmail.com>
wrote:
> On May 6, 4:23 pm, Slobodan Blazeski <slobodan.blaze...(a)gmail.com>
> wrote:
>
>
>
>
>
> > On May 5, 3:00 pm, Ken Tilton <kennytil...(a)optonline.net> wrote:
>
> > > Slobodan Blazeski wrote:
> > > > On May 4, 4:15 am, Ken Tilton <kennytil...(a)optonline.net> wrote:
>
> > > >>Slobodan Blazeski wrote:
>
> > > >>>On May 2, 1:00 pm, "John Thingstad" <jpth...(a)online.no> wrote:
>
> > > >>>>På Fri, 02 May 2008 05:02:03 +0200, skrev Ken Tilton
> > > >>>><kennytil...(a)optonline.net>:
>
> > > >>>>>Everyone knows how much I love Arc, I guess it has influenced my Lisp:
>
> > > >>>>>(deftoc |Reducing|
> > > >>>>>    (category "Algebra I"  "Fractions")
> > > >>>>>  (genner
> > > >>>>>   (easy
> > > >>>>>    (w (n (rr 2 6))
> > > >>>>>      (m/ n (* n (rr 2 9)))))
> > > >>>>>   (avg
> > > >>>>>    (dsb (n d cf)
> > > >>>>>        (sort (rpu 3 (rr 2 9)) '<)
> > > >>>>>      (m/ (* n cf) (* d cf))))
> > > >>>>>   (hard
> > > >>>>>    (dsb (n d cf)
> > > >>>>>      (rpu 3 (rr 2 12))
> > > >>>>>      (m/ (* n cf) (* d cf)))
> > > >>>>>    (dsb (n1 n2 d1 d2)
> > > >>>>>      (subseq (shuffle (list 2 3 5 7 9 11 13)) 0 4)
> > > >>>>>      (m/ (* n1 n2) (* d1 d2))))))
>
> > > >>>>>[The neat thing being one DSL within another DSL. (This Algebra
> > > >>>>>application just screams for DSLs because of the repeated coding of
> > > >>>>>different Algebraic transformations.)]
>
> > > >>>>>Btw, the "genner" clause hard-codes random problem generation.
>
> > > >>>>>Hmmm. Where'd the prolog go? Ah, different problem (halfway down):
>
> > > >>>>>(deftoc add-real
> > > >>>>>    (title "Adding")
> > > >>>>>    (category "Algebra I" "Real Numbers")
> > > >>>>>  (genner
> > > >>>>>   (easy
> > > >>>>>    (m+ (rp 2 (r+ 12)))
> > > >>>>>    (m+ (rp 2 (r- 12)))
> > > >>>>>    (eo (m+ 0 (r+ 12))
> > > >>>>>      (m+ (r+ 12) 0))
> > > >>>>>    (w (n (r+ 12))
> > > >>>>>      (eo (m+ n (- n))
> > > >>>>>        (m+ (- n) n))))
> > > >>>>>   (avg
> > > >>>>>    ;; --- two approaches to same thing, without prolog..
> > > >>>>>    (w (ns (rpu 2 (r+ 12)))
> > > >>>>>      (eo (m+ (car ns) (- (cadr ns)))
> > > >>>>>        (m+ (- (car ns)) (cadr ns))))
> > > >>>>>    ;; ---- ...and with prolog
> > > >>>>>    (plogn
> > > >>>>>     (generating ?x (fgen (random 12)))
> > > >>>>>     (generating ?y (fgen (random 12)))
> > > >>>>>     (lispp (/= ?x ?y))
> > > >>>>>     (eo (m+ ?x (- ?y))
> > > >>>>>       (m+ (- ?x) ?y))))
> > > >>>>>   (hard
> > > >>>>>    (plogn
> > > >>>>>     (generating ?ns (fgen (rp (eo 3 4) (eo (r+ 12)(r- 12)))))
> > > >>>>>     (lispp (and (+? (ct-if '+? ?ns))
> > > >>>>>              (+? (ct-if '-? ?ns))))
> > > >>>>>     (m+ ?ns)))))
>
> > > >>>>>I highlighted above a for-the-fun-of-it with/without Prolog pair,
> > > >>>>>fascinating that the prolog variant is so much easier to code and so
> > > >>>>>much more verbose. Usually goes the other way.
>
> > > >>>>>Anyway, looking ahead I can almost guarantee the prolog approach will
> > > >>>>>win out -- I have been through this before. In C. Twenty years ago. I
> > > >>>>>haven't forgotten the agony of enforcing constraints in procedural code.
>
> > > >>>>>Meanwhile, what a pleasure to be doing /applications/ again with Lisp,
> > > >>>>>erecting version 1.0 of a random problem generation framework in an easy
> > > >>>>>day. Noobs, as much as you dig Lisp, have no idea how much fun it will
> > > >>>>>be three years in when it disappears and you can Just Build Apps.
>
> > > >>>>>kenny
>
> > > >>>>Just in case I am not on your "kill" list. I have sided with Pascal in
> > > >>>>that full words are better.
>
> > > >>>I vote for full words , though look at a dictionary and try to find
> > > >>>shortest synonym.
> > > >>>Very-long-and-descriptive-names sucks. But code that looks like a
> > > >>>three-year-old with a particular fondness for periods and colons was
> > > >>>set before the keyboard.  (http://www.jsoftware.com/help/jforc/contents.htm)
>
> > > >>This is very disappointing.
>
> > > >>We already have on the table Tilton's Law of Abbreviation, signifying my
> > > >>concurrence with the general rule, and I have gone to the trouble of
> > > >>pointing out why this situation is exceptional, yet not not one of you
> > > >>has said one word addressing the validity of the exception, which is the
> > > >>only issue on the table given my concurrence with the general rule.
>
> > > >>The earnest dullard can follow rules, the craftsman knows when they do
> > > >>not apply. This is the thing we cannot teach, to expert systems or even
> > > >>good students. It requires a meta-understanding of the rule, an
> > > >>understanding of from where the rule came and then whether the
> > > >>circumstances at hand come from the same place.
>
> > > >>And what do I hear from You People? A cast in concrete knee-jerk rote
> > > >>repeating snap-saluting line-toeing mindless recitation of something you
> > > >>read in chapter 3 of a programming proverbs book.
>
> > > >>Super. You got 5 points from your teacher who was looking for The One
> > > >>Right Answer and you just flunked out of the U. of Kenny.
>
> > > > Kenny I've read your explanation but I still disagree with you it has
> > > > nothing to do listening some teacher  or fallowing some cast in
> > > > concrete rule. It just the way I feel it's right.
> > > > Take for example assignment operator:
> > > > cl     setf
> > > > scheme set!
> > > > q      :
> > > > j      =:
> > > > c++    =
>
> > > > For anybody using the language more than 3 days it would be crystal
> > > > clear what this do.Because we're getting use to parse those *symbols*.
> > > > Also in case of c++ we have even different meaning, because = in math
> > > > means SAME. In case of j we have to understand what's that strange
> > > > equal.
> > > > But what if we use ASSIGN like (assign foo 4) <=> (setf  foo 4) Assign
> > > > is already prebuilt in our knowledge of english meaning we don't hog
> > > > any more of our brain resources to parse the setf set! or :   It's
> > > > longer but tolerable. We have to type 6 characters but we release our
> > > > brain resources from context switching and symbol lookup. If we are so
> > > > on shortness maybe using IS is better. Not clear as ASSIGN but still
> > > > brain resources are lower. Think (is foo 4) or in tradition syntax foo
> > > > is 4; // looks like cobol?   So adding a lot of meaningless
> > > > abbreviations like above is just not my style. Your brain might
> > > > function differently, but I have a natural tendency to remove brain
> > > > hogging coming from long functions, abreviations or shortcuts. I know
> > > > that each thing takes only a negligeble thing but they quickly add up.
> > > > This is the reason I don't like Emacs YMMV.
>
> > > Jeez, it's a simple question:
>
> > > This?:
>
> > >   (mx-generate #\-
> > >    (mx-generate #\*
> > >      (random-in-range 2 9)
> > >      (random-in-range 2 9))
> > >    (random-in-range 2 9))
>
> > > ...or this:
>
> > >    (m- (m* (rr 2 9)(rr 2 9))
> > >        (rr 2 9)))
>
> > > ...or maybe something infixy and even closer to what I am trying to
> > > express (hint) like this:
>
> > >     "r2[9]*r2[9]-r2[9]"
>
> > > ...or some other infix/string scheme?
>
> > In Edi
> > (hook (create #\-) (create #\* dup) (random 2 9))
> > Where:
> > 1. (hook fn1 fn2 atom) => (fn (fn2 atom) atom))
> > 2. If (define create (x &rest args) ...) then
> > (create #\-) => (lambda (&rest args) (apply create #\- args))
> > 3. Dup is a operator that tells how many  copies of the argument
> > should be supplied :
> > (m* (rr 2 9)(rr 2 9) (rr 2 9)) <=> (m* (dup 2)
> > 4. (random x y) is ... you know
>
> Sorry I forget to give you a credit for in-the-name instructions, edi
> is polymorhic, so what if there is monadic create then below wouldn't
> work
> (create #\-) => (lambda (&rest args) (apply create #\- args)) sp using
> in-the-name instructions
> (create\2 #\-)  meaning I'm talking about dyadic create. Something
> they're nifty but I prefer to avoid them so final result
> (hook (create\2 #\-) (create\2 #\* dup) (random 2 9)) or
> (hook (dyad create #\-) (dyad create #\* dup) (random 2 9))- Hide quoted text -
>
> - Show quoted text -

My mistake, you can't use hook because you'll only get a single random
so you're stack with
(create #\- (create #\* (random 2 9) (random 2 9)) (random 2 9)) as
random is not a functional operator.
First  |  Prev  | 
Pages: 1 2
Prev: Lisp meeting in Warsaw
Next: A question (confusion) about closure