> I wrote another joke of this kind in APL News once long ago, > concerning a utility for printing sideways on fan-fold paper. It is > not difficult to prove that any computable function can be written in > one line of APL, and this provided a way of printing it. A single box > of 5000 sheets of fanfold paper was not quite a mile long. > > This is the sort of thing that got me my own entry in Stan > Kelly-Bootle's Computer Contradictionary, along with a two-page > article consisting entirely of empty array jokes for use in teaching, > as suggested by Jim Brown, then of IBM; and winning one of Stan's > programming contests in Unix Review. The programming contest was for > the maximum ratio of error text to program text. I submitted the APL > version of > > ".x=.'".x' > > which fills memory with stack frames, and then sets about displaying > them all in the WS FULL or equivalent error message. Again, this is > both joke and fact. APL implementors use such expressions to test the
In the same vein, in principle, fixed tacit adverbs are capable to compute whatever is computable, including evoking themselves anonymously ad nauseum. o=. @: an=. < o ((,'0') ,&< ]) NB. Atomizing a noun (verb) dn=. `(an _) NB. Dummy noun (_) ev=. `:6 c=. "_ 1 2 3 (c (% o) dn ev) 1 0.5 0.333333 ar=. 5!:1@< a=. (c ((an , ]) o) dn ev) ((ar'a')a) -: (((ar'a')a)ev) NB. ((ar'a')a) is its own gerundial representation (so to speak)... 1 NB. What follows potentially answers my own question in: NB. http://www.jsoftware.com/pipermail/programming/2008-April/010356.html a=. (c ((an , ]) o) dn ev) ev a=. 'a'f. a (((("_)((<@:((,'0') ,&< ]) , ])@:))(`_))(`:6))(`:6) (ar'a')('a'f.) NB. BEWARE! The result of this expression is a fixed tacit adverbial counterpart of (".x=.'".x') and (128!:2)~'(128!:2)~')... Puzzle: write directly the expression without any pronouns. ________________________________________ From: programming-boun...@jsoftware.com [programming-boun...@jsoftware.com] on behalf of Roger Hui [rogerhui.can...@gmail.com] Sent: Monday, April 02, 2012 10:15 AM To: Programming forum Subject: Re: [Jprogramming] CS Jokes (was Re: Functors in mathematics, Haskell and an example in J) http://www.jsoftware.com/jwiki/Essays/Covert%20Representation On Mon, Apr 2, 2012 at 3:51 AM, Edward Mokurai Cherlin < moku...@sugarlabs.org> wrote: > On Sun, April 1, 2012 2:51 pm, Raul Miller wrote: > > P.S. after reading your example and seeing that you > > using the shape (with a prefix of 0) to hold the data > > I am wondering if this was meant to be an april fool's > > joke? > > I have observed that it is possible, in a hypothetical way, to > represent any computable function using only empty arrays if we have > no limitation on the number of dimensions. A Computer Science fact > that is also a joke. > > I wrote another joke of this kind in APL News once long ago, > concerning a utility for printing sideways on fan-fold paper. It is > not difficult to prove that any computable function can be written in > one line of APL, and this provided a way of printing it. A single box > of 5000 sheets of fanfold paper was not quite a mile long. > > This is the sort of thing that got me my own entry in Stan > Kelly-Bootle's Computer Contradictionary, along with a two-page > article consisting entirely of empty array jokes for use in teaching, > as suggested by Jim Brown, then of IBM; and winning one of Stan's > programming contests in Unix Review. The programming contest was for > the maximum ratio of error text to program text. I submitted the APL > version of > > ".x=.'".x' > > which fills memory with stack frames, and then sets about displaying > them all in the WS FULL or equivalent error message. Again, this is > both joke and fact. APL implementors use such expressions to test the > quality of their memory handling, in particular whether they have > saved enough memory in WS FULL situations to handle generating the > error message--obviously without creating it as an object in the > workspace first. > > > -- > > Raul > > -- > Edward Mokurai (默雷/निशब्दगर्ज/نشبدگرج) Cherlin > Silent Thunder is my name, and Children are my nation. > The Cosmos is my dwelling place, the Truth my destination. > http://wiki.sugarlabs.org/go/Replacing_Textbooks > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm [BEST LLC] Bayesian Efficient Strategic Trading LLC The information in this communication and any attachment is confidential and intended solely for the attention and use of the named addressee(s). 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