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
