> On Wed, May 27, 2009 at 4:03 PM, Roger Hui <[email protected]> wrote: >> If you have the time and energy, see >> http://www.jsoftware.com/jwiki/Essays/From_APL_to_J > > I have read some of these earlier. I particularly liked the first few > articles which tell how Ken has started to invent APL, showing how > some unnecessary primitives (like the extra transpose operators) have > disappeared early.
No wait, those are different articles. The ones I referred to here are really the ones linked from "http://www.jsoftware.com/jwiki/Doc/A%20Source%20Book%20in%20APL";, especially the very first one, Formalism in Programming Languages, and apart from the extra transposition monad (|:&.:|.) it also defines monadic and diadic symbols for some simple vectors and matrices which these days we just compute from iota. It does not use bracketed axis, but only variant symbols for the other axis of a matrix for which some APL uses symbols overstruck with a minus. Also, I think, the append operator (comma) is missing. Ambrus ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
