Hi. Could someone please shed some light on the following behavior:
1p1 3.14159 0p1 0 0p0 0 1x1 2.71828 0x1 2.71828 0x0 0 I don't understand why 0x1 isn't the same as 0 * ^1 even though other constants seem to obey this form. I haven't found any explanation in http://www.jsoftware.com/docs/help806/dictionary/dcons.htm . <information irrelevant to the question> I am new to J and am yet to write a useful script in it, but I've already been greatly impressed by how consistent the language felt in most cases. For example, just the other day I wrote a monadic verb which took $n$ as an argument and returned $\sum_k {n \choose 3k}$. The verb was the following: a =: [:+/(3*i.)!] But if you try to pass it not a single $n$ but a list, the verb doesn't work. Which is a shame because the intended use was to examine the series. And so I started searching for something akin to Haskell's `map`. After half an hour of sifting through J tutorials that expressed delight in the fact that J lifts operations to arrays of arbitrary ranks by default and therefore doesn't need `map`, I've finally found what I was looking for, namely `a "0 i.50`, the rank operator, and it turned out that `map` isn't magic after all and is just a single case of a more general operation. I hadn't seen the rank operator in any language before and was thrilled to feel the potential that this operator holds. So the language is great, and it seems that common use cases are handled by elegant general solutions, that is, the language is designed to be mostly free from corner cases. That's why the unintuitive handling of 0x1 seems to me especially weird. I could ignore it if Python did it, if C++ did it, but J simply doesn't look like a language that intoduces inconsistencies for no reason. So it is highly probable that it's me who doesn't understand higher purpose of the construct. And so I came here hoping that someone explains it to me. The J community has a reputation of being tolerant to uninsightful questions of beginners. </information irrelevant to the question> Sorry if my English has some mistakes or is in the wrong tone. The reason isn't negligence, it's just that English isn't my native language. Regards, Dmitry Khalansky. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
