It seems to be so. Maybe this is said in Learning J, but if it isn't, please someone tell Roger Stokes to add the explanation of this feature to his excellent book.
----- Original Message ----- From: "Kip Murray" <[email protected]> To: "Programming forum" <[email protected]> Sent: Friday, November 04, 2011 11:32 AM Subject: Re: [Jprogramming] Newbie question >I believe it is correct that a fork has rank _ . You can experiment > using b. as shown below: > > (+ * -) b. 0 > _ _ _ > + b. 0 > 0 0 0 > * b. 0 > 0 0 0 > - b. 0 > 0 0 0 > > (The ranks of the verb on the left are given in the order monadic left > right.) > > > On 11/4/2011 5:30 AM, Ricardo Forno wrote: >> The thing that confused me is that I didn't know a fork has rank _ as >> Marshall wrote. Is that correct? Browsing through Learning J, I couldn't >> find if this fact is mentioned there. >> >> ----- Original Message ----- >> From: "Henry Rich"<[email protected]> >> To: "Programming forum"<[email protected]> >> Sent: Friday, November 04, 2011 7:15 AM >> Subject: Re: [Jprogramming] Newbie question >> >> >>> Just a quibble with terminology: 'item' means _1-cell. That concept >>> does not apply here. If you define 'l-cell' to be the left rank of the >>> verb, and 'r-cell' the right rank, you could say >>> >>> ...it loops through all the l-cells of x, then for each of those, all >>> the r-cells of y... >>> >>> Henry Rich >>> >>> On 11/4/2011 12:13 AM, Marshall Lochbaum wrote: >>>> * has rank 0 already, so it isn't necessary. The definition of / is >>>> that >>>> it >>>> applies the verb with rank (left rank),_ . Essentially, this means that >>>> it >>>> loops through all the items of x, then for each of those, all the items >>>> of >>>> y, where an "item" is an item with the left rank of the verb. If you >>>> try >>>> magic/~ a with magic having rank _ (because it's a fork), you just get >>>> (a >>>> magic"_ _"_ _ a), which simply applies magic regularly. >>>> >>>> Marshall >>>> >>>> On Thu, Nov 3, 2011 at 11:57 PM, Ricardo >>>> Forno<[email protected]>wrote: >>>> >>>>> I have this verb: >>>>> magic =: * %>:@(+:@*) - + >>>>> that I use only as a dyad, and, say, >>>>> a =: 0.1 * i. 10 >>>>> If I want to get a table of the * verb, I write: >>>>> a * / a >>>>> If I write >>>>> a magic / a >>>>> I dont get a table. To get a table, I have to write: >>>>> a magic"0 / a >>>>> Why is it so, since both * and magic may be used as dyads? >>>>> Thanks. >>>>> >>>>> >>>>> ---------------------------------------------------------------------- >>>>> For information about J forums see http://www.jsoftware.com/forums.htm >>>>> >>>> ---------------------------------------------------------------------- >>>> For information about J forums see http://www.jsoftware.com/forums.htm >>>> >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >>> >> >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
