There are free and trial APLs but this is not the appropriate forum for such discussion. Perhaps post in chat or comp.lang.apl.
Note that J does have a goto, see http://jsoftware .com/docs/help801/dictionary/cgoto.htm. Line numbers are just formatting, and that can be approximated in any editor by setting on line numbers. In any case, these should be minor issues in the total scheme of things. On Fri, Apr 4, 2014 at 11:00 AM, <rhb...@asis.com> wrote: > Hello: > > I programmed APL in college. > > Is there a free version out there? > > I have J on my desktop, but can't get my head around no line numbers, and > gotos. > > Yours, Bob. > > > > > Quoting Raul Miller <rauldmil...@gmail.com>: > > On Thu, Apr 3, 2014 at 6:19 PM, Omar Antolín Camarena < >> omar.anto...@gmail.com> wrote: >> >> fn =: 1 : '(2 2 1 1 4 3 3 {~ 1 i.~ (_1 <\ ''vnumxy'') e. ;: m) : m' >>> >>> >> That's clever thinking. >> >> >> 1. In APL's with this {} syntax, can you force a function whose source >>> code >>> only mentions omega to be dyadic? I.e., in J I can do 3 : 'y*y', but >>> also 4 >>> : 'y*y'. >>> >>> >> Here's how you can do that the fn way: >> >> 'y * y return. x' fn >> >> >> 2. Beyond these what are the advantages and disadvantages of J's and >>> APL's >>> {} way of dealing with explicit definition? >>> >>> >> J's way lets you define both monadic and dyadic definitions together. >> >> And, on a related note, the way you have defined fn, adverbs (and >> conjunction) can only produce monadic verbs. You do not support things >> like >> this: >> >> combiner=:1 :0 >> : >> x,m,y >> ) >> >> 3. Why does J require you to specify the left argument to :? Is it for the >> >>> reason in question 1? >>> >>> >> J allows two different kinds of left arguments for : >> >> A numeric left argument controls the type of explicit definition being >> generated. >> >> But you can also combine two verbs. Consider, for example: >> >> ('-y' fn) : ('x-y' fn) >> >> That's a long-winded way of expressing subtraction, but the point is that >> both monadic and dyadic definitions are supported. >> >> 10 '-y' fn : ('x-y' fn) 3 >> 7 >> '-y' fn : ('x-y' fn) 3 >> _3 >> >> 4. Is there a better name for this adverb than fn? >> >>> >>> >> We could call it George, if you like? >> >> >> 5. What would be a more robust rule for picking the type of the resulting >>> operator? I mean, presumably 'u * x i. u=. ~. y' (ignore the random >>> nonsense) is meant to be a dyadic verb even though it contains a u. I >>> guess >>> one could only count references to u if u never occurs as the target of a >>> copula or something like that. (I don't think this problem arises in APL, >>> because I don't think assignments to alphalpha are allowed, but I might >>> be >>> wrong.) >>> >> >> >> Hopefully my answers to your question 1 and 2 shed some light on this >> issue. >> >> Thanks, >> >> -- >> Raul >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program. > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
