/hello Don; The difference I see between tacit and explicit is that the former results in verb-valued expressions, and the latter in noun-valued ones. Integrating these two seems almost hopeless.
Don Watson wrote: > Hi Tracy, > > Thanks. Much of my problem is not so much learning J as learning the > jargon that describes J. I will debate the following issues: > > You said: > > "When parentheses are needed to isolate an expression from something > that would otherwise be parsed as a parameter, they therefore also > delimit where an argument may be found." > > I agree that this is presently the case. I am not taking away anything > from that situation. However, I am asking you to consider the two > "things" separately, so that, while regular parentheses carry out both, > something else, like a right parenthesis, can only delimit where the > argument is found. > > You said: > > "Your understanding of the differences between explicit and tacit > phrasing is clearly advancing. I share your wish that J were easier to > learn than it is . . ." > > You are right. As I first met J, I was certain that something was > missing, but did not know what it was. I have tried several approaches > and gradually used them to close in on what is missing. At this point, > I see the problem as coming not from tacit J itself, but from the > interface between tacit and explicit J. > > The inability to separate the boundary between the two from the > identification of arguments is a problem. It also does not help that > tacit J has one way of defining new verbs and explicit J has another. > > I believe it is possible clarify the interface between tacit J and > explicit J in such as way that the two forms intermingle into a single > form and tacit J can be used where its strengths are needed and > explicit J where it provides a neater solution. > > Maybe inside-out parentheses are the wrong choice, but some > other delimiter on the range of the search for tacit J arguments > would really help the integration. > > Don > > ----- Original Message ----- > From: "Tracy Harms" <[email protected]> > To: "Chat forum" <[email protected]> > Sent: Tuesday, May 19, 2009 10:13 AM > Subject: Re: [Jchat] Transition > > > On Tue, May 19, 2009 at 5:01 AM, Don Watson <[email protected]> wrote: > >> ... the outer parentheses >> cause J to treat all contents between these parentheses as a train of >> forks and hooks instead of right to left J code. To compensate, we need >> "@:" and "[:" conjunctions. >> >> ([: %: +/@:*:@:(- +/ % #) % <:@#) 2 4 9 6 >> 2.98608 >> >> The parentheses around the whole expression do two things: >> >> 1) They define the where the argument for the tacit expression (- +/ % #) >> is to be found. >> 2) They define the content within the parentheses to be a train of forks >> and hooks. >> >> > > Hi, Don. > > What you have here called two things are actually one and the same > thing. A tacit expression is one in which no parameters are explicit. > When parentheses are needed to isolate an expression from something > that would otherwise be parsed as a parameter, they therefore also > delimit where an argument may be found. > > Your understanding of the differences between explicit and tacit > phrasing is clearly advancing. I share your wish that J were easier to > learn than it is, but I don't share your confidence that what it has > to offer can be made more approachable by changing syntax. In my view, > J syntax is so simple that it can't be bent without breaking. The > opportunity I see is in finding creative ways to communicate J so that > learning it can be easier. Changes that are as deep as you're > proposing produce problems of language design, which are much harder > still. > > Tracy > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > > -- ------------------------------------------------------------------------ |\/| Randy A MacDonald | APL: If you can say it, it's done.. (ram) |/\| ramacd <at> nbnet.nb.ca | |\ | | The only real problem with APL is that BSc(Math) UNBF'83 | it is "still ahead of its time." Sapere Aude | - Morten Kromberg Natural Born APL'er | -----------------------------------------------------(INTP)----{ gnat }- ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
