(Despite the conversations that have brought us to this point -- and
ignoring that scenario altogether) I have a hypothesis that for the
long-term, a team equipped in a J-focused environment needs to have a very
detailed design-time road map to avoid a possible scenario in its project
whereby re-designing one aspect has a negative and significant impact on
unrelated aspects of the project. For our team, we had become interested
in J because of highly regarded recommendations about its fit into an XP
environment. At the same time, it appears that folks are suggesting that
design decisions are required to be made earlier (moreso comparable to the
waterfall paradigm). And this is important to the long-term maintainability
(in terms of cost and time) of the project.
For example, when considering a function (or function group) and choosing
the tacit implementation, I have been advised from 2 (seemingly?)
incompatible perspectives.
One one hand, it is my understanding that one of the primary advantages to a
tacit design is the ability to abstract a dependency on names. On the other
hand, I understand that, in an ambivalent function, such is not the case.
That, unfortunately, this won't work for the dyadic half, since it could
not distinguish between local x and global x, as x is defined locally in
both the verb and the adverb.
And when I look at some implementations, I see that this appears to be the
case.
NB.*nl v selective namelist
NB. Form: [mp] nl sel
NB.
NB. sel: one or more integer name classes, or a name list.
NB. if empty use: 0 1 2 3.
NB. mp: optional matching pattern. If mp contains '*', list names
NB. containing mp, otherwise list names starting mp. If mp
NB. contains '~', list names that do not match.
NB.
NB. e.g. 'f' nl 3 - list verbs that begin with 'f'
NB. '*com nl '' - list names containing 'com'
nl1=.(([:4!:1])&(]`(0 1 2 3"_)@.(0=#))) :: cutopen_*z*_
nlz=:(nl1 : ((4 : 0)nl1)) f.
if. 0 e. #y do. y return. end.
if. #t=. x -. ' ' do.
'n s'=. '~*' e. t
t=. t -. '~*'
b=. t&E. &> y
if. s do. b=. +./"1 b
else. b=. {."1 b end.
y=. y #~ n ~: b
end.
)
I see that (on the dyad side of the picture) there is still reference to
local x. But, this should not be an issue, should it? Since we could go
ahead and reference x__anotherlocale. In my prima facie testing, I don't
notice the issue. Tests which had failed in previous tests, pass with this
example.
I realize that the road ahead is a long one to become proficient at
recognizing some of the subtleties that, presently, have us perplexed.
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