Agree with most of this, would only make two notes: 1)
Things like += are most likely to be applied to true local variables, so locatives are irrelevant and the differences between =: and =. are relevant (the primary purpose of my response to your modf was to point this out) 2) I like your tacit/explicit hybrid code and it has a some advantages over the hybrid that I posted. Now, I don't think it would be common for f to be multi-line: the likely use case is that f is trivial, as in + (because += et al are used to make a common, trivial, operation on temp vars more convenient). Furthermore, the longer and more complex f is, the less value modf is adding (ie the less difference there is between f = f u y and f u= y). And, again, the use of modf is likely within expl def, so it's very unlikely that f is an anonymous multi-line verb (and of course any named verb can always fit on one line). All that said, I appreciate the value of a general solution, and also the difficulties of applying 5!:5 to multiline verbs (and while it would be better to use 5!:6, the same difficulties would remain). But note that half the difficulty is due to the fact that we need a single line definition in the first place, which is a restriction of ". . To that point, we could use 0!: instead, which is like ". but accepts arbitrary J scripts (and we might use 5!:7 to produce these scripts, where appropriate). -Dan Please excuse typos; composed on a handheld device. -----Original Message----- From: Raul Miller <rauldmil...@gmail.com> Date: Wed, 21 Apr 2010 14:18:11 To: Programming forum<programming@jsoftware.com> Subject: Re: [Jprogramming] f += 1 On Wed, Apr 21, 2010 at 1:05 PM, Dan Bron <j...@bron.us> wrote: > IOW, normally what's wanted is f=.f+1 (not =:), of course explicit > definitions cannot manipulate the local names within other explicit > definitions. Note that =: and =. are equivalent for locatives, and large code bodies should probably be using locatives in appropriate locales. That said, here is a variation which uses =. instead of =: linrep=:3 :'5!:5<''y''' modfl=:1 :0 [ ".@, '=.', [,' ',m,lin...@] ) This version requires the verb to be quoted. I did that because 5!:5 does not do anything useful for me, with multi-line verbs. -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
