Randy MacDonald wrote (Jan. 5):
> Happy New Year Neville;
Thank you, and the same to you !
> Is it possible to provide some examples?
I'll try some below, but first . . .
> (f g ].) NB. what, if anything, would this mean?
I would expect z =. f g ]. would mean the same
as z =. 2 : 'f g v' so that + z * would give the
fork f g * assuming f and g were verbs; in other
words, z would in use require two operands
even though the left operand is not used.
The first and simple example I gave earlier was
z =. ] ,: [. where *: z i.5 would stack the right
argument over its square. Raul Miller pointed
that this could be done by *: ^: 0 1 which is
certainly simpler. But for dyadic functions I
would like z =. [ , ] ,: [. which would stack both
arguments over their dyadic result, like
a ^ z b would stack a over b over a^b.
Another example I gave was z =. ].~ [. ]. which
would be equivalent to 2 : 'v~ u v' and a ^ z <. b
would yield the lower of a^~b and a^b.
What this amounts to is the freedom to drop one
or two functions freely into a functional expression,
and not just as an item in a train, in much the same
way that [ and ] can bring arguments into a tacit
expression.
My need, as I have explained earlier, is a pedagogical
one, and I don't have enough recent experience to
be able to resolve the issues that Raul has raised.
One of these is whether an operand to a tacitly defined
operation can be other than a verb, as can operands
to primitive operations like & and ^:. I would have
liked this possibility, but it isn't essential as there
are ways around it.
Another issue is the question of when [. and ]. are
substituted for. For example, in ]. + ([. -) I think the
+ shouldn't replace the [. but this might be one of
parsing problems that Raul was raising. I guess I'd
like [. and ]. as free as possible in use, even unto
being able to bring two nouns in as operands, but
this would need to be done with as little disturbance
as possible to J's present syntax and semantics.
I wish I could give you a more considered resume
and more examples, but we have just found out
(while I was in the middle of this message) that
we have managed to sell our house and have 30 days
now to shift to a house we've bought on the mainland.
This will now loom large in my foreground and so
J (and lots else) will shift to the background for a while.
Neville Holmes, P.O.Box 404, Mowbray 7248, Tasmania
Normal e-mail: [EMAIL PROTECTED]
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