| Mike Kent 2005-04-27, 3:56 pm |
| James J. Weinkam wrote:
> Björn Helgason wrote:
....
> First of all what in heavens name is =:? Some languages use = for
> assignment,
> some use :=, but what is =:?
>
> OK, I'll jump to the conclusion (based on the structure of your sequence of
> whatever they are, lines, statements, assertions, declarations,
> expressions,
> utterances, you come up with more possibilities) that =: means "is
> defined to
> be" similar to ::= in BNF.
>
> sum=:+/ This is familiar from APL (presumably the APL content)
>
> what=:'5' sum what seems to say that the thing to be summed is 5
>
> equal=:= equal is defined to be =, can't argue with that
>
> format=:": format is defined to be ": This explains a lot
>
> numbers=:i.100 Ditto. Hard to decide which of the last two lines is more
> illuminating.
>
> sum what equal format numbers
> 20
>
> So you summed 4 5's Where did the 4 come from?
I think he summed 20 1's; see below.
>
> Sorry for the somewhat sharp style of this post, but in my opinion a
> newsgroup
> posting should be designed to illuminate and instruct. The linguae
> francae of
> this news group are English for prose and APL for programming. If you
> are going
> to explain to APL'ers what +/'5'=":i.100 means that might be useful, but
> do it
> in English and/or APL or define your notation in those terms so that it
> is not a
> message only for insiders from some other world.
Clearly
+/'5'=":i.100
translates to
+/ '5' = {format} {iota} 100
20
(given that Bjorn said ": is 'format' and guessing that
iota =: i. }
IMO ... J orthography is, well, ummm, aah, sorry, but it's u g l y .
I wouldn't have thought that i. isn't one of the hard ones (for APLers)
to figure out, though.
|