You cannot always break down j as shown. digits is the proverb for a
hook. In the hook, "."0 is the dyadic numbers. The original sentence
evaluates "."0 as the monad do at rank 0. digits happens to work
because the digits from formatting a number are necessarily valid.
Literal data distinguishes these:
digits=:"."0 ":
"."0 ": '123'
1 2 3
digits '123'
|domain error: digits
| digits'123'
>Date: Wed, 28 May 2014 23:48:31 +0800
>From: Rob Hodgkinson <[email protected]>
>To: [email protected]
>Subject: Re: [Jprogramming] Project Euler 16, J vs Haskell
>Message-ID: <[email protected]>
>Content-Type: text/plain; charset=windows-1252
>
>Jon, a brief note on your point re readability ? you can always break
J down as follows if you require;
>
> +/ "."0 ": !100x NB. From Roger
>648
>
> sum=:+/
> digits=:"."0 ":
> factorial=:!
> sum digits factorial 100x
>648
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
