[Jprogramming] monad vs. dyad

[Roger Hui]

Cute.  142857 is immediately recognizable to me as
the decimal expansion of %7 .

1. The dyad =/ is the function table for = .
The monad =/ inserts = between items of the
argument.  Thus =/1 4 2 8 5 7 is 1=4=2=8=5=7 which,
because of the right-to-left evaluation and because
x=y is 0 or 1, does not mean the same as it does
in conventional math notation.

2. The left-hand-side of assignment must be a name
or a string satisfying certain conditions.

4. The "capped fork" [: f g is the same as f@:g .

3. Yes, for example:
   >: ^: (1 < [: #@~. [: /:~@":"0 (>:i.6) * ]) ^: _ ] 1
142857

f^:proposition^:_ y is a common construct, meaning
 z=. y
 while. proposition y do. z=. f z end.



----- Original Message -----
From: Geoff Canyon <geoffc at inspiredlogic.com>
Date: Tuesday, March 20, 2007 1:15 am
Subject: Re: [Jprogramming] monad vs. dyad

> Thanks for the help!
> 
> 0 is the obvious answer, but there are other numbers that meet 
> this  
> criteria.
> 
> I modified your code like this:
> 
>    f=:((1<])#@:~.@:(/:~@:":"0)@:((>:i.6)*]))+]
>    (f^:_) 1
> 
> And got my answer. This leaves me with the following questions:
> 
> 1. So what _does_ =/ mean?
> 2. If it doesn't mean anything, is it possible for me (any user) 
> to  
> define =/=:1&=#]  ? (apparently not)
> 3. Is there a way to compose my two lines above into a single command?
> 4. To avoid all the @: above, should I be looking for ways to turn 
> it  
> into forks and/or hooks?
> 
> I have to add: my brain hurts! (in a good way)