RPL equivalents to BREAK, CYCLE, EXIT, etc.?

[Thomas Klemm]

(06-09-2014 04:24 PM)DavidM Wrote:  Before I even responded to Thomas, I realized that he intentionally chose an example that was biased toward using something like a BREAK.

My intention was to provide an example where eliminating the BREAK isn't trivial. I knew you couldn't use the FOR-loop and then you had to find a way to access the outcome of hasDivisor outside the loop. Throwing an error allows to pass that information without using a local variable.

I guess the most difficult part in my program is to figure out the next step after DROP:

Code:

    NEXT DROP
  THEN 0
  ELSE 1

In a longer program this can be multiple lines away from the condition.

And I agree with you: reasoning about a program is more difficult if there are multiple exit points.
I like your solution: By using meaningful names for the variables the intent is made clear.

Let me add a 3rd more functional variant:

Code:

\<< \-> n
  \<<
    'n MOD ?' ? 2 n \v/ 1 SEQ
    \<< AND \>> STREAM
  \>>
\>>

It doesn't work for small numbers and it doesn't short-cut when the first factor is found. But if the sequence was evaluated lazy the calculator could do that for us.

Kind regards
Thomas