List Commands Library for 50g

[John Keith]

(05-22-2018 02:01 PM)DavidM Wrote:  Would you be able to elaborate on what you mean by "numeric sequences where the next element is a function of two or more previous elements"? Applying functions to list elements is a central theme to many GoferLists commands, so I've mostly stayed away from that sort of thing with ListExt. What's an example of what you have in mind for this?

I think "function" was an ambiguous word here. I was referring to Fibonacci-like sequences with additional levels of abstraction. In these sequences, the next element in the series can be the sum of two or more elements arbitrarily far back in the sequence, not just the last two. The expressions involved are simple one-liners in e.g. the Prime Sequence app but simple RPL programs for them would be very slow once the list size grew to 50 or so. To make a reasonably fast RPL program requires a lot of stack gymnastics that make the program hard to write and impossible to read.

I'm sure the preceding paragraph is clear as mud but I'm not at home now and I don't have my notes with me. Basically it amounts to the well-known problem with RPL that building lists by appending one element at a time is much slower than doing the work on the stack and collecting everything into a list at the end. I'm guessing that if there was a simple fix for this it would have been found by now but hope springs eternal...

John