HHC 2016 RPL Programming Contest

[3298]

(09-21-2016 12:10 AM)DavidM Wrote:  I made an attempt to translate this same algorithm to a SysRPL implementation, but the smallest I could achieve was still slightly larger than 3298's at 42.5 bytes:

Nosy gave me a handy routine you could use to get your size down to mine. At 13FD8 there is this small secondary;

Code:

:: ONE POSCHR ;

It's apparently unnamed, so I cannot guarantee that it's present on all ROM versions, but I'd expect most people are running 2.15 by now, which is the version I found this on. So replace the two commands ONE POSCHR by the single command PTR 13FD8 and enjoy a 40-byte solution! As a bonus, you have the same option to reduce its size further at the cost of usability (removing the UNCOERCE).

(09-21-2016 12:10 AM)DavidM Wrote:  ...and with apologies to 3298

What for? I posted code on a public forum without any copyright notice, so it's meant to be read, understood, used, and modified. This wasn't quite the kind of modification I expected (that would have been some more size optimization), but it's perfectly fine. Such a little snippet isn't worth putting a copyright on anyway. You even beat my own UserRPL translation by several commands.

About NIP: I think that's a Forth thing. As that's another important language in reverse polish notation, it's kind of expected RPL borrows some Forth concepts. Another example: The Forth equivalent of a FOR...NEXT is DO...LOOP, and in SysRPL they are - surprise! - written as DO...LOOP. Or even more basic, a Forth program is delimited by colon and semicolon. SysRPL just doubles the colon, possibly because on RPL.machines you usually get colons in pairs (for tagged objects).