[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [gforth] words backwards
From: |
Bernd Paysan |
Subject: |
Re: [gforth] words backwards |
Date: |
Fri, 19 May 2017 18:24:13 +0200 |
Am Freitag, 19. Mai 2017, 18:09:30 CEST schrieb Dennis Ruffer:
> Since Forth dictionaries are typically, singly linked lists, it would take
> memory and time to reverse the order.
Yes, but on a desktop system, we actually have that memory. And time is even
less important. This does it, by converting the list into an array and then
stepping backwards through that array:
Variable words[]
: words ( -- )
[: words[] dup $[]# swap $[] ! true ;] context @ traverse-wordlist
source nip 1+ words[] $@ bounds cell- swap cell- U-DO
I @ .word
cell -LOOP drop
words[] $free ;
Works in the current development system.
--
Bernd Paysan
"If you want it done right, you have to do it yourself"
net2o ID: kQusJzA;address@hidden(dQ*
http://bernd-paysan.de/