From: Tim Vaughan <tgvaughan@gmail.com>
Date: Tue, 26 Apr 2016 21:01:56 +0000 (+1200)
Subject: Finished ROLL
X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=forth.jl.git;a=commitdiff_plain;h=d2ce0337817800a06106ecc4943f10106739cf8b

Finished ROLL
---

diff --git a/src/lib.4th b/src/lib.4th
index 781a966..f4b28e6 100644
--- a/src/lib.4th
+++ b/src/lib.4th
@@ -170,10 +170,6 @@
         @               ( and fetch )
 ;
 
-: ROLL ( x_u x_u-1... x_0 u -- x_u-1 ... x_0 x_u )
-        1+ DUP PICK SWAP    ( x_u x_u-1 ... x_0 x_u u+1 )
-;
-
 ( With the looping constructs, we can now write SPACES, which writes n spaces to stdout. )
 : SPACES        ( n -- )
         0 DO
@@ -316,3 +312,13 @@
         THEN
 ;
 
+: ROLL ( x_u x_u-1... x_0 u -- x_u-1 ... x_0 x_u )
+        1+ DUP PICK SWAP    ( x_u x_u-1 ... x_0 x_u u+1 )
+        PSP@ 1- SWAP - PSP@ 2- SWAP
+        DO
+            i 1+ @ i !
+        LOOP
+        SWAP DROP
+;
+
+