From 824a4be938c62e1254237eef0315d9248ab68dc5 Mon Sep 17 00:00:00 2001
From: Tim Vaughan <tgvaughan@gmail.com>
Date: Wed, 1 Jun 2016 21:32:48 +1200
Subject: [PATCH] Added CMOVE>

---
 src/forth.jl          |  2 +-
 src/lib_5_strings.4th | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/forth.jl b/src/forth.jl
index c5c7175..5730c38 100644
--- a/src/forth.jl
+++ b/src/forth.jl
@@ -899,7 +899,7 @@ DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
     end)), name="doesPrim")
 
     return NEXT
-end, flags=F_IMMED)
+end, flags=F_IMMED | F_HIDDEN)
 
 DOES_CFA = defWord("DOES>",
     [LIT_CFA, LIT_CFA, COMMA_CFA, HERE_CFA, LIT_CFA, 3, ADD_CFA, COMMA_CFA,
diff --git a/src/lib_5_strings.4th b/src/lib_5_strings.4th
index 99d1d39..9fef145 100644
--- a/src/lib_5_strings.4th
+++ b/src/lib_5_strings.4th
@@ -3,6 +3,7 @@
 : CMOVE ( src dest length -- )
 
         DUP 0<= IF
+                DROP DROP DROP
                 EXIT
         THEN
 
@@ -18,6 +19,24 @@
         DROP
 ;
 
+: CMOVE> ( src dest length -- )
+        DUP 0<= IF
+                DROP DROP DROP
+                EXIT
+        THEN
+
+        -ROT OVER -         ( length src (dest-src) )
+        -ROT DUP ROT + 1-   ( (dest-src) src (src+length-1) )
+        
+        DO
+                I @
+                OVER I +
+                !
+        -1 +LOOP
+
+        DROP
+;
+
 : S" IMMEDIATE          ( -- addr len )
         STATE @ IF      ( compiling? )
                 ['] LITSTRING ,   ( compile LITSTRING )
-- 
2.20.1