From e82947d00f700558500e85e22aaf187544769a2e Mon Sep 17 00:00:00 2001
From: Chouser <chouser@n01se.net>
Date: Tue, 17 Feb 2015 09:40:03 -0500
Subject: forth: Add step 8

---
 forth/core.fs | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

(limited to 'forth/core.fs')

diff --git a/forth/core.fs b/forth/core.fs
index e601e1d..43e6b75 100644
--- a/forth/core.fs
+++ b/forth/core.fs
@@ -96,3 +96,21 @@ defcore concat { lists argc }
     MalList new
     start over MalList/start !
     count over MalList/count ! ;;
+
+defcore nth ( argv[coll,i] argc )
+    over ( argv argc argv )
+    cell+ @ MalInt/int @ ( argv argc count )
+    swap over <= if ." nth out of bounds" cr 1 throw endif ( argv count )
+    cells swap ( c-offset argv )
+    @ to-list MalList/start @ + @ ;;
+
+defcore first ( argv[coll] argc )
+    drop @ to-list
+    dup MalList/count @ 0= if
+        drop mal-nil
+    else
+        MalList/start @ @
+    endif ;;
+
+defcore rest ( argv[coll] argc )
+    drop @ to-list MalList/rest ;;
-- 
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