From 7a2be16d77bdf274d8f21a0f3590053abb7e49ac Mon Sep 17 00:00:00 2001
From: Lars Brinkhoff <lars@nocrew.org>
Date: Tue, 30 Sep 2014 07:01:35 +0200
Subject: [PATCH] Add .frt samples for Forth.

---
 samples/Forth/bitmap.frt | 8 ++++++++
 samples/Forth/enum.frt   | 7 +++++++
 samples/Forth/macros.frt | 8 ++++++++
 3 files changed, 23 insertions(+)
 create mode 100644 samples/Forth/bitmap.frt
 create mode 100644 samples/Forth/enum.frt
 create mode 100644 samples/Forth/macros.frt

diff --git a/samples/Forth/bitmap.frt b/samples/Forth/bitmap.frt
new file mode 100644
index 00000000..c3ee6c39
--- /dev/null
+++ b/samples/Forth/bitmap.frt
@@ -0,0 +1,8 @@
+\ Bit arrays.
+: bits ( u1 -- u2 ) 7 + 3 rshift ;
+: bitmap ( u "name" -- ) create bits here over erase allot
+   does> ( u -- a x ) over 3 rshift +  1 rot 7 and lshift ;
+: bit@ ( a x -- f ) swap c@ and ;
+: 1bit ( a x -- ) over c@ or swap c! ;
+: 0bit ( a x -- ) invert over c@ and swap c! ;
+: bit! ( f a x -- ) rot if 1bit else 0bit then ;
diff --git a/samples/Forth/enum.frt b/samples/Forth/enum.frt
new file mode 100644
index 00000000..f7cc30ab
--- /dev/null
+++ b/samples/Forth/enum.frt
@@ -0,0 +1,7 @@
+\ Implements ENUM.
+
+\ Double DOES>!
+: enum   create 0 ,  does> create dup @ 1 rot +! ,  does> @ ;
+
+\ But this is simpler.
+: enum   create 0 ,  does> dup @ constant 1 swap +! ;
diff --git a/samples/Forth/macros.frt b/samples/Forth/macros.frt
new file mode 100644
index 00000000..e3a205b7
--- /dev/null
+++ b/samples/Forth/macros.frt
@@ -0,0 +1,8 @@
+\ Simplifies compiling words.
+
+: [[     ; immediate
+: '<>    >in @ ' swap >in ! <> ;
+: (]])   begin dup '<> while postpone postpone repeat drop ;
+: ]]     ['] [[ (]]) ; immediate
+
+( Usage:   : foo ]] dup * [[ ; immediate   : bar 42 foo . ; )