From c314cb727fdccf726290ee0ff0bc0478d737365f Mon Sep 17 00:00:00 2001
From: Eduardo Cavazos <dharmatech@finkelstein.stackeffects.info>
Date: Wed, 16 Jul 2008 22:10:09 -0500
Subject: [PATCH] display-stack: stack display with support for watched
 variables

---
 extra/display-stack/display-stack.factor | 41 ++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 extra/display-stack/display-stack.factor

diff --git a/extra/display-stack/display-stack.factor b/extra/display-stack/display-stack.factor
new file mode 100644
index 0000000000..161cd6760d
--- /dev/null
+++ b/extra/display-stack/display-stack.factor
@@ -0,0 +1,41 @@
+
+USING: kernel namespaces sequences math
+       listener io prettyprint sequences.lib fry ;
+
+IN: display-stack
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+SYMBOL: watched-variables
+
+: watch-var ( sym -- ) watched-variables get push ;
+
+: watch-vars ( sym -- ) watched-variables get [ push ] curry each ;
+
+: unwatch-var ( sym -- ) watched-variables get delete ;
+
+: print-watched-variables ( -- )
+  watched-variables get length 0 >
+    [
+      "----------" print
+      watched-variables get
+        watched-variables get [ unparse ] map longest length 2 +
+        '[ [ unparse ": " append , 32 pad-right write ] [ get . ] bi ]
+      each
+
+    ]
+  when ;
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+: display-stack ( -- )
+  V{ } clone watched-variables set
+    [
+      print-watched-variables
+      "----------" print
+      .s
+      "----------" print
+      retainstack reverse stack.
+    ]
+  listener-hook set ;
+