From 2cacc7bc792a06f3ba716a980a9d5992e475140f Mon Sep 17 00:00:00 2001
From: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Date: Sun, 29 Jul 2007 00:24:13 +0200
Subject: [PATCH] Methods to get a previous word

---
 mark2.rb | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/mark2.rb b/mark2.rb
index 779c746..ab3c38b 100644
--- a/mark2.rb
+++ b/mark2.rb
@@ -196,5 +196,24 @@ class MarkovChainer
     raw_next(syms)
   end
 
+  def raw_prev(syms)
+    ar = syms.first([MAX_ORDER, syms.size].min)
+    ord = ar.size
+    if ord == 0
+      @mkv[0].random
+    else
+      if @mkv[ord].key?(ar)
+        @mkv[ord][ar][:prev].random
+      else
+        raw_next(ar.first(ord-1))
+      end
+    end
+  end
+
+  def prev(text)
+    syms = text.scan(WNW).map { |w| w.intern }
+    raw_prev(syms)
+  end
+
 end
 
-- 
2.32.0.93.g670b81a890