markov chain module

MarkovBot/MarkovChain.pm

@@ -0,0 +1,40 @@
+package MarkovBot::MarkovChain;
+use base qw(Exporter);
+use 5.010;
+use strict;
+use warnings;
+
+our @EXPORT = qw(markov);
+
+use FindBin qw($Bin);
+use lib $Bin;
+
+use MarkovBot::Config;
+use MarkovBot::Redis;
+
+sub markov( $ ) {
+  # markov - given two starting words, returns a markov chain result
+
+  my $redis = redis;
+  my $p = config "redis_prefix";
+  my $s = shift;
+  my @s = @{$s};
+
+  if (!$redis->llen("$p:chains:$s[0],$s[1]")) {
+    # Phrase is not known
+    return undef;
+  }
+
+  while (1) {
+    # get next word
+    my $len = $redis->llen("$p:chains:$s[$#s-1],$s[$#s]");
+    my $pos = int(rand($len));
+    push @s, $redis->lrange("$p:chains:$s[$#s-1],$s[$#s]", $pos, $pos);
+    last if $s[$#s] eq "___end___";
+  }
+
+  pop @s;
+  return join " ", @s;
+}
+
+1;