1 files changed, 122 insertions, 0 deletions
diff --git a/rbot/plugins/math.rb b/rbot/plugins/math.rb
new file mode 100644
index 00000000..4a207389
--- /dev/null
+++ b/rbot/plugins/math.rb
@@ -0,0 +1,122 @@
+class MathPlugin < Plugin
+  @@digits = {
+     "first" => "1",
+     "second" => "2",
+     "third" => "3",
+     "fourth" => "4",
+     "fifth" => "5",
+     "sixth" => "6",
+     "seventh" => "7",
+     "eighth" => "8",
+     "ninth" => "9",
+     "tenth" => "10",
+     "one" => "1",
+     "two" => "2",
+     "three" => "3",
+     "four" => "4",
+     "five" => "5",
+     "six" => "6",
+     "seven" => "7",
+     "eight" => "8",
+     "nine" => "9",
+     "ten" => "10"
+  };
+
+  def help(plugin, topic="")
+    "math <expression>, evaluate mathematical expression"
+  end
+  def privmsg(m)
+    unless(m.params)
+      m.reply "incorrect usage: " + help(m.plugin)
+      return
+    end
+
+    expr = m.params.dup
+    @@digits.each {|k,v|
+      expr.gsub!(/\b#{k}\b/, v)
+    }
+
+    while expr =~ /(exp ([\w\d]+))/
+      exp = $1
+      val = Math.exp($2).to_s
+      expr.gsub!(/#{Regexp.escape exp}/, "+#{val}")
+    end
+    
+    while expr =~ /^\s*(dec2hex\s*(\d+))\s*\?*/
+      exp = $1
+      val = sprintf("%x", $2)
+      expr.gsub!(/#{Regexp.escape exp}/, "+#{val}")
+    end
+
+    expr.gsub(/\be\b/, Math.exp(1).to_s)
+
+    while expr =~ /(log\s*((\d+\.?\d*)|\d*\.?\d+))\s*/
+      exp = $1
+      res = $2
+      
+      if res == 0
+        val = "Infinity"
+      else
+        val = Math.log(res).to_s
+      end
+      
+      expr.gsub!(/#{Regexp.escape exp}/, "+#{val}")
+    end
+
+    while expr =~ /(bin2dec ([01]+))/
+      exp = $1
+      val = join('', unpack('B*', pack('N', $2)))
+      val.gsub!(/^0+/, "")
+      expr.gsub!(/#{Regexp.escape exp}/, "+#{val}")
+    end
+
+    expr.gsub!(/ to the power of /, " ** ")
+    expr.gsub!(/ to the /, " ** ")
+    expr.gsub!(/\btimes\b/, "*")
+    expr.gsub!(/\bdiv(ided by)? /, "/ ")
+    expr.gsub!(/\bover /, "/ ")
+    expr.gsub!(/\bsquared/, "**2 ")
+    expr.gsub!(/\bcubed/, "**3 ")
+    expr.gsub!(/\bto\s+(\d+)(r?st|nd|rd|th)?( power)?/, "**\1 ")
+    expr.gsub!(/\bpercent of/, "*0.01*")
+    expr.gsub!(/\bpercent/, "*0.01")
+    expr.gsub!(/\% of\b/, "*0.01*")
+    expr.gsub!(/\%/, "*0.01")
+    expr.gsub!(/\bsquare root of (\d+)/, "\1 ** 0.5 ")
+    expr.gsub!(/\bcubed? root of (\d+)/, "\1 **(1.0/3.0) ")
+    expr.gsub!(/ of /, " * ")
+    expr.gsub!(/(bit(-| )?)?xor(\'?e?d( with))?/, "^")
+    expr.gsub!(/(bit(-| )?)?or(\'?e?d( with))?/, "|")
+    expr.gsub!(/bit(-| )?and(\'?e?d( with))?/, "& ")
+    expr.gsub!(/(plus|and)/, "+")
+
+    if (expr =~ /^\s*[-\d*+\s()\/^\.\|\&\*\!]+\s*$/ &&
+       expr !~ /^\s*\(?\d+\.?\d*\)?\s*$/ &&
+       expr !~ /^\s*$/ &&
+       expr !~ /^\s*[( )]+\s*$/)
+
+       begin
+         debug "evaluating expression \"#{expr}\""
+         answer = eval(expr)
+         if answer =~ /^[-+\de\.]+$/
+           answer = sprintf("%1.12f", answer)
+           answer.gsub!(/\.?0+$/, "")
+           answer.gsub!(/(\.\d+)000\d+/, '\1')
+           if (answer.length > 30)
+             answer = "a number with >30 digits..."
+           end
+         end
+         m.reply answer
+       rescue Exception => e
+         puts "couldn't evaluate expression \"#{m.params}\": #{e}"
+         m.reply "illegal expression \"#{m.params}\""
+         return
+       end
+    else
+      m.reply "illegal expression \"#{m.params}\""
+      return
+    end
+  end
+end
+plugin = MathPlugin.new
+plugin.register("math")