Parse/dump float values as per de facto spec

Reference discussion here: http://librelist.com/browser//mongrel2/2011/5/14/proposal-for-tnetstrings-floats/#3eacab75c5ca691348735f8a9894c60e

And also https://github.com/asinger/tnetstringsj as well as items like the Mongrel2 adapters.

lib/tnetstring.rb

@@ -22,6 +22,8 @@ def self.parse(tnetstring)
     value = case payload_type
     when '#'
       payload.to_i
+    when '^'
+      payload.to_f
     when ','
       payload
     when ']'
@@ -145,6 +147,9 @@ def self.dump(obj)
     if obj.kind_of?(Integer)
       int_str = obj.to_s
       "#{int_str.length}:#{int_str}#"
+    elsif obj.kind_of?(Float)
+      float_str = obj.to_s
+      "#{float_str.length}:#{float_str}^"
     elsif obj.kind_of?(String) || obj.kind_of?(Symbol)
       "#{obj.length}:#{obj},"
     elsif obj.is_a?(TrueClass)

spec/tnetstring_spec.rb

@@ -2,8 +2,28 @@
 
 describe TNetstring do
   context "parsing" do
-    it "parses an integer" do
-      TNetstring.parse('5:12345#')[0].should == 12345
+    context "integers" do
+      it "parses a positive integer" do
+        TNetstring.parse('5:12345#')[0].should == 12345
+      end
+
+      it "parses a negative integer" do
+        TNetstring.parse('6:-12345#')[0].should == -12345
+      end
+    end
+
+    context "floats" do
+      it "parses a positve float" do
+        TNetstring.parse('3:3.5^')[0].should == 3.5
+      end
+
+      it "parses a negative float" do
+        TNetstring.parse('5:-3.14^')[0].should == -3.14
+      end
+
+      it "parses a float with leading zeros" do
+        TNetstring.parse('7:-000.14^')[0].should == -0.14
+      end
     end
 
     it "parses an empty string" do
@@ -78,8 +98,28 @@
   end
 
   context "dumping" do
-    it "dumps an integer" do
-      TNetstring.dump(42).should == "2:42#"
+    context "integers" do
+      it "dumps a positive integer" do
+        TNetstring.dump(42).should == "2:42#"
+      end
+
+      it "dumps a negative integer" do
+        TNetstring.dump(-42).should == "3:-42#"
+      end
+    end
+
+    context "floats" do
+      it "dumps a positive float" do
+        TNetstring.dump(12.3).should == "4:12.3^"
+      end
+
+      it "dumps a negative float" do
+        TNetstring.dump(-2.3).should == "4:-2.3^"
+      end
+
+      it "dumps a float with integral value" do
+        TNetstring.dump(-42.0).should == "5:-42.0^"
+      end
     end
 
     it "dumps a string" do