Add Cookie.cookie_value and Cookie.cookie_value_to_hash.

lib/http/cookie.rb

@@ -313,9 +313,7 @@ class HTTP::Cookie
       origin = URI(origin)
 
       [].tap { |cookies|
-        s = Scanner.new(set_cookie, logger)
-        until s.eos?
-          name, value, attrs = s.scan_cookie
+        Scanner.new(set_cookie, logger).scan_set_cookie { |name, value, attrs|
           break if name.nil? || name.empty?
 
           cookie = new(name, value)
@@ -352,7 +350,24 @@ class HTTP::Cookie
           yield cookie if block_given?
 
           cookies << cookie
-        end
+        }
+      }
+    end
+
+    # Takes an array of cookies and returns a string for use in the
+    # Cookie header, like "name1=value2; name2=value2".
+    def cookie_value(cookies)
+      cookies.join('; ')
+    end
+
+    # Parses a Cookie header value into a hash of name-value string
+    # pairs.  The first appearance takes precedence if multiple pairs
+    # with the same name occur.
+    def cookie_value_to_hash(cookie_value)
+      {}.tap { |hash|
+        Scanner.new(cookie_value).scan_cookie { |name, value|
+          hash[name] ||= value
+        }
       }
     end
   end

lib/http/cookie/scanner.rb

@@ -150,7 +150,14 @@ class HTTP::Cookie::Scanner < StringScanner
     tuple_to_time(day_of_month, month, year, time)
   end
 
-  def scan_cookie
+  def scan_set_cookie
+    unless block_given?
+      scan_set_cookie { |*values|
+        return values
+      }
+      return
+    end
+
     # RFC 6265 4.1.1 & 5.2
     until eos?
       start = pos
@@ -211,7 +218,29 @@ class HTTP::Cookie::Scanner < StringScanner
         next
       end
 
-      return [name, value, attrs] if value
+      yield name, value, attrs if value
+    end
+  end
+
+  def scan_cookie
+    unless block_given?
+      scan_cookie { |*values|
+        return values
+      }
+      return
+    end
+
+    # RFC 6265 4.1.1 & 5.4
+    until eos?
+      skip_wsp
+
+      name, value = scan_name_value
+
+      yield name, value if name && value
+
+      # The comma is used as separator for concatenating multiple
+      # values of a header.
+      skip(/[;,]/)
     end
   end
 end

test/test_http_cookie.rb

@@ -400,6 +400,28 @@ class TestHTTPCookie < Test::Unit::TestCase
       cookie = HTTP::Cookie.new('foo', value)
       assert_equal(cookie_value, cookie.cookie_value)
     }
+
+    pairs = [
+      ['Foo', 'value1'],
+      ['Bar', 'value 2'],
+      ['Baz', 'value3'],
+      ['Bar', 'value"4'],
+    ]
+
+    cookie_value = HTTP::Cookie.cookie_value(pairs.map { |name, value|
+        HTTP::Cookie.new(:name => name, :value => value)
+      })
+
+    assert_equal 'Foo=value1; Bar="value 2"; Baz=value3; Bar="value\\"4"', cookie_value
+
+    hash = HTTP::Cookie.cookie_value_to_hash(cookie_value)
+
+    assert_equal 3, hash.size
+
+    hash.each_pair { |name, value|
+      _, pvalue = pairs.assoc(name)
+      assert_equal pvalue, value
+    }
   end
 
   def test_set_cookie_value