From: "Iñaki Baz Castillo" <ibc@...>
Date: 2008-05-03T07:00:33+09:00
Subject: How to access to an Array element without doing "find" each time

Hi, I've an Array containing complex objects of Header class:

-------------------------------------
class Header
	#attributes:
	# - @name
	# - @original_value
	# - @parsed_value
	# ...
end

class Message
	#attributes:
	# - @first_line
	# - @headers =
	#      [header_1, header_2, header_3...]
	# - @body
end
-------------------------------------

Just some headers are parsed, and for a header "From", @name attribute can be:
  "From", "from", "FROM", "F", "f" ... =>   /^(from|f)$/i


Now I need to access a specifi header ("From" for example) several times and I 
want to avoid doing a "Header.find { |h| h.name =~  /^(from|f)$/i }" for each 
access,so:

class Message
	def header(name)
		Header.find { |h| h.name =~  /^(from|f)$/i }
	end
end


But doing message.header("From") for each access will be not very efficient 
and I try to avoid it. Is there any other way?

I could doing an assigment just the first time:

  message.hdr_from = message.header("From")
  ...do_somethig_with_hdr_from... :
  message.hdr_from.parsed_value.uri
  message.hdr_from.parsed_value.uri.name
  message.hdr_from.parsed_value.display_name
  ...

So "hdr_from" is like a pointer to header("From"), but it's not valid for me 
since I need the possibility of doing a re-assignement:

  header("From") = header("To")

So if after doing that I use "message.hdr_from" I will access to the previous 
value of "From" header instead of the new one.


In fact, what I'm looking for is a persister pointer, concept that I already 
know doesn't exist in Ruby :(

Thanks for any suggestion.



-- 
Iñaki Baz Castillo