GistWriter-spec.swift

import Foundation

public typealias GistID = Int
public typealias Result = Int
public typealias ConfigDict = [String:String]


public class GistWriter { // when you create the instance it will be invalid

	private var activeGist: GistID?

	public func configure(configuration:ConfigDict) {
		//setup and whatnot
	}

	//return nil if the activeGist was not set beforehand
	public func updateGist(text:String) -> NSURL? {
		//createGist and setActiveGist if new

		return NSURL(string:"") //return url
	}

	public func reset() {} //start a new gist on next update

	private func createGist() -> GistID {
		return 1 //arbitrary id
	}

	//whatever support functions you need
	private func setActiveGist(id: GistID) {
		activeGist = id
	}
}

usage, so far:
instantiate the GistWriterThing
call updateGist(text) on the instance
call it several times will update the same gist
until you call reset
call updateGist(text) will create a new gist
call it several times will update the same gist
until you call reset
ad infinitum