Callback should be the last argument

[diversario]

Having something other than a callback as the last function argument goes against node conventions and it's inconsistent with other methods in the module that have callback as the last argument.

[alevy]

I agree, but for now, it's done for backwards compatability, since some parameters were added after the fact. See #50 for a short discussion on the matter. I plan on making this change eventually, and am more than happy to merge pull requests so long as they either maintain backwards compatability or have a reasonable upgrade path (even if either is hacky for now).

[rdegges]

I think the long-term solution to this is to release a major release (1.0.0 type stuff), which breaks backwards compatibility. Semantic Versioning typically works this way: major releases which increase the first number are expected to introduce backwards-compatibility breaking behaviors.

[dterei]

Amit, I think there are four options here:

1. Add variants of functions, basic:

   var set = function(key, value, callback)
   var set_ = function(key, value, flags, expires, version)
   

2. Use a dictionary for all arguments:

   var set = function(args, callback)
   set({key: 'hello', value: 'world'}, function(...
   

3. Use a dictionary for extended arguments:

   var set = function(key, value, options, callback)
   set('hello', 'world', {}, function(...
   

4. Similar to (1), but have the advance variant take a dictionary to make the code easier to read:

   var set = function(key, value, callback)
   var set_ = function(key, value, args, callback)
   set_('hello', 'world', {expires: 100, flags: 1337, version: 37}, function(...
   

In terms of what the ideal function interfaces should look like (ignoring backwards compatibility for now).

Once we choose a style, I think we just make a break changing with a version between or two with deprecations for migration time.