How to Choose Between Maps, Structs, and Keyword Lists

Ask yourself these questions (in this order):

• Do I want to pattern-match against the contents (for example, matching a dictionary that has a key of :name somewhere in it)?

  If so, use a map.

• Will I want more than one entry with the same key?

  If so, you’ll have to use the Keyword module.

• Do I need to guarantee the elements are ordered?

  If so, again, use the Keyword module.

• Do I have a fixed set of fields (that is, is the structure of the data always the same)?

  If so, use a struct.

• Otherwise, if you’ve reached this point,

  Use a map.