Mulset

Why?

• I've been frustrated with Python collections for a long time [1]_ [2]_
  • Too much cognitive overhead
  • Incomplete functionality
• Too many combinations of collection attributes to comprehend, code or maintain distinctly
  • unique
  • ordered
  • indexed
  • mutable
  • value restrictions (hashable -> fast contains check)
  • default values / generators / functions
  • multi-value mappings
• Consistent APIs
  • add or remove to all collections
• Inheriting from and extending list, dict, set ... is non-idiomatic

.. _[1]: https://mail.python.org/archives/list/python-ideas@python.org/thread/DOGT3OG57ZAQYJECUR27GUV5QM5HVWZL/ .. _[2]: https://github.com/mlenzen/collections-extended/blob/master/HISTORY.rst

How

• Collection functionality must be composed and the mechanics hidden behind the scenes ("collections for humans")

What's Different

• Mappings are simpler, they are Collections of tuples

• Mappings have keys and values that are MulSet views which can also be unique, ...

  • Specify values collection type?

• Consistency between collections

  • e.g. they all have .add
    • for lists this is append
    • for dicts this is adding a tuple

• Abstract store

  • shared core API could be more explicitly mutable under

• Need to abstract away the store so that Mapping views can easily do everything the MulSet proper can

• Everything is ordered?

  • Just by default?