Changes in version 0.3.0 (2021-02-05)                  

  - Changed the Iterator to use an environment as a backend instead of a
    list, and added clone()

  - Added a well-defined search path for Iterators

  - Made error messages more clear for Iterator

  - Added move_while()

  - Added access to the current iteration number with .iter

  - Completely changed the move_*() backend to use yield_*()

  - Changed the we_have() backend to be fully lazy

  - Removed dependency on {purrr}

  - Added new features to set comprehension with Iterators

                 Changes in version 0.2.0 (2021-01-06)                  

  - Removed as_Iterator()

  - Changed is_Iterator() to use inherits() instead of class() ==

  - Fixed bug in we_have() that wrote over an old set-created Iterator
    when a new one was made, even with a different name

  - Removed hash_df data structure

  - Removed dependency on {R6}

  - Added yield_more()

  - Added move_next() and move_more()

  - Added current()

  - Added yield_while()

                 Changes in version 0.1.0 (2020-12-21)                  

  - Initial Release

  - Added a NEWS.md file to track changes to the package.