TODO

TODO List

- Todo items begin with a dash
  * Starred items are done.

-* A starred Todo item is completely done.


- optimization -- rewrite redoTarget with sets:

  old = existing prerequisite keys
  new = new prerequisites keys
  
  deletes = old - new
  writes = new - old
  # updates
  for each file in old && new
      if !file.IsCurrent() {
          add file to deletes 
          add file to writes

  delete(deletes)
  put(writes)
  
  In most cases, this will eliminate a number of redundant operations.


- Increased verbosity should
  *  Show do file selected
     Show file stats for generated output

-  Add mechanism to run jobs in parallel
   
    Useful for 'redo' or 'ifchange' with multiple targets.

-   Add command to list database entries. Either for a single file or all files.
  
- Tests

    check arguments
    writing to stdout vs file
    cross project dependencies

- Use different database?

  Doubtlessly, an embedded SQL or key value database would be faster.
  Need to ensure serializable access.

-*  Add debug flag

-* Change verbosity > 2 behaviour to use debug

-  * Combine into single executable with commands.

    redux init
    redux ifchange
    redux ifcreate
    redux redo
    
    With links to redux for each command.

-* Rebuild binary for tests

-* Add support for multiple levels of extensions.
    See https://github.com/gyepisam/redux/issues/1