Configuration File Support

[BebeSparkelSparkel]

It seems natural to allow intermixing of command line parameters and configuration file parameters.

I have not figured out a good way of implementing this yet but I have written a crude start. BebeSparkelSparkel@58ccaa7?diff=unified#diff-0fdf6337b7344d0659520693ed886d16bcaa1726b984e9a032da849ed05c61e7

One of the problems is that the structure and parsing work already completed to create conf is lost in the merge back to State. One poor solution I have thought of is changing State to something like

type State = [Item]
data Item
  = ItemUnparsed String
  | ItemParsed Dynamic

which allows preparsed data to be passed through.

Do you have any thoughts on how to accomplish this?

[SamuelSchlesinger]

Not sure I agree config files belong in the backtracking way parsing works with commander-cli

[BebeSparkelSparkel]

Something that I have found to be very useful is being able to have cli arguments overpower with config file settings.
I do appreciate your non intermixing of config opinion because there is not a good way merging differing structures well.

[SamuelSchlesinger]

I guess the way I'd include a config is by a path parameter or an environment variable, but maybe I'm missing something useful. Is there a good example where this was quite helpful?

[BebeSparkelSparkel]

This isn't a great example but bitcoind allows for this behavior
https://manpages.debian.org/testing/bitcoind/bitcoind.1.en.html

The conf file field can be superseded by the cli parameter

[SamuelSchlesinger]

Interesting, yeah I mean if there's a widely used tool that has that behavior I'm open to a patch to support it.

[BebeSparkelSparkel]

I currently do not have a good design for this. Do you have any thoughts on the limited expressiveness of the state? The Parameter Sections #48 could be a solution for nested structures.

[SamuelSchlesinger]

I feel like there's a world where state is modular, I'd have to take a hack at it though.

[SamuelSchlesinger]

Thinking at this again, I feel like configuration files being part of backtracking might be likely to create confusion among newer users.