config: replace the comma separator by new-line in ListAttribute

[Exirel]

Sopel 7.x task list:

• Use newlines in ListAttribute (see config: split ListAttribute values on newlines #1628)
• Update documentation to discourage usage of comma-separated values (see config: split ListAttribute values on newlines #1628 too)
• Fix core.channels (fixed by config: quote ListAttribute items when required #1690)
• Update site's tutorial, wiki, etc. to discourage usage of comma-separated values (pushed to WIP Sopel 7 site update at Sopel 7 notes sopel.chat#17)

Sopel 8.x and 9.x task list:

• Deprecation Warning for comma-separated values in Sopel 8.x (see config: deprecate using a comma instead of a newline in ListAttribute #2252)
• Remove management of comma-separated values in Sopel 9.x

TL;DR: in Sopel 7.x, I want to detect \n to switch to a new mode that doesn't require a delimiter with escape character.

Disclaimer: an escape mechanism was brought in for Sopel 7.x by #1460 to allow comma-separated values. I think it's a great achievement but, sadly, also something that I may want to remove entirely. I'm fully aware that this may mean having to throw off the hard work put in by @HumorBaby and I want to re-assert how much respect I've for his works, past and present.

Current state in Sopel 6.6.x

As of today's version of Sopel 6.6.x branch, this config file:

[spam]
eggs = one, two, three, four, and a half
bacons = grilled
    burn out
    greasy, fat, and tasty

will be read as this:

>>> config.spam.eggs
['one', ' two', ' three', ' four', ' and a half']
>>> config.spam.bacons
['grilled\nburn out\ngreasy', 'fat', 'and tasty']

Current state in Sopel master

In the master branch, since #1460, it is possible to escape the comma, so it would be like that:

[spam]
eggs = one, two, three, four, and a half
eggs_safe = one, four\, and a half
bacons = grilled
    burn out
    greasy, fat, and tasty

which result in eggs_safe to be properly handled, but leaving bacons still in a poor state:

>>> config.spam.eggs_safe
['one', 'four, and a half']
>>> config.spam.bacons
['grilled\nburn out\ngreasy', 'fat', 'and tasty']

And now, if we want to throw regex pattern (that need to be escaped too), what do we have?

[spam]
regex_pattern = ^Full stop\, Period\\.$, also:? this pattern$
regex_multilines =
    ^Full stop, Period\.$
    also:? this pattern$

Sure thing, regex patterns are not the easiest things to read, but I found that the multi-lines version far more readable.

What's next? What's my plan?

If we take back the example for Sopel 6.6.x:

[spam]
eggs = one, two, three, four, and a half
bacons = grilled
    burn out
    greasy, fat, and tasty

I want that output:

>>> config.spam.eggs
['one', 'two', 'three', 'four', 'and a half']
>>> config.spam.bacons
['grilled', 'burn out', 'greasy, fat, and tasty']

For Sopel 7.x I want to implement that so:

• no escape delimiter
• single-line expressions will be split by comma, as it is today
• multi-line expressions will be split by break-line, *without split by comma

Then in Sopel 8.x, I want to add a "deprecation warning" on single-line expressions.

Then in Sopel 9.x, I want to remove single-line expressions handling (ie. no more split by comma).

[dgw]

OK, tagged for 7 while you get the newline stuff done (and revert whatever escaping support you need to revert). This is kind of a tracking issue, and we'll punt it to the next milestone whenever each step is done.

[HumorBaby]

and I want to re-assert how much respect I've for his works, past and present

@Exirel you're too kind 😄 don't worry I'm not offended you want to scrap this feature so soon 😆 ya gotta do what ya gotta do... your proposed plan definitely seems like the way to go anyway 👍

[dgw]

@HumorBaby So I take it you'll be eagerly awaiting your chance to refactor #1528 on top of the newline list parsing when it's done? 😁 (Not that I know if any changes will be required, yet.)

[HumorBaby]

So I take it you'll be eagerly awaiting your chance to refactor #1528 on top of the newline list parsing when it's done? (Not that I know if any changes will be required, yet.)

I can barely contain myself!

[HumorBaby]

@dgw said:

So I take it you'll be eagerly awaiting your chance to refactor #1528 on top of the newline list parsing when it's done? grin (Not that I know if any changes will be required, yet.)

Only doc(+docstring) changes will be needed anywhere there is a reference to/use of comma delimiting in ListAttributes.

[dgw]

@Exirel After merging #1628, I have discovered that core.channels does NOT work with the new multi-line format. Channel names pretty much always start with #, which marks them as comments, so the config loads an empty option. :/

[Exirel]

@dgw issue with channel has been fixed and merged into master. All is left to do for Sopel 7 is the doc part.

[dgw]

Doc part is done, I think. Checked off.

[Exirel]

All is done for Sopel 8.