add OILS_COMP_UI

[melvinw]

This will be more user-friendly than the existing command-line arg, since people can set it in their init files.

[andychu]

OK I think this is a good change

We should document it in:

• doc/ref/toc-osh - maybe near OILS_VERSION, add an [Interactive] section that lists OILS_COMP_UI
• doc/ref/toc-ysh - ditto - applies to both OSH and YSH
• doc/ref/chap-special-var.md - there should be a ## Interactive, and then ### OILS_COMP_UI

and I would mention that it is only consulted at startup

(and then we can also document OILS_MAX_COMP_LINES in the same place)

---

It is possible to write a test for this? I guess it is hard to test because it changes the TAB behavior only ...

I suppose the only way we have of testing that is spec/stateful, which uses pexpect

I guess we are going to run into the same issue with OILS_MAX_COMP_LINES - it is hard to test

hmmmm

[melvinw]

Pushed some docs. Let me know if I should tweak the wording

[andychu]

Looks good!

[andychu]

I would say "GNU readline" because some people might not know what "readline" is

I think it will nicer to read with a bulleted list, like

• minimal - ...
• nice - ...

[melvinw]

👍 done

[andychu]

Great thanks!

I pushed a test/manual.sh for now ... I am wondering about this ENV.OILS_COMP_UI issue for YSH, which I started doing in November or so ...

( I am trying to untangle the confusion of global vars in shell ... which ones are from ENV and which ones aren't? There are a bunch of quirks around PWD, PS1, etc. )