Caching candidates in Helm functions

[Tianxiang Xiong]

When a Helm source's `:candidates` value is a function, e.g. here, is that function invoked to collect candidates every time the pattern is changed? Or only once from the time a Helm command using that source is invoked to when it's exited?

I'd like to make sure we're not doing unnecessary work in some performance-sensitive commands.

[Tianxiang Xiong]

Ah, I think it's the introduction of `:volatile t` that's causing recalculation every time the pattern changes. Does that seem correct?

[Thierry Volpiatto]

Tianxiang Xiong <tianxia...@gmail.com> writes:

> Ah, I think it's the introduction of `:volatile t` that's causing
> recalculation every time the pattern changes. Does that seem correct?

Yes, the definition of volatile is in `helm-source` documentation,
perhaps I can rewrite it if it is not clear? Let me know.
See also the definition of `helm-get-cached-candidates` to see exactly
what volatile does.

Note that volatile have no effect on async sources and is used
internally for in-buffer sources so you don't have to use it there.
IOW use it only on sync sources.

--
Thierry