Repository navigation
Document side effects of := on keys #7409
Description
The use of copy() here is subtle, it might be good to describe how to approach side effects a bit better in the documentation.
Originally posted by @MichaelChirico in #7401 (comment)
This should be added to our reference semantics vignette and probably to help(':=') if its not already there.
Activity
MichaelChirico commentedon Nov 4, 2025
Oh, in the PR, what I meant is that it looks like
Will run
copy()for each level ofoptimization, so there's a lazy evaluation aspect toxwhenoptimization=is provided that impacts how to read and write tests using the new argument. Does that make sense?ben-schwen commentedon Nov 4, 2025
I see. In principle it is that seem as for other tests. If multiple execution of a single test works, then the execution of different optimization levels will also work. If a tests already has side effects such that running it twice will error, then ofc running it with different optimization levels will also error.
Hence, one could say that
is short for
Clarify when := drops keys and when to use copy()