Logical flags should default to FALSE

[hadley]

So that you override them with something = TRUE

i.e. lazy_dt(dt, immutable = FALSE) would be better as lazy_dt(dt, mutable = FALSE)

From @lionel: This would mean that some functions would have a quiet parameter (verbose by default), and others would have a verbose parameter (quiet by default).

Maybe the general principle is that the name should be guided by the non-default usage so that when reading code you don't get double-negatives?

[jimhester]

This seems too arbitrary to be a general rule, sure it works in that particular example, but in many others I don't think it makes sense. e.g.

devtools::install() has a build argument or devools::check() both have cran arguments that default to TRUE. Trying to contort their names to default to FALSE doesn't seem worthwhile.

Also in regards to verbose vs quiet, I think having argument name consistency, e.g. all tidyverse functions consistently using either verbose or quiet would far outweigh the benefit proposed here.

This I think might be a good thing idea though

name should be guided by the non-default usage so that when reading code you avoid double-negatives

[hadley]

Yeah, I think the actual principle might just be: avoid creating logical arguments where the primary use is a double-negative: immutable = FALSE, drop = FALSE, etc