Use an environment as the base type of an S7 class

class_environment is the base wrapper for environments. Unlike all other R objects, environments have reference semantics, i.e., they are modified in place. It's not clear what all the implications of this are for S7, so we are marking the use of class_environment as experimental.

Its use is subject to the following caveats:

• S7_data() and S7_data<-() error, because swapping the underlying data would destroy the existing attributes.

• The default convert() method errors when upcasting to an environment because stripping the subclass's properties would mutate from in place.

Usage

class_environment

Examples

Counter := new_class(class_environment)
counter <- Counter()
counter$n <- 0L

# Reference semantics: `copy` and `counter` are the same object, so
# mutating one is visible through the other.
copy <- counter
copy$n <- 10L
counter$n
#> [1] 10