hlist_class: Create a subclass of 'HList'
In jrnold/r-checker: Data frames with column and table constraints

Description Usage Arguments Value See Also Examples

Create a subclass of HList, which restricts elements of the list to be a specified class.

1 2	hlist_class(Class, classtype = "ANY", empty_names = TRUE, unique_names = FALSE, where = topenv(parent.frame()))

`Class`	`character` string name of the new class that will extend `HList`.
`classtype`	`character` The name of the class which all elements must inherit from.
`empty_names`	`logical` If `FALSE`, then no names can have values `""` or `NA`.
`unique_names`	`logical` If `TRUE`, then names must be unique.
`where`	Passed to `setClass`. The environment in which to store the definition.

function with usage function(...), which will create objects of the newly defined class.

"FunctionList" for a subclass created with this function used in this section. HList.

NumericList <-
  hlist_class("NumericList", "numeric")
# creates a new class "NumericList"
showClass("NumericList")
# Create a new object of class NumericList
foo <- NumericList(a=1, b=2)
print(foo)
foo[["c"]] <- 3
print(foo)
# error
try(foo[["c"]] <- 3)