as_enum: Coerce lists, environments, and factors to enumerations

In ElianHugh/enumr: Static Enumerations

Description

as_enum() turns an existing object into an enumeration. Coercion can be used when you want to create an enum, but don't know what the exact values each member will contain at runtime. This is comparable to the as.list method.

As an S3 generic, as_enum() holds methods for:

• list: wrapper function that passes the list to new_generic_enum()

• data.frame: coerces a data.frame to a list ( dropping row names in the process), and supplies the list of objects to new_generic_enum()

• environment: coerces an environment to a list, and supplies the list of objects to new_generic_enum()

• factor: constructs a list of name/value pairs from a factor, supplies the list to new_numeric_enum().

• Default: attempt to coerce to a list, then to an enum

Usage

as_enum(x, ...)

## S3 method for class 'list'
as_enum(x, ...)

## S3 method for class 'environment'
as_enum(x, ..., .all_names = FALSE, .sorted = TRUE)

## S3 method for class 'factor'
as_enum(x, ..., .sorted = TRUE)

## S3 method for class 'data.frame'
as_enum(x, ..., use_cols = FALSE, use_rows = FALSE)

## S3 method for class ''NULL''
as_enum(x, ...)

## Default S3 method:
as_enum(x, ...)

Arguments

x	the object to coerce to enum
...	parameters to pass to further methods
.all_names	whether to include variables with a dot .
.sorted	whether the object elements should be sorted
use_cols	cols of the data frame are used for name/value pairs instead of the data frame's observations
use_rows	rows of the data frame are used for name/value pairs instead of the data frame's observations

Value

An enumeration (enum), a list of unique name/value pairs

See Also

enum() create an enum from supplied arguments. new_generic_enum() and new_numeric_enum() create enums from a list of arguments.

Examples

as_enum(list(x = 5, y = "str"))

as_enum(rlang::env(a = 1, b = "str"))

as_enum(factor(c("January", "February", "December"), levels = month.name))

as_enum(mtcars)

as_enum(mtcars, use_cols = TRUE)

as_enum(mtcars, use_rows = TRUE)

ElianHugh/enumr documentation built on Dec. 17, 2021, 6:25 p.m.