The enum package provides a robust implementation of enumerations (enums) for R, enabling the creation of type-safe, validated sets of named constants. Enums help prevent errors by constraining variables to predefined values and offer better code readability and maintainability.

You can install the development version of enum from GitHub with:

# install.packages("pak")
pak::pak("milanmlft/enum")

library(enum)
# Create an enum for days of the week
Days <- Enum(
  MONDAY = 1,
  TUESDAY = 2,
  WEDNESDAY = 3,
  THURSDAY = 4,
  FRIDAY = 5,
  SATURDAY = 6,
  SUNDAY = 7
)
# Use the enum
today <- Days$MONDAY
today
#> [1] 1

• Validation: Values are automatically validated against defined constants
• Readability: Named constants make code more self-documenting
• Maintainability: Centralized definition of related constants

Enums support the following accessors:

• $: Access a single value by name
• [[: Access multiple values by name
• names: Get the names of the enum

Days[["MONDAY"]]
#> [1] 1
Days$TUESDAY
#> [1] 2
names(Days)
#> [1] "MONDAY"    "TUESDAY"   "WEDNESDAY" "THURSDAY"  "FRIDAY"    "SATURDAY"
#> [7] "SUNDAY"

All enum names must be unique and non-empty strings.

Days <- Enum(
  MONDAY = 1,
  MONDAY = 2
)
#> Error: Duplicate enum names

Days <- Enum(
  MONDAY = 1,
  2
)
#> Error: All enum values must be named

Enums are immutable, meaning that once created, their values cannot be changed.

Days$MONDAY <- 8
#> Error: Cannot modify enum

This package uses pre-commit hooks to ensure code quality. To set up the development environment:

# Install pre-commit
pip install pre-commit
# Install the hooks
pre-commit install
# Run hooks manually
pre-commit run --all-files

This project is licensed under the MIT License - see the LICENSE file for details.