imulab / go-enum

Object as the next best thing before Go supports a more useable enum.

go-enum

Object as the next best thing before Go supports a more useable enum.

Motivation

Go does not have an explicit enum keyword to associate string based values with integer based indexes. String values are necessary for human consumption while integer based indexes are necessary to save storage spaces. The lack of a automatic conversion mechanism makes writing persistence layer quite painful. This small library is to cover the simple use case of converting between string values and integer indexes.

Install

go get -u github.com/imulab/go-enum

Usage

The simple use case is to create an enum for single value purposes:

options := enum.New("red", "green", "blue")

// Get indexes (which could be saved to database)
options.Index("red")   // 1
options.Index("green") // 2
options.Index("blue")  // 3

// Restore values from indexes
options.Value(1) // red
options.Value(2) // green
options.Value(3) // blue

The second use case is to create an enum for multiple value purposes:

multiSelect := enum.NewComposite("one", "two", "three")

// Get indexes, same as before, but in the order of 2
options.Index("one")   // 1
options.Index("two")   // 2
options.Index("three") // 4

// Compute a bitmap to represent multiple values together
multiSelect.BitMap("one", "three") // 5

// Hydrate/Restore values from bitmap
multiSelect.Hydrate(5) // ["one", "three"]

For details, please consult Go Doc.