thehowl / cford32

Package cford32 implements a base32-like encoding/decoding package, with the encoding scheme specified by Douglas Crockford.

cford32

Package cford32 implements a base32-like encoding/decoding package, with the encoding scheme specified by Douglas Crockford.

From the website, the requirements of said encoding scheme are to:

• Be human readable and machine readable.
• Be compact. Humans have difficulty in manipulating long strings of arbitrary symbols.
• Be error resistant. Entering the symbols must not require keyboarding gymnastics.
• Be pronounceable. Humans should be able to accurately transmit the symbols to other humans using a telephone.

This is slightly different from a simple difference in encoding table from the Go's stdlib encoding/base32, as when decoding the characters i I l L are parsed as 1, and o O is parsed as 0.

This package additionally provides ways to encode uint64's efficiently, as well as efficient encoding to a lowercase variation of the encoding. The encodings never use paddings.

Why?

The main purpose I envision for this package is to create small, friendly, case-insensitive IDs. The encoding and decoding functions exist to match the API of similar packages like the standard library base32, and as such supporting adapting the code of this package for other use cases.

Examples

package main

import (
	"fmt"
	"math/rand"

	"github.com/thehowl/cford32"
)

func main() {
	gen := rand.New(rand.NewSource(12345))

	for i := 0; i < 6; i++ {
		// 1 << 35 allows us to show diverse set of compact/extended
		n := uint64(gen.Int63n(1 << 35))
		fmt.Printf("%11d: %s\n", n, string(cford32.PutCompact(n)))
	}

	// Output:
	// 14334683418: db6kt8t
	// 34093059390: g00000zr1nk9y
	//   417819965: 0ceev9x
	// 17538543416: g00000gap1vsr
	//  5407252823: 514r8aq
	// 16008560262: ex2yfm6
}