mapsorter

README

Mapsorter

Golang map sorter that frees you of writing boilerplate sorting code each time

When can it be useful? Imagine, you have a map with the data and want to get slice of its keys that:

• ordered of keys by string length, string value, datetime, int or float converted from strings or as native types;
• ordered of values by string length, string value, datetime, int or float converted from strings or as native types;
• in reverse order or only top N of the sorted results.

Not clear enough? See examples below.

Table of contents

• Mapsorter
  • Installation
  • Basic usage
    • The functional style
      • Using options
    • The struct style
      • Using options
  • Benchmarking

Installation

go get github.com/mehanizm/mapsorter

Basic usage

You can see working examples in cmd/main.go or in the tests.

The lib has two different api. Please, use whichever is more convenient for you.

The functional style

in := map[int]string{
	1: "a",
	2: "a",
	4: "c",
	3: "b",
}
sortedKeys, err := mapsorter.Sort(in, mapsorter.ByKeys, mapsorter.AsInt, true, 3)
if err != nil {
	panic(err)
}
for _, key := range sortedKeys {
	fmt.Println(key)
}
// >> 4
// >> 3
// >> 2

Using options

Sort function has four extending options.

SortBy

• ByKeys
• ByValues

SortAs

• AsString
• AsStringByLength
• AsInt
• AsFloat
• AsDatetime

These options are defined as enum package constants for easy using.

And two more:

reverse – bool flag to choose reverse sorting order if needed.

top – int count of top result to return.

The struct style

in := map[int]string{
	1: "a",
	2: "a",
	4: "c",
	3: "b",
}
sortedKeys, err := mapsorter.Map(in).ByValues().AsStringByLength().Reverse().Top(1).Sort()
if err != nil {
	panic(err)
}
for _, key := range sortedKeys {
	fmt.Println(key)
}
// >>  4

Or you can use MustSort() wrapper that panic if there is an internal error, be careful. But not so verbose.

for _, key := range mapsorter.Map(in).ByValues().AsStringByLength().Reverse().Top(1).MustSort() {
	fmt.Println(key)
}
// >>  4

Using options

All options can be changes with struct methods:

• ByKeys() – sort by keys,
• ByValues() – sort by values,
• AsString() – sort as strings,
• AsStringByLength() – sort as string lengths,
• AsInt() – sort as ints,
• AsFloat() – sort as floats,
• AsDatetime() – sort as datetime (with smart conversion),
• Forward() – forward order,
• Reverse() – reverse order,
• Top(top) – top N of sorted results,
• All() – all results.

Benchmarking

You can see some benchmark tests comparing mapsorter with straightforward boilerplate go code. Them shows approximately 5 times decreasing of all metrics. But save time, planet and keys on your keyboard! :)

With love ❤️

Documentation

Index

• func Map(mapToSort interface{}) *sorter
• func Sort(mapToSortInterface interface{}, sortBy By, sortAs As, reverse bool, top int) (res []interface{}, err error)
• type As
• type By

Functions

func Map

func Map(mapToSort interface{}) *sorter

func Sort

func Sort(mapToSortInterface interface{}, sortBy By,
	sortAs As, reverse bool, top int) (res []interface{}, err error)

Types

type As

type As uint8

const (
	AsString As = iota
	AsStringByLength
	AsInt
	AsFloat
	AsDatetime
)

type By

type By uint8

const (
	ByKeys By = iota
	ByValues
)