https://github.com/glours/go2funk

Simple Golang API to use functional types in Golang, such as immutable List, Options, Try, Either...
https://github.com/glours/go2funk

functional functional-programming generics go golang program

Last synced: 19 days ago
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Simple Golang API to use functional types in Golang, such as immutable List, Options, Try, Either...

• Host: GitHub
• URL: https://github.com/glours/go2funk
• Owner: glours
• Created: 2020-09-16T22:59:39.000Z (about 4 years ago)
• Default Branch: main
• Last Pushed: 2023-07-22T20:06:49.000Z (over 1 year ago)
• Last Synced: 2024-10-17T19:46:18.056Z (29 days ago)
• Topics: functional, functional-programming, generics, go, golang, program
• Language: Go
• Homepage:
• Size: 58.6 KB
• Stars: 7
• Watchers: 5
• Forks: 0
• Open Issues: 8
• Metadata Files:
  • Readme: README.md

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README

        
# Go2Funk

Go2Funk is a pet project to test Go2 Generics and see how this new feature help us to implement some functional

structures easily.  

The idea is to keep this repo as much as possible dependency free.

## How to compile

Golang `1.18` has been release with type parameters.   

You can now, compile and test your code as usual (`go build`, `go test` ...)

You can also use Docker Dev Environments to develop this project:

* Open Docker Desktop

* Go to Dev Environments view

* Copy/Paste the git repo URL to start working!   

  

Check the configuration of the base image in the `.docker/config.json` config file

## Build

use `go build  ./...` or if you

use [Goland then configure external tools](https://www.jetbrains.com/help/go/how-to-use-type-parameters-for-generic-programming.html)

## Run tests

use `go test -v ./...` or if you

use [Goland then configure external tools](https://www.jetbrains.com/help/go/how-to-use-type-parameters-for-generic-programming.html)

## Usage

### Collection types

#### List

```go

myIntArray := []int{1, 2, 3, 4, 5}

myList := OfSlice[int](myIntArray)

myList = myList.Append(6)

fmt.Println(myList.Length())

var mapper = func (value int) string { return strconv.Itoa(value) }

var evenPredicate = func (value int) bool { return value % 2 == 0 }

myList = MapList[int, string](myList.Filter(evenPredicate), mapper); 

```

For more usage details check [tests](./api/collection/list_test.go).

### Control types

#### Option

```go

empytOption := Empty[int]()

someOption := Of[int](10)

fmt.Println(emptyOption.GetOrElse(5)) // Print 5

fmt.Println(someOption.GetOrElse(5)) // Print 10

var evenPredicate = func (value int) bool { return value % 2 == 0 }

fmt.Println(some.Filter(eventPredicate).IsEmpty()) #Print false

var mapper = func (value int) string { return strconv.Itoa(value) }

fmt.Println(MapOption(someOption, mapper)) // Print "10"

```

For more usage details check [tests](./api/control/option_test.go).

#### Try

```go

defaultTryError := errors.New("default Try error")

failure := FailureOf[int](defaultTryError)

success := SuccessOf[int](10)

fmt.Println(failure.GetOrElse(5)) // Print 5

fmt.Println(someOption.GetOrElse(5)) // Print 10

fmt.Println(failure.GetOrElseCause()) // Print "default Try error"

fmt.Println(someOption.GetOrElseCause()) // Print 10

successLambda := func ()(int, error) { return 10, nil})

failureLambda := func ()(int, error) {return 0, defaultTryError }

fmt.Println(TryOf(failureLambda).IsFailure()) // Print true

fmt.Println(TryOf(successLambda).IsFailure()) // Print false

```

For more usage details check [tests](./api/control/try_test.go).

#### Either

```go

defaultEitherError = errors.New("default Either error")

right = RightOf[error, int](10)

left = LeftOf[error, int](defaultEitherError)

fmt.Println(right.GetOrElse(20)) // Print 10

fmt.Println(left.GetOrElse(20)) // Print 20

fmt.Println(right.GetLeftOrElse(error.New("new error"))) // Print "new error"

fmt.Println(left.GetOrElse(error.New("new error"))) // Print "default Either error"

var mapper = func (value int) string { return strconv.Itoa(value) }

var mapRight Either[error, string] = MapEither(right, mapper)

fmt.Println(mapRight.GetOrElse("good")) // Print "10"

```

For more usage details check [tests](./api/control/either_test.go).