https://go2goplay.golang.org/p/o7JoBzJw3Hv

curry.go2

package main

import (
	"fmt"
	"strings"
)

type Tuple(type A, B) interface {
	Head() A
	Tail() B
	Unwrap() (A, B)
}

type tuple(type A, B) struct {
	A A
	B B
}

func (u tuple(A, B)) Head() A {
	return u.A
}

func (u tuple(A, B)) Tail() B {
	return u.B
}

func (u tuple(A, B)) Unwrap() (A, B) {
	return u.A, u.B
}

func New(type A, B)(a A, b B) Tuple(A, B) {
	return tuple(A, B){a, b}
}

func NewNothing(type A)(a A) Tuple(A, Nothing) {
	return tuple(A, Nothing){a, Nothing{}}
}

type Nothing struct{}

func curry(type
	IA, IB, RA, RB interface{},
	R Tuple(RA, RB),
)(a IA, fn func(t Tuple(IA, IB)) R) func(IB) R {
	return func(b IB) R {
		return fn(New(a, b))
	}
}

func Curried(type A, B, R)(f func(A, B) R) func(t Tuple(A, B)) Tuple(R, Nothing) {
	return func(t Tuple(A, B)) Tuple(R, Nothing) {
		return NewNothing(f(t.Head(), t.Tail()))
	}
}

func Curried2(type A, B, RA, RB)(f func(A, B) (RA, RB)) func(t Tuple(A, B)) Tuple(RA, RB) {
	return func(t Tuple(A, B)) Tuple(RA, RB) {
		return New(f(t.Head(), t.Tail()))
	}
}

func Join(t Tuple(string, []string)) Tuple(string, Nothing) {
	return NewNothing(strings.Join(t.Tail(), t.Head()))
}

func main() {
	cur := curry(string, []string, string, Nothing, Tuple(string, Nothing))(", ", Join)
	fmt.Println(cur([]string{"Hello", "playground"}).Unwrap())
}