Over 22 fields in play-json case class. How to deal.

how-to-do-without-tuple-horror.scala

import play.api.libs.json._
import play.api.libs.functional.syntax._

case class AToM(
	a: Int,
	b: Int,
	c: Int,
	d: Int,
	e: Int,
	f: Int,
	g: Int,
	h: Int,
	i: Int,
	j: Int,
	k: Int,
	l: Int,
	m: Int
)

case class NToZ(
	n: Int,
	o: Int,
	p: Int,
	q: Int,
	r: Int,
	s: Int,
	t: Int,
	u: Int,
	v: Int,
	w: Int,
	x: Int,
	y: Int,
	z: Int
)

case class Large(
	a: Int,
	b: Int,
	c: Int,
	d: Int,
	e: Int,
	f: Int,
	g: Int,
	h: Int,
	i: Int,
	j: Int,
	k: Int,
	l: Int,
	m: Int,
	n: Int,
	o: Int,
	p: Int,
	q: Int,
	r: Int,
	s: Int,
	t: Int,
	u: Int,
	v: Int,
	w: Int,
	x: Int,
	y: Int,
	z: Int
)

implicit AToMFormat = Json.format[AToM]
implicit NToZFormat = Json.format[NToZ]

implicit val largeReader: Reads[Large] = {
	(AToMFormat.reads and NToZReads.reads)( (aToM, nToZ) =>
		Large(
			aToM.a,
			aToM.b,
			aToM.c,
			aToM.d,
			aToM.e,
			aToM.f,
			aToM.g,
			aToM.h,
			aToM.i,
			aToM.j,
			aToM.k,
			aToM.l,
			aToM.m,
			nToZ.n,
			nToZ.o,
			nToZ.p,
			nToZ.q,
			nToZ.r,
			nToZ.s,
			nToZ.t,
			nToZ.u,
			nToZ.v,
			nToZ.w,
			nToZ.x,
			nToZ.y,
			nToZ.z
		)
	)
}


val s = """{"a": 0,"b": 1,"c": 2,"d": 3,"e": 4,"f": 5,"g": 6,"h": 7,"i": 8,"j": 9,"k": 10,"l": 11,"m": 12,"n": 13,"o": 14,"p": 15,"q": 16,"r": 17,"s": 18,"t": 19,"u": 20,"v": 21,"w": 22,"x": 23,"y": 24,"z": 25}"""

scala> Json.parse(s).as[Large]
//Large(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25)

over-22-fields-json-play.scala

import play.api.libs.json._
import play.api.libs.functional.syntax._

case class Large(
    a: Int,
    b: Int,
    c: Int,
    d: Int,
    e: Int,
    f: Int,
    g: Int,
    h: Int,
    i: Int,
    j: Int,
    k: Int,
    l: Int,
    m: Int,
    n: Int,
    o: Int,
    p: Int,
    q: Int,
    r: Int,
    s: Int,
    t: Int,
    u: Int,
    v: Int,
    w: Int,
    x: Int,
    y: Int,
    z: Int
)

implicit val largeReader: Reads[Large] = {
    val aToMReads: Reads[Tuple13[Int, Int, Int,Int,Int,Int,Int,Int,Int,Int,Int,Int,Int]] = {
        (JsPath \ "a").read[Int] and
        (JsPath \ "b").read[Int] and
        (JsPath \ "c").read[Int] and
        (JsPath \ "d").read[Int] and
        (JsPath \ "e").read[Int] and
        (JsPath \ "f").read[Int] and
        (JsPath \ "g").read[Int] and
        (JsPath \ "h").read[Int] and
        (JsPath \ "i").read[Int] and
        (JsPath \ "j").read[Int] and
        (JsPath \ "k").read[Int] and
        (JsPath \ "l").read[Int] and
        (JsPath \ "m").read[Int]
    }.apply(Tuple13.apply[Int, Int, Int,Int,Int,Int,Int,Int,Int,Int,Int,Int,Int] _)

    val nToZReads: Reads[Tuple13[Int, Int, Int,Int,Int,Int,Int,Int,Int,Int,Int,Int,Int]] = {
        (JsPath \ "n").read[Int] and
        (JsPath \ "o").read[Int] and
        (JsPath \ "p").read[Int] and
        (JsPath \ "q").read[Int] and
        (JsPath \ "r").read[Int] and
        (JsPath \ "s").read[Int] and
        (JsPath \ "t").read[Int] and
        (JsPath \ "u").read[Int] and
        (JsPath \ "v").read[Int] and
        (JsPath \ "w").read[Int] and
        (JsPath \ "x").read[Int] and
        (JsPath \ "y").read[Int] and
        (JsPath \ "z").read[Int]
    }.apply(Tuple13.apply[Int, Int, Int,Int,Int,Int,Int,Int,Int,Int,Int,Int,Int] _)

    (aToMReads and nToZReads)( (aToM, nToZ) =>
        Large(
            aToM._1,
            aToM._2,
            aToM._3,
            aToM._4,
            aToM._5,
            aToM._6,
            aToM._7,
            aToM._8,
            aToM._9,
            aToM._10,
            aToM._11,
            aToM._12,
            aToM._13,
            nToZ._1,
            nToZ._2,
            nToZ._3,
            nToZ._4,
            nToZ._5,
            nToZ._6,
            nToZ._7,
            nToZ._8,
            nToZ._9,
            nToZ._10,
            nToZ._11,
            nToZ._12,
            nToZ._13
        )
    )
}


val s = """{"a": 0,"b": 1,"c": 2,"d": 3,"e": 4,"f": 5,"g": 6,"h": 7,"i": 8,"j": 9,"k": 10,"l": 11,"m": 12,"n": 13,"o": 14,"p": 15,"q": 16,"r": 17,"s": 18,"t": 19,"u": 20,"v": 21,"w": 22,"x": 23,"y": 24,"z": 25}"""

scala> Json.parse(s).as[Large]
//Large(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25)