Deconstructor

zio.blocks.schema.binding.Deconstructor

abstract class Deconstructor[-A]

A Deconstructor writes the fields of a value of type A into Registers: it is the deconstruction half of a Binding.Record. To encode a record, a codec calls deconstruct and then reads each field from the registers, at the positions that Reflect.Record#registers gives. Writing the fields into registers, instead of into a tuple or an array of boxed values, keeps primitive fields unboxed.

deconstruct writes at positions counted from its offset argument, with the same layout that the record's Constructor reads:

import zio.blocks.schema.binding._
import zio.blocks.schema.binding.RegisterOffset.RegisterOffset

case class Book(title: String, year: Int)

val bookDeconstructor: Deconstructor[Book] = new Deconstructor[Book] {
 def usedRegisters: RegisterOffset = RegisterOffset(objects = 1, ints = 1)

 def deconstruct(out: Registers, offset: RegisterOffset, in: Book): Unit = {
   out.setObject(offset, in.title)
   out.setInt(offset + RegisterOffset(objects = 1), in.year)
 }
}

val registers = Registers(bookDeconstructor.usedRegisters)
bookDeconstructor.deconstruct(registers, RegisterOffset.Zero, Book("Zionomicon", 2021))
val title = registers.getObject(RegisterOffset.Zero)     // "Zionomicon"
val year  = registers.getInt(RegisterOffset(objects = 1)) // 2021

Type parameters

A: the type of the values it takes apart

Attributes

See also: Register System
Source: Deconstructor.scala
Graph
Supertypes: class Object

trait Matchable

class Any
Known subtypes: class ConstantDeconstructor[A]
Self type: Deconstructor[A]

Members list

Value members

Abstract methods

Writes the fields of in into out, at positions counted from offset.

Attributes

Source: Deconstructor.scala

The registers that deconstruct writes, counted from its offset: the number of object slots and the number of bytes. Callers size their Registers with it.

Attributes

Source: Deconstructor.scala

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