#deep-copy code explainers

python

from copy import deepcopy
from typing import Any, Mapping

How a recursive deep merge works in Python

recursion immutability dictionaries

Intermediate 6 steps

java

public final class DeepCopier {
 
    private static final ObjectMapper MAPPER = new ObjectMapper()
            .registerModule(new JavaTimeModule())

Deep-copying objects via Jackson serialization

serialization deep-copy generics

Intermediate 7 steps

ruby

module DeepImmutable
  module_function
 
  def deep_freeze(obj)

Deep-freezing config with recursive immutability

immutability recursion deep-copy

Intermediate 8 steps

go

package deepcopy
 
import (
	"bytes"

Deep copying any value with gob in Go

deep-copy serialization generics

Intermediate 6 steps

javascript

export function cloneState(state) {
  if (typeof structuredClone !== "function") {
    throw new Error("structuredClone is not available in this runtime");
  }

Deep cloning with structuredClone

deep-copy error-handling immutability

Intermediate 7 steps

typescript

type CloneInput = Record<string, unknown> | unknown[] | Map<unknown, unknown> | Set<unknown>;
 
export function deepClone<T>(value: T): T {
  if (typeof structuredClone === "function") {

Building a deepClone with cycle safety

recursion deep-copy cycle-detection

Intermediate 8 steps