Implementing a Deep Copy Function in Go

This challenge focuses on implementing a robust deep copy mechanism in Go. A deep copy creates an entirely new, independent copy of a data structure, including all nested structures. This is crucial for scenarios where you need to modify a copy of data without affecting the original, preventing unintended side effects.

Problem Description

Your task is to create a Go function, DeepCopy, that takes an arbitrary Go value (of any type) and returns a new value that is a deep copy of the input. This function should correctly handle various Go data types, including primitive types, pointers, slices, maps, structs, and their nested combinations.

Key Requirements:

• Handle Primitive Types: Integers, floats, booleans, strings should be copied directly.
• Handle Pointers: If the input is a pointer, the function should allocate new memory and copy the pointed-to value. If the pointer is nil, the returned pointer should also be nil.
• Handle Slices: Slices should be copied by creating a new slice and then deep copying each element.
• Handle Maps: Maps should be copied by creating a new map and then deep copying both keys and values.
• Handle Structs: Structs should be copied by creating a new struct and then deep copying each of its fields.
• Recursive Copying: The DeepCopy function must be recursive to handle nested data structures.
• Type Safety: The returned value should have the same type as the input value.
• Avoid Shared References: The deep copy must be entirely independent of the original. Modifying the copy should not affect the original, and vice-versa.

Expected Behavior:

Given an input value, the function should return a new value that is a complete, independent replica. This means that if you modify an element within a slice or a field within a struct of the copied value, the original value should remain unchanged.

Edge Cases to Consider:

• nil values for pointers, slices, and maps.
• Empty slices and maps.
• Recursive data structures (e.g., a struct containing a pointer to itself). This is a particularly challenging case.
• Types that are not directly copyable (e.g., channels, functions). Your implementation should handle these gracefully, perhaps by returning an error or a zero value for that type. For this challenge, we'll assume basic types, pointers, slices, maps, and structs.

Examples

Example 1:

Input: 123 (int)
Output: 123 (int)
Explanation: A simple integer is copied directly.

Example 2:

Input: `&Person{Name: "Alice", Age: 30, Address: &Address{Street: "123 Main St", City: "Anytown"}}` (pointer to a struct)
Output: `&Person{Name: "Alice", Age: 30, Address: &Address{Street: "123 Main St", City: "Anytown"}}` (a new, independent copy)
Explanation: The struct and its nested Address struct are copied. The returned value is a new pointer pointing to a new Person struct, which in turn points to a new Address struct.

Example 3:

Input: `[]int{1, 2, 3}` (slice of ints)
Output: `[]int{1, 2, 3}` (a new slice with copied elements)
Explanation: A new slice is created, and its elements are copied.

Example 4:

Input: `map[string]interface{}{"a": 1, "b": []int{4, 5}}` (map with mixed types)
Output: `map[string]interface{}{"a": 1, "b": []int{4, 5}}` (a new map with deep-copied values)
Explanation: A new map is created. The integer value for "a" is copied. The slice value for "b" is also deep-copied.

Example 5 (Recursive Structure): Consider a struct Node with a Next pointer to another Node:

type Node struct {
    Value int
    Next  *Node
}

Input: node1 := &Node{Value: 1, Next: &Node{Value: 2}} Output: A new Node structure that is a deep copy of node1, including the Next pointer and its recursively copied Node.

Constraints

• The DeepCopy function should accept an interface{} as input.
• The DeepCopy function should return an interface{}.
• The implementation should aim for reasonable performance. Avoid overly inefficient operations.
• For the purpose of this challenge, focus on handling the types mentioned in the "Problem Description." Handling channels, functions, or unexported fields is not strictly required but can be a bonus.

Notes

• Go's reflect package will be extremely useful for inspecting and manipulating values and types at runtime.
• Be mindful of cyclic data structures (like the recursive Node example). A naive recursive approach without cycle detection could lead to infinite recursion and a stack overflow. Consider how you might handle this.
• The standard library encoding/gob package offers a DeepCopy implementation. While you can't use it directly for this challenge, understanding its principles might be helpful.
• Success is measured by the function's ability to create truly independent copies across a range of Go data structures, including nested ones, and to handle nil values correctly.