The word “source” in the term “source code file” implies that the file contains the source/origin of the instructions in that code file.

Most code files are indeed the source/origin of the instructions in that code file. That is, for such files, a human enters and edits the instructions in the source code file using a text editor.

For most all computer software, the instructions in a source code file go through one or more conversions between when the human enters and edits those instructions and those instructions are implemented by the computer.

For example, for computer software that originates with C++ code files, even though this is not seen by the programmer by default, the C++ code file is converted to an Assembly code file which is then converted to an Object code file before it is implemented by the computer.

In this scenario, the Assembly code file contain instructions that implement the same functioning and logic as the C++ code file, and is still called an Assembly source code file, even though the Assembly code file is not the source/origin of the instructions. Indeed, there is some software in which a human enters and edits the instructions in an Assembly code file using a text editor. Therefore, Assembly code can be either source code or target code.

In this scenario, a production that contains Assembly code generated from C++ code, but does not contain the original C++ code, would not be a source code production.

Further, even code files that are almost always entered and edited by humans are sometimes generated by other software.

For example, a C++ code file can be generated by the ProtoBuf tool from a file in the .proto format. Therefore, while C++ code files are most always referred to as source code files, the origin/source of the instructions in this scenario is the file in the .proto format. In this scenario, a production that contains C++ code generated from .proto files, but does not contain the original .proto files, would not be a source code production.

Artificial Intelligence as the source of code

Some modern AI tools can generate code. For example, I gave ChatGPT 3.5 the prompt, “Please generate a collection of C++ functions which implement a double-linked list.” In response to this prompt, ChatGPT 3.5 generated the C++ code at the end of this post.

Since ChatGPT 3.5 learned from one or more fragments of C++ code that existed somewhere on the Internet in 2021, what is the source of the code at the end of this post?

• Is the source simply the generated code below?
• Is the source the fragments of practically anonymous code used to train ChatGPT 3.5?
• Is the source my prompt?

There are yet to be legally-tested definitions of the source of code generated by AI agents.

#include <iostream>

template <typename T>
class Node {
public:
    T data;
    Node* next;
    Node* prev;

    Node(T value) : data(value), next(nullptr), prev(nullptr) {}
};

template <typename T>
class DoublyLinkedList {
private:
    Node<T>* head;
    Node<T>* tail;

public:
    DoublyLinkedList() : head(nullptr), tail(nullptr) {}

    ~DoublyLinkedList() {
        clear();
    }

    void insertFront(T value) {
        Node<T>* newNode = new Node<T>(value);
        if (!head) {
            head = tail = newNode;
        } else {
            newNode->next = head;
            head->prev = newNode;
            head = newNode;
        }
    }

    void insertEnd(T value) {
        Node<T>* newNode = new Node<T>(value);
        if (!tail) {
            head = tail = newNode;
        } else {
            newNode->prev = tail;
            tail->next = newNode;
            tail = newNode;
        }
    }

    void remove(T value) {
        Node<T>* current = head;

        while (current && current->data != value) {
            current = current->next;
        }

        if (!current) {
            std::cout << "Element not found in the list.\n";
            return;
        }

        if (current->prev) {
            current->prev->next = current->next;
        } else {
            head = current->next;
        }

        if (current->next) {
            current->next->prev = current->prev;
        } else {
            tail = current->prev;
        }

        delete current;
    }

    void displayForward() {
        Node<T>* current = head;
        while (current) {
            std::cout << current->data << " ";
            current = current->next;
        }
        std::cout << std::endl;
    }

    void displayBackward() {
        Node<T>* current = tail;
        while (current) {
            std::cout << current->data << " ";
            current = current->prev;
        }
        std::cout << std::endl;
    }

    void clear() {
        while (head) {
            Node<T>* temp = head;
            head = head->next;
            delete temp;
        }
        tail = nullptr;
    }
};

int main() {
    DoublyLinkedList<int> myList;

    myList.insertFront(3);
    myList.insertFront(2);
    myList.insertEnd(4);
    myList.displayForward(); // Output: 2 3 4
    myList.displayBackward(); // Output: 4 3 2

    myList.remove(3);
    myList.displayForward(); // Output: 2 4

    myList.clear(); // Clean up memory

    return 0;
}