Replicating Go's iota in a Custom Implementation

Go's iota is a special constant generator that simplifies the creation of sequences of related constants. It's particularly useful for enumerations. This challenge asks you to implement a similar mechanism in Go, demonstrating your understanding of how such a feature could work.

Problem Description

Your task is to create a function or a mechanism in Go that mimics the behavior of iota. This means you need to generate a sequence of integer constants, starting from 0, where each subsequent constant increments by 1. You will then use this mechanism to define a set of enumerated types, similar to how you would use iota in standard Go.

Key Requirements:

• Implement a mechanism that automatically assigns sequential integer values to constants.
• The sequence should start from 0.
• Each subsequent constant should have a value one greater than the previous one.
• Demonstrate the usage of your custom iota with at least two different sets of enumerated constants.

Expected Behavior:

Your solution should allow you to define constants that are automatically assigned values like 0, 1, 2, 3, and so on, without explicitly assigning each value.

Edge Cases:

• Consider how your mechanism would behave if you want to skip values or assign specific values within the sequence. (Though the primary goal is sequential generation, understanding limitations is important). For this challenge, focus on the sequential generation.

Examples

Example 1: Status Codes

Let's say you want to define a set of status codes for a web application.

// Assuming your custom iota generator is named 'customIota'
const (
    StatusOK        = customIota() // Should be 0
    StatusCreated   = customIota() // Should be 1
    StatusBadRequest  = customIota() // Should be 2
    StatusInternalError = customIota() // Should be 3
)

Output of demonstrating these constants:

StatusOK: 0
StatusCreated: 1
StatusBadRequest: 2
StatusInternalError: 3

Example 2: Days of the Week

Another example using your custom iota for representing days of the week.

// Assuming your custom iota generator is named 'customIota'
const (
    Sunday    = customIota() // Should be 0
    Monday    = customIota() // Should be 1
    Tuesday   = customIota() // Should be 2
    Wednesday = customIota() // Should be 3
    Thursday  = customIota() // Should be 4
    Friday    = customIota() // Should be 5
    Saturday  = customIota() // Should be 6
)

Output of demonstrating these constants:

Sunday: 0
Monday: 1
Tuesday: 2
Wednesday: 3
Thursday: 4
Friday: 5
Saturday: 6

Constraints

• The core implementation of your customIota mechanism must generate sequential integers starting from 0.
• Your solution should be written entirely in Go.
• The solution should be demonstrably correct for at least two distinct sets of enumerated constants as shown in the examples.
• Avoid using complex reflection or external libraries that mimic iota directly. The goal is to understand the underlying principle.

Notes

Think about how iota is typically used within a const block. Go processes these blocks in a specific way. How can you leverage Go's constant declaration rules to achieve a similar effect? Consider what happens when you declare multiple constants within a single const block without explicit values.

Your primary goal is to reproduce the sequential assignment behavior. The ability to perform bitwise operations (like (1 << iota)) is a feature of Go's iota but not the primary focus of this challenge. Focus on the incrementing integer sequence.