Exit in Miranda

Here’s an idiomatic code example in Miranda that demonstrates the concept of exiting a program:

|| Exit function demonstration in Miranda

|| Define a function that simulates exiting with a status code
exit status = error ("Program exited with status " ++ show status)

|| Main function
main = exit 3

This Miranda code demonstrates the concept of exiting a program with a status code. Let’s break it down:

1. We define a function called exit that takes a status parameter. In Miranda, we don’t have direct access to system-level functions like os.Exit in Go, so we simulate the exit behavior using the error function.

2. The exit function constructs an error message using string concatenation (++) and the show function to convert the status code to a string.

3. In the main function, we call exit 3 to simulate exiting the program with status code 3.

To run this program:

1. Save the code in a file, for example, exit_demo.m.
2. Use the Miranda interpreter to run the program:

$ miranda exit_demo.m
Program exited with status 3

Program failed

Important notes about this Miranda example:

• Miranda doesn’t have a built-in way to exit the program with a specific status code like Go’s os.Exit. Instead, we use the error function to halt program execution and display a message.
• The error function in Miranda is used for runtime errors and will terminate the program execution.
• Unlike Go, Miranda doesn’t have the concept of deferred functions, so there’s no equivalent to demonstrate that deferred code won’t run.
• Miranda is a purely functional language, so side effects like exiting the program are typically modeled using functions that return special values or by using the error function as shown here.

This example provides a Miranda-specific approach to demonstrate the concept of program exit, adapting the idea to fit within Miranda’s functional programming paradigm and available language features.