Scheme is a popular programming language that was originally designed at the Massachusetts Institute of Technology (MIT) in the 1970s. Scheme is a dialect of Lisp, a family of programming languages that emphasizes the use of lists and recursion. Scheme is known for its simplicity, elegance, and expressiveness, which makes it a popular choice for both teaching and research.
How to Write Scheme Code
Scheme code is written in plain text files with the extension ".scm". To write Scheme code, you will need a text editor, such as Emacs or Vim, and a Scheme interpreter, such as GNU Guile or MIT Scheme.
Here is an example of a simple Scheme program that prints "Hello, world!" to the console:
```scheme
(display "Hello, world!")
```
To run this program, save it in a file named "hello.scm", and then load it into your Scheme interpreter using the "load" command:
```
(load "hello.scm")
```
This will execute the program and display the message "Hello, world!" on the console.
Scheme Syntax
Scheme has a simple and consistent syntax that makes it easy to read and write code. Scheme code is made up of expressions, which are evaluated by the interpreter to produce a value.
Here is an example of a Scheme expression that computes the factorial of a number:
```scheme
(define (factorial n)
(if (= n 0)
1
(* n (factorial (- n 1)))))
```
This defines a function called "factorial" that takes a single argument "n" and computes the factorial of that number. The expression uses the "if" construct to check if "n" is equal to 0, and if so, returns 1. Otherwise, it multiplies "n" by the result of calling "factorial" on "n - 1".
Best Applications for Scheme
Scheme is a versatile language that can be used for a variety of applications, including:
1. Teaching programming: Scheme's simplicity and elegance make it an ideal language for teaching programming concepts and techniques.
2. Research: Scheme is often used in research projects, particularly in the fields of artificial intelligence and computer science.
3. Web development: Scheme can be used to develop web applications using frameworks such as Chicken Scheme and Web Server Gateway Interface (WSGI).
4. Scripting: Scheme can be used as a scripting language for automating tasks and system administration.
Conclusion
Scheme is a powerful and elegant programming language that is easy to learn and use. With its simple syntax and consistent semantics, Scheme is a great language for both teaching and research. Its versatility makes it suitable for a wide range of applications, from web development to system administration. We hope this beginner's guide has given you a good introduction to Scheme programming language and inspired you to try it out for yourself.