Book Image

Learn Red ? Fundamentals of Red

By : Ivo Balbaert
Book Image

Learn Red ? Fundamentals of Red

By: Ivo Balbaert

Overview of this book

A key problem of software development today is software bloat, where huge toolchains and development environments are needed in software coding and deployment. Red significantly reduces this bloat by offering a minimalist but complete toolchain. This is the first introductory book about it, and it will get you up and running with Red as quickly as possible. This book shows you how to write effective functions, reduce code redundancies, and improve code reuse. It will be helpful for new programmers who are starting out with Red to explore its wide and ever-growing package ecosystem and also for experienced developers who want to add Red to their skill set. The book presents the fundamentals of programming in Red and in-depth informative examples using a step-by-step approach. You will be taken through concepts and examples such as doing simple metaprogramming, functions, collections, GUI applications, and more. By the end of the book, you will be fully equipped to start your own projects in Red.
Table of Contents (13 chapters)
11
Assessments

Getting input from the user – input and ask

The easiest way to get an input is to use the input word, as shown in the following code snippet:

;-- see Chapter04/getting-input.red:
print "Enter a number: "
num: input
print ["You entered the number" num "with" length? num "digits"]

When interpreted with the console through red getting-input.red or from within the console with do %getting-input.red, we get the following result when the number 89 is entered:

Enter a number:
89
You entered the number 89 with 2 digits

What is the datatype of num? If we try length? 89 in the console, we get a *** Script Error: length? does not allow integer! for its series argument. But length? "89" returns 2, so num must be of a string! type. Indeed, anything typed into the console is received by Red as a string. This is so for the input word, and...