Brief introduction

Documenting a large language like Raku has to balance several contradictory goals, such as being brief whilst being comprehensive, catering to professional developers with wide experience whilst also being accessible to newcomers to the language.

Note the recent name change to Raku from Perl 6 has resulted in some objects having changed names and their former names, while still available, are deprecated and their use is not recommended in new code. Those items are shown in the following table:

For a quick hands-on introduction, there is a short annotated programming example.

For programmers with experience in other languages, there are a number of Migration guides that compare and contrast the features of Raku with other languages.

A number of Tutorials cover several areas in which Raku is particularly innovative. The section headers should help navigate the remaining documents.

There are a number of useful resources listed elsewhere on the raku.org site. These include articles, books, slide presentations, and videos.

It has been found that newcomers to Raku often ask questions that indicate assumptions carried over from other programming paradigms. It is suggested that the following sections in the Fundamental topics section should be reviewed first.

• Signatures - each routine, which includes subroutines and methods, has a signature. Understanding the information given in the signature of a sub or method provides a quick way to grasp the operation and effect of the routine.

• Containers - variables, which are like the nouns of a computer language, are containers in which information is stored. The first letter in the formal name of a container, such as the '$' of $my-variable, or '@' of @an-array-of-things, or '%' of %the-scores-in-the-competition, conveys information about the container. However, Raku is more abstract than other languages about what can be stored in a container. So, for example, a $scalar container can contain an object that is in fact an array.

• Classes and Roles - Raku is fundamentally based on objects, which are described in terms of classes and roles. Raku, unlike some languages, does not impose object-oriented programming practices, and useful programs can be written as if Raku was purely procedural in nature. However, complex software, such as the Rakudo compiler of Raku, is made much simpler by writing in object-oriented idioms, which is why the Raku documentation is more easily understood by reviewing what a class is and what a role is. Without understanding about classes and roles, it would be difficult to understand types, to which a whole section of the documentation is devoted.

• Traps to Avoid - Several common assumptions lead to code that does not work as the programmer intended. This section identifies some of them. It is worth reviewing when something doesn't quite work out.