Language

This chapter is the core language guide and reference.

It is organized around common programming tasks rather than around a taxonomy of language features. The early sections are the things most people need first. The later sections go deeper into Acton-specific parts of the language such as actors, concurrency, and capabilities.

What to read first

If you are new to Acton, read in this order:

1. Common programming concepts
2. Collections and everyday data
3. Missing values and failures
4. Modeling data and interfaces
5. Organizing code
6. Working with types
7. Actors & concurrency
8. Environment and capabilities

How to use this chapter as reference

• Use the book's search when you want to find a specific feature, keyword, or builtin quickly. This chapter is organized for reading and programming tasks, not as a strict feature index.
• Use section landing pages for overview.
• Use subpages for details and examples.
• Use the beginner and advanced callouts to choose the level of detail you need.
• For runtime and tooling behavior, see the chapters after Language (Testing, Build System, Package Management, and RTS).