Naming

Acton has naming rules and conventions. Some are enforced by the compiler, and some are conventions that keep larger programs readable.

Functions

Use lower-case words with _ between them.

• parse_user
• load_config
• send_report

Function names should describe what the function does.

Actors and classes

Use PascalCase with two or more alphanumeric characters.

• HttpServer
• OrderBook
• FileCache

Do not use a single upper-case letter for a class or actor name. Those names are reserved for type variables.

Type variables

Type variables use a single upper-case letter, optionally followed by digits.

• A
• T1

Use them for generic code, not for ordinary domain concepts. If a name describes a real thing in the program, make it a normal type or actor name instead.

Modules and files

Module names come from file paths, so filename choice matters. Use short, lower-case names and let the import path reflect the structure of src/. For example, src/a/b.act is imported as import a.b.

Naming is part of API design. In Acton, a module name, an imported symbol, and a type name often appear together, so keeping them short and predictable reduces noise in the code. This matters even more once a project has several modules and cross-module dependencies.

Private names

A leading _ is the usual marker for implementation details that should not be treated as part of the public surface. Use it for names that are only meant to be used inside one module or actor.

Practical guidance

• Prefer names that describe what a thing is or does.
• Use the same word for the same concept across modules.
• Avoid abbreviations unless they are standard in your domain.
• Make helper names specific enough that call sites read naturally.