Coding Style

Type names are PascalCased. For example:

Method names are snake_cased. For example:

  def first_name
  end
  def date_of_birth
  end
  def homepage_url
  end

Variable names are snake_cased. For example:

LUCKY_NUMBERS     = [3, 7, 11]
DOCUMENTATION_URL = "http://crystal-lang.org/docs"

In class names, acronyms are all-uppercase. For example, HTTP, and LibXML.

In method names, acronyms are all-lowercase. For example #from_json, #to_io.

Lib names are prefixed with . For example: LibC, LibEvent2.

• / contains a readme, any project configurations (eg, CI or editor configs), and any other project-level documentation (eg, changelog or contributing guide).
• src/ contains the project’s source code.
• spec/ contains the project’s specs, which can be run with crystal spec.
• bin/ contains any executables.

File paths match the namespace of their contents. Files are named after the class or namespace they define, with snake_case.

For example, HTTP::WebSocket is defined in src/http/web_socket.cr.

Indentation

Use two spaces to indent code inside namespaces, methods, blocks or other nested contexts. For example:

module Money
  CURRENCIES = {
    "EUR" => 1.0,
    "ARS" => 10.55,
    "USD" => 1.12,
    "JPY" => 134.15,
  }
    getter :currency, :value
    def initialize(@currency, @value)
    end
  end
  class CurrencyConversion
    def initialize(@amount, @target_currency)
    end
    def amount
      # implement conversion ...
    end
  end