• 33. Appendix
• 35. Grammar

34. Conventions

Overview

These are the coding conventions we've used in the Fantom code base. By no means are you required to follow our conventions - they are documented just in case you care. However these conventions are enforced if contributing code for the core distribution.

Source Files

• Use 7-bit safe ASCII as clean subset of UTF-8
• Use Unix "\n" line endings
• Prefer putting class FooBar in a source file called "FooBar.fan"
• If you have a bunch of little classes, coalesce into a single source
• Separate test classes into separate "test/" directory

Naming

• Type names are upper camel case such as "FooBar"
• Slot names are lower camel case such as "fooBar" (this includes all fields and methods, even const fields)
• Never use screaming caps such as "FOO_BAR"
• Symbol names are lower camel case
• Pod names are lower camel case and globally unique. You should prefix your pod names with something to avoid naming conflicts. For example a SourceForge or Google Code project name is a safe naming convention. Or prefix pods with an organization or domain name. If you own a ".com" domain, don't include the "com" in your pod names.
• Don't use words which are fully capitalized in your identifiers:
  • Use "someId" instead of "someID"
  • Use "readXml" instead of "readXML"

Common Names

• Prefer add to append
• Prefer addr to address
• Prefer arg to argument
• Prefer cur to current
• Prefer dotnet/Dotnet
• Prefer err to error
• Prefer html/Html to HTML
• Prefer http/Http to HTTP
• Prefer id/Id to ID or Identifier
• Prefer io/IO to Io
• Prefer loc to location
• Prefer msg to message
• Prefer param to parameter
• Prefer rec to record
• Prefer req to request
• Prefer res to response
• Prefer res to resource
• Prefer ro/RO to Ro
• Prefer rw/RW to Rw
• Prefer size to length or count
• Prefer src to source
• Prefer username to userName
• Prefer val to value
• Prefer warn to warning
• Prefer xml/Xml to XML

Indention

• Do not use tab characters, use spaces only
• Use two space indention
• Use Allman styling braces:

  if (cond)
  {
    doTrue
  }
  else
  {
    doFalse
  }

• Prefer a single statement on each line with no semicolon
• Collapse statements onto a single line if they are short and it aids readability
• Leave one space between keyword and opening paren in if, for, while, switch, and catch statements

Statements

• Always omit () for method calls with no arguments
• Prefer Foo(...) style constructor with arguments
• Prefer Foo {...} style constructor when using it-block
• Prefer type inference for local variables
• Prefer implicit casting to explicit casting
• Prefer Obj[] to List and Obj:Obj to Map
• Prefer to omit return keyword in single statement methods and closures

Comments

• Use /* */ comments only for commenting out sections of code
• Prefer to use a leading and trailing ** line in a fandoc comment unless the comment is short:

  class Foo
  {
    **
    ** This is a very well written comment
    **
    Void doSomethingCool() {}
  }

• Break logical sections up using line of 74 / chars:

  //////////////////////////////////////////////////////////////////////////
  // Section
  //////////////////////////////////////////////////////////////////////////

• Use line of 74 * chars to separate classes in a single source file:

  **************************************************************************
  ** NewClass
  **************************************************************************

• We use the following comment at the top of each source file (obviously the names will be different for you):

  //
  // Copyright (c) 2008, Brian Frank and Andy Frank
  // Licensed under the Academic Free License version 3.0
  //
  // History:
  //   28 Aug 08  Brian Frank  Creation
  //

• 33. Appendix
• 35. Grammar