Abstract

Although Nimrod, through its flexible AST and case-sensitivity settings, supports a variety of code and formatting styles, it is nevertheless beneficial that certain community efforts, such as the standard library, should follow a consistent set of style guidelines when suitable. This enhancement proposal aims to list a series of guidelines that the standard library should follow. Note that these are guidelines only. The nature of Nimrod being as flexible as it is, there will be parts of this style guide that don't make sense in certain contexts. Furthermore, just as Python's style guide changes over time, this style guide will too.

Style Guidelines

General

Type identifiers should be in CamelCase. All other identifiers should be in pascalCase.
```
const aConstant = 42

var aVariable = "Meep"

type FooBar = object
```
Members of enums should have an identifying prefix, such as an abbreviation of the enum's name.
```
type PathComponent = enum
  pcDir
  pcLinkToDir
  pcFile
  pcLinkToFile
```
Lines should be no longer than 80 characters
2 spaces should be used for indentation. Although one can use tabstops for indentation through use of template filters, this considered an unnecessary hack.
The 'return' statement should only be used when it's control-flow properties are required. Use a procedures implicit 'result' variable instead. Using the implicit result variables allows both the Nimrod compiler and its various backends to perform special optimizations
Use the 'let' statement (not the var statement) when declaring variables that do not change within their scope. Using the let statement ensures that variables remain immutable, and gives those who read the code a better idea of the code's purpose.
Any tuple type declarations that are longer than one line should use the regular object type layout instead. This enhances the readability of the tuple declaration by splitting its members information across multiple lines.
```
type
  ShortTuple = tuple[a: int, b: string]

  ReallyLongTuple = tuple
    wordyTupleMemberOne: string
    wordyTupleMemberTwo: int
    wordyTupleMemberThree: double
```
Similarly, any procedure type declarations that are longer than one line should be formatted in the style of a regular type.
```
type
  EventCallback = proc (
    timeRecieved: TTime
    errorCode: int
    event: Event
  )
```
Multi-line procedure declarations/argument lists should continue on the same column as the opening brace. This style is different from that of procedure type declarations in order to distinguish between the heading of a procedure and its body.
```
proc lotsOfArguments(argOne: string, argTwo: int, argThree:float
                     argFour: proc(), argFive:bool): int
```

Multi-line procedure calls should either have one argument per line (like multi-line type declarations) or continue on the same column as the opening parenthesis (like multi-line procedure declarations). It is suggested that the former style be used for procedure calls with complex argument structures, and the latter style for procedure calls with simpler argument structures.

# Each argument on a new line, like type declarations
# Best suited for 'complex' procedure calls.
readDirectoryChangesW(
  directoryHandle.THandle,
  buffer.start,
  bufferSize.int32,
  watchSubdir.WinBool,
  filterFlags,
  cast[ptr dword](nil),
  cast[POverlapped](ol),
  cast[LPOverlappedCompletionRoutine](nil)
)


# Multiple arguments on new lines, aligned to the opening parenthesis
# Best suited for 'simple' procedure calls
startProcess(nimrodExecutable, currentDirectory, compilerArguments
             environment, processOptions)

Use of extra whitespace for alignment is discouraged. This is not necessarily because such a alignment is bad, but because of the varying support editors have for auto-alignment of text, and the fact that manual alignment and re-alignment can be quite time consuming.

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Abstract

Style Guidelines

General

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