The Dead-Simple Object Notation (DSON) Data Interchange Format {§=off}

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Abstract

Dead-Simple Object Notation (DSON) is a data interchange format intended to be intuitive, forgiving and human-readable. This standard is an attempt to define the simplest possible interchange format yet enough to describe complex nested structures.

{
  'Is DSON simple?' = true, # Indeed
  rules = [
    "non-ASCII, control and whitespace
      characters must be quoted",
  ]
}

General

Code point shortcuts used in the specification: {id=codepoints}

Code point	Shortcut
%x20 ( )	Whitespace
%x0a (LF), %x0d (CR), %x0d.0a (CRLF)	Newline
%x2c (,)	Comma

A comment begins with %x23 (#), consists of zero (excluding #) or more code points and is terminated with a newline. {id=comments}

Whitespaces and newlines are ignored outside of quoted strings and comments.

A value is a string, an object or an array.

A DSON file may contain a single object or array.

Strings

A string consists of zero or more code points and may be either quoted (§4.4) or unquoted (§4.3). A string consisting of zero code points is considered empty.

Any code point in a string may be escaped by prepending %x5c (\). An escaped code point is considered a part of the string. The \ itself may be escaped as \\.

Unquoted strings

An unquoted string is a string consisting of code points in range %x21-%x7e, excluding the following code points unless escaped:

• %x5b ([);
• %x5d (]);
• %x7b ({);
• %x7d (});
• %x2c (,).

An unquoted string is terminated with a comma.

An unquoted string is trimmed (i.e. whitespaces and newlines around it are removed). Therefore, an unquoted string consisting exclusively of whitespaces and newlines is considered empty.

Quoted strings

A quoted string is a string wrapped in a pair of unescaped quotes, i.e. %x22 (") or %x27 (').

Multiline strings

A multiline string is an unquoted string containing at least one newline.

A multiline string is aligned to the least-padded line, beginning from the second line.

A multiline string with the first line being empty has the first line ignored as if the string began from the second line.

A multiline string having a line ending with an escaped newline results in the following line appended to the previous one as if there was no newline.

Objects

An object begins with { and is terminated with }.

An object may contain zero or more comma-separated key-value pairs called object properties.

An object property key is a string.

An object property key must be unique within an object.

An object property key and value are separated with a single %x3d (=) code point.

Trailing commas are allowed, but can be omitted.

Arrays

An array begins with [ and is terminated with ].

An array may contain zero or more comma-separated values.

Trailing commas are allowed, but can be omitted.

Example

The following example is deliberately poorely formatted to demonstrate lenient-ness of the DSON format.

# The following DSON file contains # of settings
# for my program named "Foo"
{
  # Log settings
  log = {  # This is a nested DSON object!

     # Write into two streams (note
  # how the whitespace is escaped)
    path = ~/foo/bar.log\,\ $stdout,

    'level' =info, # 'warn' is the default level

    header= "
      A log file
     for my program\
   named \"Foo\"
    " # `···A·log·file\n··for·my·programnamed·"Foo"\n`
  },

  # File extensions to process
  extensions=[
    .jpg,
      '.💩', # Must be quoted, as it contains a Unicode point
] ,

    # A empty string
    exclude = ,

  # Also a empty string
  ignore =
}