Fluent Syntax 0.8

• Preserve content-indent in multiline Patterns. (#162)

  Multiline Patterns require to be indented by at least one space. In
  Syntax 0.7 all leading ident of every line was stripped. In Syntax 0.8
  only the maximum indent common to all indented lines is removed. This
  behavior works for all Patterns: in Messages, Terms, Attributes
  and Variants.

  multiline1 =
      This message has two spaces of indent
        on the second line of its value.

  This behavior also works when the first line of a block Pattern is
  indented relative to the following lines:

  multiline2 =
        This message has two spaces of indent
      on the first line of its value.

  Note that only indented lines participate in this behavior. Specifically,
  if a Pattern starts on the same line as the message identifier, then
  it's not considered as indented, and is excluded from the indent
  stripping.

  multiline3 = This message has two spaces of indent
        on the second line of its value. The first
      line is not considered indented at all.

  If a Pattern starts on the same line as the identifier, its first line
  is subject to the leading-whitespace stripping which is applied to all
  Patterns.

  # Same value as multiline3 above.
  multiline4 =     This message has two spaces of indent
        on the second line of its value. The first
      line is not considered indented at all.

  Note that if a multiline Pattern starts on the same line as the
  identifier and it only consists of one more line of text below it, then
  the maximum indent common to all indented lines is equal to the indent
  of the second line, i.e. the only indented line. All indent will be
  removed in this case. {" "} can be used to preserve it explicitly.

  multiline5 = This message has no indent
          on the second line of its value.

• Deprecate VariantLists. (#204)

  VariantLists and VariantExpression have been deprecated. They will be
  removed before Fluent 1.0 is released. Please use parameterized Terms
  instead (see below). Furthermore, in Syntax 0.8 it's not possible to nest
  VariantLists anymore (#220).

• Introduce parameterized Terms. (#176, #212)

  References to Terms can now receive parameters which will be used by
  the runtime as values of variables referenced from within the Term.
  This allows Terms to use regular Patterns as values, rather than
  VariantLists:

  # A Term with a VariantList as a value.
  -thing = {
     *[definite] the thing
      [indefinite] a thing
  }
  
  this = This is { -term[indefinite] }.

  # A parametrized Term with a Pattern as a value.
  -thing = { $article ->
     *[definite] the thing
      [indefinite] a thing
  }
  
  this = This is { -thing(article: "indefinite") }.

  Since Patterns can be nested, this feature allows more complex
  hierarchies of term values:

  # A parametrized Term with nested Patterns.
  -thing = { $article ->
     *[definite] { $first-letter ->
         *[lower] the thing
          [upper] The thing
      }
      [indefinite] { $first-letter ->
         *[lower] a thing
          [upper] A thing
      }
  }
  
  this = This is { -term(first-letter: "lower", article: "indefinite") }.

  Parameters must be named; positional parameters are ignored. If a
  parameter is omitted then the regular default variant logic applies. The
  above example could thus be written as {-term(article: "indefinite")}
  and the lower variant would be used because it is marked as the default
  one. If no parameters are specified, the paranthesis can be omitted:
  {-term()} and {-term} are functionally the same.

  Term attributes can be parameterized as well. To access them, use the
  -term.attr(param: "value") syntax.

• Support all Unicode characters in values. 🎉 (#174, #207)

  All Unicode characters can now be used in values of TextElements and
  StringLiterals, except those recognized as special by the syntax. Refer
  to spec/recommendations.md for information about character ranges which
  translation authors are encouraged to avoid.

• Don't store the - sigil in Identifiers of Terms. (#142)

  The - sigil is no longer part of the term's Identifier. This is now
  consistent with how Identifiers of variables don't include the $
  sigil either.

• Treat backslash (\) as a regular character in TextElements. (#123)

  Backslash does no longer have special escaping powers when used in
  TextElements. It's still recognized as special in StringLiterals,
  however. StringLiterals can be used to insert all special-purpose
  characters in text. For instance, {"{"} will insert the literal opening
  curly brace ({), {"\u00A0"} will insert the non-breaking space, and
  {" "} can be used to make a translation start or end with whitespace,
  which would otherwise by trimmed by Pattern.

• Forbid closing brace in TextElements. (#186)

  Both the opening and the closing brace are now considered special when
  present in TextElements. {"}"} can be used to insert a literal
  closing brace.

• Store both the raw and the unescaped value in StringLiteral. (#203)

  StringLiteral.value has been change to store the unescaped ("cooked")
  value of the string literal: all known escape sequences are replaced with
  the characters they represent. StringLiteral.raw has been added and
  stores the raw value as it was typed by the author of the string literal:
  escapes sequences are not processed in any way.

• Add the \UHHHHHH escape sequence. (#201)

  In addition to the already-supported \uHHHH escape sequence, \UHHHHHH
  is now also recognized and can be used to encode Unicode codepoints in the
  U+010000 to U+10FFFF range. For example, {"\U01F602"} can be used to
  represent 😂.

• Don't normalize line endings in Junk. (#184)

  Junk represents a literal slice of unparsed content and shouldn't have
  its line endings normalized to LF.

• Add the FunctionReference production. (#210)

  Function references in CallExpressions are now stored as
  FunctionReference AST nodes, with an id field which is an
  Identifier.

  The Function production and its corresponding AST node have been
  removed. The logic validating that function names are all upper-case has
  been moved to abstract.mjs.