\begin{grammar}
<code-definition> ::=
- "code" <identifier> ":" <identifier> @[<constraints>@]
+ "code" <identifier> ":" <item-name> @[<constraints>@]
"{" <c-fragment> "}"
<constraints> ::= "[" <list>$[\mbox{@<constraint>}]$ "]"
-<constraint> ::= @<identifier>^+
+<constraint> ::= @<item-name>^+
+
+<item-name> ::= <identifier> @! "(" @<identifier>^+ ")"
\end{grammar}
The @<c-fragment> will be output unchanged to one of the output files.
output file names are @"c" and @"h", which are the implementation code and
header file respectively; other output files can be defined by extensions.
-The second @<identifier> provides a name for the output item. Several C
-fragments can have the same name: they will be concatenated together in the
-order in which they were encountered.
+Output items are named with a sequence of identifiers, separated by
+whitespace, and enclosed in parentheses. As an abbreviation, a name
+consisting of a single identifier may be written as just that identifier,
+without the parentheses.
The @<constraints> provide a means for specifying where in the output file
the output item should appear. (Note the two kinds of square brackets shown
in the syntax: square brackets must appear around the constraints if they are
present, but that they may be omitted.) Each comma-separated @<constraint>
-is a sequence of identifiers naming output items, and indicates that the
-output items must appear in the order given -- though the translator is free
-to insert additional items in between them. (The particular output items
-needn't be defined already -- indeed, they needn't be defined ever.)
+is a sequence of names of output items, and indicates that the output items
+must appear in the order given -- though the translator is free to insert
+additional items in between them. (The particular output items needn't be
+defined already -- indeed, they needn't be defined ever.)
There is a predefined output item @"includes" in both the @"c" and @"h"
output files which is a suitable place for inserting @"\#include"
\alt "bool" | "_Bool"
\alt "imaginary" | "_Imaginary" | "complex" | "_Complex"
\alt <qualifier>
+\alt <storage-specifier>
+\alt <atomic-type>
+
+<qualifier> ::= <atomic> | "const" | "volatile" | "restrict"
+
+<atomic-type> ::=
+ <atomic> "(" @<declaration-specifier>^+ <abstract-declarator> ")"
+
+<atomic> ::= "atomic" | "_Atomic"
-<qualifier> ::= "const" | "volatile" | "restrict"
+<storage-specifier> ::= <alignas> "(" <c-fragment> ")"
+
+<alignas> ::= "alignas" "_Alignas"
<type-name> ::= <identifier>
\end{grammar}
Declaration specifiers may appear in any order. However, not all
combinations are permitted. A declaration specifier must consist of zero or
-more @<qualifiers>, and one of the following, up to reordering.
+more @<qualifier>s, zero or more @<storage-specifier>s, and one of the
+following, up to reordering.
\begin{itemize}
\item @<type-name>
+\item @<atomic-type>
\item @"struct" @<identifier>, @"union" @<identifier>, @"enum" @<identifier>
\item @"void"
\item @"_Bool", @"bool"
\subsubsection{Declarators}
\begin{grammar}
-<declarator>$[k]$ ::= @<pointer>^* <primary-declarator>$[k]$
+<declarator>$[k, a]$ ::= @<pointer>^* <primary-declarator>$[k, a]$
-<primary-declarator>$[k]$ ::= $k$
-\alt "(" <primary-declarator>$[k]$ ")"
-\alt <primary-declarator>$[k]$ @<declarator-suffix>
+<primary-declarator>$[k, a]$ ::= $k$
+\alt "(" <primary-declarator>$[k, a]$ ")"
+\alt <primary-declarator>$[k, a]$ @<declarator-suffix>$[a]$
<pointer> ::= "*" @<qualifier>^*
-<declarator-suffix> ::= "[" <c-fragment> "]"
-\alt "(" <arguments> ")"
+<declarator-suffix>$[a]$ ::= "[" <c-fragment> "]"
+\alt "(" $a$ ")"
<argument-list> ::= $\epsilon$ | "..."
\alt <list>$[\mbox{@<argument>}]$ @["," "..."@]
<argument> ::= @<declaration-specifier>^+ <argument-declarator>
-<argument-declarator> ::= <declarator>$[\mbox{@<identifier> @! $\epsilon$}]$
+<abstract-declarator> ::= <declarator>$[\epsilon, \mbox{@<argument-list>}]$
-<simple-declarator> ::= <declarator>$[\mbox{@<identifier>}]$
+<argument-declarator> ::= <declarator>$[\mbox{@<identifier> @! $\epsilon$}]$
+<argument-declarator> ::=
+ <declarator>$[\mbox{@<identifier> @! $\epsilon$}, \mbox{@<argument-list>}]$
-<dotted-name> ::= <identifier> "." <identifier>
+<simple-declarator> ::=
+ <declarator>$[\mbox{@<identifier>}, \mbox{@<argument-list>}]$
\end{grammar}
The declarator syntax is taken from C, but with some differences.
The remaining differences are (I hope) a matter of presentation rather than
substance.
+There is additional syntax to support messages and methods which accept
+keyword arguments.
+
+\begin{grammar}
+<keyword-argument> ::= <argument> @["=" <c-fragment>@]
+
+<keyword-argument-list> ::=
+ @[<list>$[\mbox{@<argument>}]$@]
+ "?" @[<list>$[\mbox{@<keyword-argument>}]$@]
+
+<method-argument-list> ::= <argument-list> @! <keyword-argument-list>
+
+<dotted-name> ::= <identifier> "." <identifier>
+
+<keyword-declarator>$[k]$ ::=
+ <declarator>$[k, \mbox{@<method-argument-list>}]$
+\end{grammar}
+
\subsection{Class definitions} \label{sec:syntax.module.class}
<class-item> ::= <slot-item>
\alt <initializer-item>
+\alt <initarg-item>
+\alt <fragment-item>
\alt <message-item>
\alt <method-item>
\end{grammar}
\begin{grammar}
<initializer-item> ::= @["class"@] <list>$[\mbox{@<slot-initializer>}]$ ";"
-<slot-initializer> ::= <dotted-name> "=" <initializer>
+<slot-initializer> ::= <dotted-name> @["=" <initializer>@]
-<initializer> :: "{" <c-fragment> "}" | <c-fragment>
+<initializer> :: <c-fragment>
\end{grammar}
An @<initializer-item> provides an initial value for one or more slots. If
class's superclasses (including itself); the second must be the name of a
slot defined in that superclass.
-The initializer has one of two forms.
-\begin{itemize}
-\item A @<c-fragment> enclosed in braces denotes an aggregate initializer.
- This is suitable for initializing structure, union or array slots.
-\item A @<c-fragment> \emph{not} beginning with an open brace is a `bare'
- initializer, and continues until the next @`,' or @`;' which is not within
- nested brackets. Bare initializers are suitable for initializing scalar
- slots, such as pointers or integers, and strings.
-\end{itemize}
+An @|initarg| property may be set on an instance slot initializer (or a
+direct slot definition). See \xref{sec:concepts.lifecycle.birth} for the
+details. An initializer item must have either an @|initarg| property, or an
+initializer expression, or both.
+
+Each class may define at most one initializer item with an explicit
+initializer expression for a given slot.
+
+\subsubsection{Initarg items}
+\begin{grammar}
+<initarg-item> ::=
+ "initarg"
+ @<declaration-specifier>^+
+ <list>$[\mbox{@<init-declarator>}]$ ";"
+\end{grammar}
+
+\subsubsection{Fragment items}
+\begin{grammar}
+<fragment-item> ::= <fragment-kind> "{" <c-fragment> "}"
+
+<fragment-kind> ::= "init" | "teardown"
+\end{grammar}
\subsubsection{Message items}
\begin{grammar}
~mdw / sod / blobdiff