@|c-enum-type| \- \\
@|c-pointer-type| \- \\
@|c-array-type| \\
- @|c-function-type|
+ @|c-function-type| \\ \ind
+ @|c-keyword-function-type| \-
\end{tabbing}}
\caption{Classes representing C types}
\label{fig:codegen.c-types.classes}
not return nil.
\end{describe}
-\begin{describe}{fun}{make-argument @<name> @<c-type> @> @<argument>}
+\begin{describe}{fun}
+ {make-argument @<name> @<c-type> \&optional @<default> @> @<argument>}
Construct and a return a new @<argument> object. The argument has type
@<c-type>, which must be a @|c-type| object, and is named @<name>.
suitable for function definitions. If @<name> is not nil, then the
@<name>'s print representation, with @|*print-escape*| nil, is used as the
argument name.
+
+ A @<default> may be supplied. If the argument is used in a
+ keyword-argument list (e.g., in a \descref{c-keyword-function-type}
+ [object]{cls}), and the @<default> value is provided and non-nil, then its
+ (unescaped) printed representation is used to provide a default value if
+ the keyword argument is not supplied by the caller.
\end{describe}
\begin{describe*}
{\dhead{fun}{argument-name @<argument> @> @<name>}
- \dhead{fun}{argument-type @<argument> @> @<c-type>}}
- Accessor functions for @|argument| objects. They return the name (for
- @|argument-name|) or type (for @|argument-type|) from the object, as passed
- to @|make-argument|.
+ \dhead{fun}{argument-type @<argument> @> @<c-type>}
+ \dhead{fun}{argument-default @<argument> @> @<default>}}
+ Accessor functions for @|argument| objects. They return the appropriate
+ component of the object, as set by to @|make-argument|. The @<default> is
+ nil if no default was provided to @|make-argument|.
\end{describe*}
\begin{describe}{gf}
\end{prog}
\end{describe}
+\begin{describe}{cls}
+ {c-keyword-function-type (c-function-type)
+ \&key :subtype :arguments :keywords}
+ Represents `functions' which accept keyword arguments. Of course, actual C
+ functions can't accept keyword arguments directly, but this type is useful
+ for describing messages and methods which deal with keyword arguments.
+
+ An instance denotes the type of C function which accepts the position
+ argument list @<arguments>, and keyword arguments from the @<keywords>
+ list, and returns @<subtype>. Either or both of the @<arguments> and
+ @<keywords> lists may be empty. (It is important to note the distinction
+ between a function which doesn't accept keyword arguments, and one which
+ does but for which no keyword arguments are defined. In particular, the
+ latter function can be changed later to accept a keyword argument without
+ breaking compatibility with old code.) The @<arguments> and @<keywords>
+ lists must \emph{not} contain @|:ellipsis| markers: a function can accept
+ keywords, or a variable-length argument tail, but not both.
+
+ Keyword arguments may (but need not) have a \emph{default value} which is
+ supplied to the function body if the keyword is omitted.
+
+ Keyword functions are never considered to be the same as ordinary
+ functions. Two keyword function types are considered to be the same if
+ their return types are the same, and their positional argument lists consist of
+ arguments with the same type, in the same order: the keyword arguments
+ accepted by the functions is not significant.
+
+ Keyword functions are constructed using an extended version of the @|fun|
+ specifier used for ordinary C function types. The extended syntax is as
+ follows.
+ \begin{prog}
+ (fun \=@<return-type>
+ @{ (@<arg-name> @<arg-type>) @}^* \+ \\
+ @{ \=:keys @{ (@<kw-name> @<kw-type> @[@<kw-default>@]) @}^*
+ @[. @<form>@] @! \+ \\
+ . @<form> @}
+ \end{prog}
+ where either the symbol @|:keys| appears literally in the specifier, or the
+ @<form> evaluates to a list containing the symbol @|:keys|. (If neither of
+ these circumstances obtains, then the specifier constructs an ordinary
+ function type.)
+
+ See the description of \descref{c-function-type}{cls} for how a trailing
+ @<form> is handled.
+
+ The list of @<arg-name>s and @<arg-type>s describes the positional
+ arguments. The list of @<kw-name>s, @<kw-type>s and @<kw-defaults>s
+ describes the keyword arguments.
+\end{describe}
+
\begin{describe}{fun}
{make-function-type @<subtype> @<arguments> @> @<c-function-type>}
Construct and return a new function type, returning @<subtype> and
accepting the @<arguments>.
+
+ If the @<arguments> list contains a @|:keys| marker, then a
+ \descref{c-keyword-function-type}[object]{cls} is returned: those arguments
+ preceding the @|:keys| marker form the positional argument list, and those
+ following the marker form the list of keyword arguments.
+\end{describe}
+
+\begin{describe}{fun}
+ {make-keyword-function-type @<subtype> @<arguments> @<keywords>
+ \nlret @<c-keyword-function-type>}
+ Construct and return a new keyword-function type, returning @<subtype> and
+ accepting the @<arguments> and @<keywords>.
\end{describe}
\begin{describe}{gf}
@|commentify-argument-names| to the argument list of the given type.
\end{describe}
+\begin{describe}{fun}{reify-variable-argument-tail @<arguments> @> @<list>}
+ If the @<argument> list contains an @|:ellipsis| marker, then replace it
+ with a @|va_list|. The name for the new argument, if any, is taken from
+ the \descref{*sod-ap*}[variable]{var}. The new list is returned; the
+ original list is not modified, but may share structure with the new list.
+\end{describe}
+
+\begin{describe}{fun}{merge-keyword-lists @<lists> @> @<list>}
+ Merge a number of keyword-argument lists together and return the result.
+
+ The @<lists> parameter is a list consisting of a number of @|(@<args>
+ . @<origin>)| pairs: in each pair, @<args> is a list of
+ \descref{argument}{cls} objects, and @<origin> is either nil or an object
+ whose printed representation describes the origin of the corresponding
+ @<args> list, suitable for inclusion in an error message.
+
+ The resulting list contains exactly one argument for each distinct argument
+ name appearing in the input @<lists>; this argument will contain the
+ default value from the earliest occurrence in the input @<lists> of an
+ argument with that name.
+
+ If the same name appears multiple times with different types, an error is
+ signalled quoting the name, conflicting types, and (if non-nil) the origins
+ of the offending argument objects.
+\end{describe}
+
\begin{describe}{fun}
{pprint-c-function-type @<return-type> @<stream>
@<print-args> @<print-kernel>}
~mdw / sod / blobdiff