not specified, clients may still not rely on receiving fresh objects.
A convenient S-expression notation is provided by the
-\descref{c-type}[macro]{mac}. Use of this macro is merely an abbreviation
+\descref{mac}{c-type}[macro]. Use of this macro is merely an abbreviation
for corresponding use of the various constructor functions, and therefore
interns type objects in the same manner. The syntax accepted by the macro
-can be extended in order to support new classes: see \descref{defctype}{mac},
-\descref{c-type-alias}{mac} and \descref{define-c-type-syntax}{mac}.
+can be extended in order to support new classes: see \descref{mac}{defctype},
+\descref{mac}{c-type-alias} and \descref{mac}{define-c-type-syntax}.
The descriptions of each of the various classes include descriptions of the
initargs which may be passed to @|make-instance| when constructing a new
There are two protocols for printing C types. Unfortunately they have
similar names.
\begin{itemize}
-\item The \descref{print-c-type}[function]{gf} prints a C type value using
+\item The \descref{gf}{print-c-type}[function] prints a C type value using
the S-expression notation. It is mainly useful for diagnostic purposes.
-\item The \descref{pprint-c-type}[function]{gf} prints a C type as a
+\item The \descref{gf}{pprint-c-type}[function] prints a C type as a
C-syntax declaration.
\end{itemize}
Neither generic function defines a default primary method; subclasses of
\begin{describe}{gf}{expand-c-type-spec @<type-spec> @> @<form>}
Returns the Lisp form that @|(c-type @<type-spec>)| would expand into.
- If @<type-spec> is a list, then \descref{expand-c-type-form}{gf} is
+ If @<type-spec> is a list, then \descref{gf}{expand-c-type-form} is
invoked.
\end{describe}
directly attached. If the @<kernel> function intends to provide its own
additional declarator operators, it should check the @<priority> in order
to determine whether parentheses are necessary. See also the
- \descref{maybe-in-parens}[macro]{mac}.
+ \descref{mac}{maybe-in-parens}[macro].
The @<spacep> argument indicates whether a space needs to be printed in
order to separate the declarator from the declaration specifiers. A kernel
which contains an identifier should insert a space before the identifier
when @<spacep> is non-nil. An `empty' kernel, as found in an abstract
declarator (one that specifies no name), looks more pleasing without a
- trailing space. See also the \descref{c-type-space}[function]{fun}.
+ trailing space. See also the \descref{fun}{c-type-space}[function].
Every concrete subclass of @|c-type| is expected to provide a primary
method on this function. There is no default primary method.
The default behaviour, on output, is to convert keywords to lowercase and
hope for the best: special cases can be dealt with by adding appropriate
-methods to \descref{c-qualifier-keyword}{gf}.
+methods to \descref{gf}{c-qualifier-keyword}.
\begin{describe}{cls}{qualifiable-c-type (c-type) \&key :qualifiers}
The class @|qualifiable-c-type| describes C types which can bear
evaluated).
Each of the @<string>s is associated with the resulting type for retrieval
- by \descref{find-simple-c-type}{fun}. Furthermore, a variable
+ by \descref{fun}{find-simple-c-type}. Furthermore, a variable
@|c-type-@<name>| is defined, for the first @<name> only, and initialized
with the newly constructed C type object.
\begin{describe}{fun}
{find-simple-c-type @<string> @> @{ @<simple-c-type> @! @|nil| @}}
If @<string> is the name of a simple C type, as established by the
- \descref{define-simple-c-type}[macro]{mac}, then return the corresponding
+ \descref{mac}{define-simple-c-type}[macro], then return the corresponding
@|simple-c-type| object; otherwise, return @|nil|.
\end{describe}
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
+ keyword-argument list (e.g., in a \descref{cls}{c-keyword-function-type}
+ [object]), 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}
these circumstances obtains, then the specifier constructs an ordinary
function type.)
- See the description of \descref{c-function-type}{cls} for how a trailing
+ See the description of \descref{cls}{c-function-type} for how a trailing
@<form> is handled.
The list of @<arg-name>s and @<arg-type>s describes the positional
accepting the @<arguments>.
If the @<arguments> list contains a @|:keys| marker, then a
- \descref{c-keyword-function-type}[object]{cls} is returned: those arguments
+ \descref{cls}{c-keyword-function-type}[object] 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}{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
+ the \descref{var}{*sod-ap*}[variable]. The new list is returned; the
original list is not modified, but may share structure with the new list.
\end{describe}
The @<lists> parameter is a list consisting of a number of
@|(@<report-function> . @<args>)| pairs: in each pair, @<report-function>
is either nil or a function designator, and @<args> is a list of
- \descref{argument}{cls} objects.
+ \descref{cls}{argument} objects.
The resulting list contains exactly one argument for each distinct argument
name appearing in the input @<lists>; this argument will contain the
arguments and is expected to return two values:
\begin{itemize}
\item a file location @<floc> or other object acceptable to
- \descref{file-location}{gf}, to be used as the location of the main
+ \descref{gf}{file-location}, to be used as the location of the main
error; and
\item an object @<what>, whose printed representation should be a noun
phrase describing the object for which the argument lists are being
for the @<args> lists containing the conflicting argument objects are
called, in an arbitrary order, with a single argument which is the
offending @|argument| object; the function is expected to issue information
- messages (see \descref{info}{fun}) to give more detail for diagnosing the
+ messages (see \descref{fun}{info}) to give more detail for diagnosing the
conflict. If a @<report-function> is nil, then nothing happens; this is
considered poor practice.
\end{describe}
arguments, if any, will be printed by @<print-args>.
The @<print-kernel> function is a standard kernel-printing function
- following the \descref{pprint-c-type}[protocol]{gf}.
+ following the \descref{gf}{pprint-c-type}[protocol].
The @<print-args> function is given a single argument, which is the
@<stream> to print on. It should not print the surrounding parentheses.
\begin{describe}{fun}{pprint-argument-list @<args> @<stream> @> @<flag>}
Print an argument list to @<stream>.
- The @<args> is a list of \descref{argument}[objects]{cls}, optionally
+ The @<args> is a list of \descref{cls}{argument}[objects], optionally
containing an @|:ellipsis| marker. The function returns true if any
arguments were actually printed.
\end{describe}
a lookup at runtime to find the appropriate offset by which to adjust the
pointer. The conversion can be performed using the appropriate generated
upcast macro (see below); the general case is handled by the macro
- \descref{SOD_XCHAIN}{mac}.
+ \descref{mac}{SOD_XCHAIN}.
\item If $B$ is a subclass of~$C$ then the conversion is a \emph{downcast};
otherwise the conversion is a~\emph{cross-cast}. In either case, the
conversion can fail: the object in question might not be an instance of~$B$
- after all. The macro \descref{SOD_CONVERT}{mac} and the function
- \descref{sod_convert}{fun} perform general conversions. They return a null
+ after all. The macro \descref{mac}{SOD_CONVERT} and the function
+ \descref{fun}{sod_convert} perform general conversions. They return a null
pointer if the conversion fails. (These are therefore your analogue to the
\Cplusplus\ @|dynamic_cast<>| operator.)
\end{itemize}
instance's slots, and maybe links it into any external data structures as
necessary.
\end{enumerate}
-The \descref{SOD_DECL}[macro]{mac} handles constructing instances with
+The \descref{mac}{SOD_DECL}[macro] handles constructing instances with
automatic storage duration (`on the stack'). Similarly, the
-\descref{SOD_MAKE}[macro]{mac} and the \descref*{sod_make}{fun} and
-\descref{sod_makev}{fun} functions construct instances allocated from the
+\descref{mac}{SOD_MAKE}[macro] and the \descref*{fun}{sod_make} and
+\descref{fun}{sod_makev} functions construct instances allocated from the
standard @|malloc| heap. Programmers can add support for other allocation
-strategies by using the \descref{SOD_INIT}[macro]{mac} and the
-\descref*{sod_init}{fun} and \descref{sod_initv}{fun} functions, which
+strategies by using the \descref{mac}{SOD_INIT}[macro] and the
+\descref*{fun}{sod_init} and \descref{fun}{sod_initv} functions, which
package up imprinting and initialization.
\subsubsection{Allocation}
Teardown alone, for objects which require special deallocation, or for which
deallocation occurs automatically (e.g., instances with automatic storage
duration, or instances whose storage will be garbage-collected), is performed
-using the \descref{sod_teardown}[function]{fun}. Destruction of instances
+using the \descref{fun}{sod_teardown}[function]. Destruction of instances
allocated from the standard @|malloc| heap is done using the
-\descref{sod_destroy}[function]{fun}.
+\descref{fun}{sod_destroy}[function].
\subsubsection{Teardown}
Details of teardown are necessarily class-specific, but typically it
The code which makes the decision to destroy an object may often not be aware
of the object's direct class. Low-level details of deallocation often
require the proper base address of the instance's storage, which can be
-determined using the \descref{SOD_INSTBASE}[macro]{mac}.
+determined using the \descref{mac}{SOD_INSTBASE}[macro].
%%%--------------------------------------------------------------------------
\section{Metaclasses} \label{sec:concepts.metaclasses}
\dhead{gf}{merge-error-candidates @<error> @> @<list>}
\dhead{gf}{merge-error-present-function @<error> @> @<function>}}
The @|inconsistent-merge-error| condition class used to represent a failure
- of the \descref{merge-lists}[function]{fun}.
+ of the \descref{fun}{merge-lists}[function].
The @<candidates> are a list of offending items from the input lists, in
some order: the error is reporting that the function has failed because it
Assume that we are currently at a particular @<line> and @<column> in a
file, and wish to \emph{unread} @<character>: return an @<old-line> and
@<old-column> at which we might plausibly re-read the character, so that
- the next call to \descref{update-position}{fun} will return us to @<line>
+ the next call to \descref{fun}{update-position} will return us to @<line>
and @<column>. (Specifically, the @<old-column> will likely be wrong if
@<character> is a horizontal tab. It is expected that this won't matter:
the purpose of this function is to set things up so that the
The main purpose for this is to be able to access features of the
underlying stream which a pretty-printing stream can't proxy. Most
notably, this is used by C fragment output, which takes advantage of an
- underlying \descref{position-aware-output-stream}{cls} to print @|\#line|
+ underlying \descref{cls}{position-aware-output-stream} to print @|\#line|
directives, so that a C~compiler will blame the original fragment in the
Sod module source rather than the generated C code.
\end{describe}
\end{describe}
\begin{describe}{fun}{cerror* @<datum> \&rest @<arguments>}
- A simplified version of \descref{promiscuous-cerror}{fun} which uses the
+ A simplified version of \descref{fun}{promiscuous-cerror} which uses the
hardcoded string @|Continue| for the restart. This makes calling the
function more similar to other condition-signalling functions, at the
expense of some usability in environments which don't continue after
keyword names and argument values, as described above, including the first
keyword name. (This is therefore different from the convention used when
calling keyword argument parser functions: see the description of the
- \descref{KWSET_PARSEFN}[macro]{mac} for more details about these.) The
+ \descref{mac}{KWSET_PARSEFN}[macro] for more details about these.) The
argument tail may itself contain the special keywords.
\item[kw.tab] This special keyword is followed by \emph{two} argument values:
\item Omitting the null terminator is a common mistake, so @|<keyword.h>|
tries to get the compiler to warn if you miss it. However, the
- \descref{KWTAIL}[macro]{mac} introduces an extra real argument
+ \descref{mac}{KWTAIL}[macro] introduces an extra real argument
@|kwfirst_|, because it's not possible to scan a variable-length argument
tail if there are no mandatory arguments. If you use @|KWARGS()|, with
an empty argument list, then the null terminator is passed as @|kwfirst_|
*kwfirst_| (to collect the first keyword name), and a variable-length
argument tail.
- The \descref{KWPARSE}[macro]{mac} assumes that the enclosing function's
+ The \descref{mac}{KWPARSE}[macro] assumes that the enclosing function's
argument list ends with a @|KWTAIL| marker.
\end{describe}
The function also handles the special @|kw.valist| and @|kw.tab| arguments
described above (\xref{sec:runtime.keywords.calling}). If an unrecognized
- keyword argument is encountered, then \descref{kw_unknown}{fun} is called.
+ keyword argument is encountered, then \descref{fun}{kw_unknown} is called.
\end{describe}
\subsubsection{Parsing keywords}
final keyword argument; a null pointer; and the value zero (signifying an
empty keyword-argument vector).
- If the variable @<kw> was declared using \descref{KWDECL}{mac} and the
+ If the variable @<kw> was declared using \descref{mac}{KWDECL} and the
function @|@<set>{}_kwparse| has been defined using
- \descref{KWSET_PARSEFN}{mac} then the effect is to parse the keyword
+ \descref{mac}{KWSET_PARSEFN} then the effect is to parse the keyword
arguments passed to the function and set the members of @<kw>
appropriately.
\end{describe}
\begin{describe}{mac}[KWPARSE]{KWPARSE(@<set>);}
The macro @|KWPARSE| (note the lack of underscore) combines
- \descref{KWDECL}{mac} and \descref{KW_PARSE}{mac}. It declares and
+ \descref{mac}{KWDECL} and \descref{mac}{KW_PARSE}. It declares and
initializes a keyword argument structure variable with the fixed name
@|kw|, and parses the keyword arguments provided to the enclosing function,
storing the results in @|kw|. It assumes that the first keyword name is in
an argument named @|kwfirst_|, as set up by the
- \descref{KWTAIL}[marker]{mac}.
+ \descref{mac}{KWTAIL}[marker].
The macro expands both to a variable declaration and a statement: in C89,
declarations must precede statements, so under C89 rules this macro must
\end{describe}
As mentioned above, it is not permitted to define an empty keyword set.
-(Specifically, invoking \descref{KWSET_STRUCT}{mac} for an empty keyword set
+(Specifically, invoking \descref{mac}{KWSET_STRUCT} for an empty keyword set
would result in attempting to define a structure with no members, which C
doesn't allow.) On the other hand, keyword arguments are a useful extension
mechanism, and it's useful to be able to define a function which doesn't
allow keyword arguments.
\begin{describe}{mac}[KW_PARSE_EMPTY]{KW_PARSE_EMPTY(@<set>, @<kwfirst>);}
- This is an analogue to \descref{KW_PARSE}{mac} which checks the keyword
+ This is an analogue to \descref{mac}{KW_PARSE} which checks the keyword
argument list for a function which accepts no keyword arguments.
- It calls the \descref{kw_parseempty}[function]{fun} with five arguments:
+ It calls the \descref{fun}{kw_parseempty}[function] with five arguments:
the @<set> name, as a string; the string pointer @<kwfirst>; the address of
a temporary argument-tail cursor object of type @|va_list|, constructed on
the assumption that @<kwfirst> is the enclosing function's final keyword
\end{describe}
\begin{describe}{mac}[KWPARSE_EMPTY]{KWPARSE_EMPTY(@<set>);}
- This is an analogue to \descref{KWPARSE}{mac} which checks that the
+ This is an analogue to \descref{mac}{KWPARSE} which checks that the
enclosing function has been passed no keyword arguments other than the
special predefined ones. It assumes that the first keyword name is in an
- argument named @|kwfirst_|, as set up by the \descref{KWTAIL}[marker]{mac}.
+ argument named @|kwfirst_|, as set up by the \descref{mac}{KWTAIL}[marker].
\end{describe}
\begin{describe}{fun}[kw_parseempty]
\xref{sec:runtime.keywords.calling}).
The @<set> argument should point to a null-terminated string: this will be
- reported as the keyword set name to \descref{kw_unknown}{fun}, though it
+ reported as the keyword set name to \descref{fun}{kw_unknown}, though it
need not (and likely will not) refer to any defined keyword set. The
remaining arguments are as for the keyword parsing functions defined by the
- \descref{KWSET_PARSEFN}[macro]{mac}.
+ \descref{mac}{KWSET_PARSEFN}[macro].
\end{describe}
\subsection{Function wrappers} \label{sec:runtime.keywords.wrappers}
in this case is meaningless.
In this situation, the parser functions generated by
-\descref{KWSET_PARSEFN}{mac} (and the \descref{kw_parseempty}[function]{fun})
+\descref{mac}{KWSET_PARSEFN} (and the \descref{fun}{kw_parseempty}[function])
call @|kw_unknown|.
\begin{describe}{fun}[kw_unknown]
keyword set expected by the caller, as a null-terminated string; and @<kw>
is the unknown keyword which was encountered. All that @|kw_unknown| does
is invoke the function whose address is stored in the global variable
- \descref{kw_unkhook}{var} with the same arguments.
+ \descref{var}{kw_unkhook} with the same arguments.
This function never returns to its caller: if the @|kw_unkhook| function
returns (which it shouldn't) then @|kw_unknown| writes a fatal error
need different arrangements. The author is willing to coordinate any
such efforts.} %
holds the current unknown-keyword handler function. It will be invoked by
- \descref{kw_unknown}{fun}. The function may take whatever action seems
+ \descref{fun}{kw_unknown}. The function may take whatever action seems
appropriate, but should not return to its caller.
Initially, this variable points to the
- \descref{kw_defunknown}[function]{fun}.
+ \descref{fun}{kw_defunknown}[function].
\end{describe}
\begin{describe}{fun}[kw_defunknown]
the keyword named by @<kw> is not known in the keyword set @<set>, and
calls \man{abort}{3}.
- This function is the default value of the \descref{kw_unkhook}[hook
- variable]{var}.
+ This function is the default value of the \descref{var}{kw_unkhook}[hook
+ variable].
\end{describe}
As an example of the kind of special effect which can be achieved using this
Keyword arguments for the initialization message may be provided. The
@|SOD_INIT| macro expects a single preprocessor-time argument which is
- a use of one of \descref*{KWARGS}{mac} or \descref{NO_KWARGS}{mac}; the
+ a use of one of \descref*{mac}{KWARGS} or \descref{mac}{NO_KWARGS}; the
@|sod_init| function expects the keywords as a variable-length argument
tail; and @|sod_initv| expects the keywords to be passed indirectly,
through the captured argument-tail cursor @<ap>.
Tears down an instance of a class, releasing any resources it holds.
This function is a very thin wrapper around sending the
- \descref*{obj.teardown}{msg} message. See the description of that message
+ \descref*{msg}{obj.teardown} message. See the description of that message
(\autopageref{msg:obj.teardown}) and \xref{sec:concepts.lifecycle.death}
for details.
\end{describe}
Keyword arguments for the initialization message may be provided. The
macro expects a single preprocessor-time argument which is a use of one of
- \descref*{KWARGS}{mac} or \descref{NO_KWARGS}{mac}.
+ \descref*{mac}{KWARGS} or \descref{mac}{NO_KWARGS}.
The instance has automatic storage duration: pointers to it will become
invalid when control exits the scope of the declaration. If necessary, the
instance should be torn down before this happens, using the
- \descref{sod_teardown}[function]{fun}.
+ \descref{fun}{sod_teardown}[function].
\end{describe}
\subsubsection{Dynamic allocation}
Keyword arguments for the initialization message may be provided. The
@|SOD_MAKE| macro expects a single preprocessor-time argument which is
- a use of one of \descref*{KWARGS}{mac} or \descref{NO_KWARGS}{mac}; the
+ a use of one of \descref*{mac}{KWARGS} or \descref{mac}{NO_KWARGS}; the
@|sod_make| function expects the keywords as a variable-length argument
tail; and @|sod_makev| expects the keywords to be passed indirectly,
through the captured argument-tail cursor @<ap>.
Storage for the new instance will have been allocated using the standard
@|malloc| function. The easiest way to destroy the instance, when it is no
longer needed, is probably to call the
- \descref{sod_destroy}[function]{fun}.
+ \descref{fun}{sod_destroy}[function].
The return value is an instance pointer for the class @<cls>; the
@|SOD_MAKE| macro will have converted it to the correct type, so it should
The pointer @<p> should be an instance pointer, i.e., a pointer to any of
an instance's chains. The instance is torn down, by sending it the
- \descref{obj.teardown}[message]{msg}. If the instance reports itself ready
+ \descref{msg}{obj.teardown}[message]. If the instance reports itself ready
for deallocation, then its storage is released using @|free|. The return
value is the value returned by the @|obj.teardown| message.
\end{describe}
}
\def\desc@end{\endlist\after@desc\global\let\after@desc\saved@after@desc}
+\def\@ifnextchar@preserve#1#2#3{%
+ \let\want@= #1\def\@tempa{#2}\def\@tempb{#3}%
+ \futurelet\nch@\@ifnch@p%
+}
+\def\@ifnch@p{%
+ \ifx\want@\nch@\expandafter\@tempa\else\expandafter\@tempb\fi}
+
\@namedef{describe*}#1{\desc@begin{#1}}
\expandafter\let\csname enddescribe*\endcsname\desc@end
\def\describe{\parse@dhd\desc@}
\def\descref{\@ifstar%
{\descref@i{}\@gobble{}}%
{\descref@i{ (}{\noexpand\autopageref}{)}}}
-\def\descref@i#1#2#3#4{\@ifnextchar[%
- {\descref@ii{#1}{#2}{#3}{#4}}%
- {\descref@iii{#1}{#2}{#3}{#4}{}}}
-\def\descref@ii#1#2#3#4[#5]{\descref@iii{#1}{#2}{#3}{#4}{ #5}}
+\def\descref@i#1#2#3#4#5{\@ifnextchar@preserve[%
+ {\descref@ii{#1}{#2}{#3}{#4}{#5}}%
+ {\descref@iii{#1}{#2}{#3}{#4}{#5}{}}}
+\def\descref@ii#1#2#3#4#5[#6]{\descref@iii{#1}{#2}{#3}{#4}{#5}{ #6}}
\def\descref@iii#1#2#3#4#5#6{%
\begingroup%
\let\protect\@empty%
\def\@uscore{-\@gobble}%
\edef\@tempa##1{%
\endgroup%
- \noexpand\hyperref[#6:#4]%
+ \noexpand\hyperref[#4:#5]%
##1%
- #2{#6:#4}%
+ #2{#4:#5}%
}%
- \@tempa{{\code{#4}}#5#1}#3%
+ \@tempa{{\code{#5}}#6#1}#3%
}
%%%----- That's all, folks --------------------------------------------------
Finally, an S-expression preceded by @|?| causes the expression to be read in
the current package (which is always @|sod-user| at the start of a module)
and immediately evaluated (using @|eval|); the resulting value is converted
-into a property value using the \descref{decode-property}[generic
-function]{gf}.
+into a property value using the \descref{gf}{decode-property}[generic
+function].
\subsection{Property output types and coercions}
When a property value is inspected by the Sod translator, or an extension, it
is \emph{coerced} so as to conform to a requested output type. This coercion
-process is performed by the \descref{coerce-property-value}[generic
-function]{gf}, and additional output types and coercions can be defined by
+process is performed by the \descref{gf}{coerce-property-value}[generic
+function], and additional output types and coercions can be defined by
extensions. The built-in output types coercions, from the value types listed
above, are as follows.
~mdw / sod / commitdiff