-\begin{prog}
- struct SodClass__vt_obj \{ \\ \ind
- const SodClass *_class; \\
- size_t _base; \- \\
- \};
- \\[\bigskipamount]
- struct SodObject__ilayout \{ \\ \ind
- union \{ \\ \ind
- struct SodClass__ichain_obj \{ \\ \ind
- const struct SodClass__vt_obj *_vt; \\
- struct SodClass__islots \{ \\ \ind
- const char *name; \\
- const char *nick; \\
- size_t initsz; \\
- void *(*imprint)(void *@<p>); \\
- void *(*init)(void *@<p>); \\
- size_t n_supers; \\
- const SodClass *const *supers; \\
- size_t n_cpl; \\
- const SodClass *const *cpl; \\
- const SodClass *link; \\
- const SodClass *head; \\
- size_t level; \\
- size_t n_chains; \\
- const struct sod_chain *chains; \\
- size_t off_islots; \\
- size_t islotsz; \- \\
- \} cls; \- \\
- \}; \\
- SodObject obj; \- \\
- \} obj; \- \\
- \};
-\end{prog}
-
-The @|SodClass| class defines no messages, but there are a number of slots.
-Its only direct superclass is @|SodObject| and so (like its superclass) its
-vtable is trivial.
-
-The slots defined are as follows.
-\begin{description} \let\makelabel\code
-
-\item[const char *name] A pointer to the class's name.
-
-\item[const char *nick] A pointer to the class's nickname.
-
-\item[size_t initsz] The size in bytes required to store an instance of the
- class.
-
-\item[void *(*imprint)(void *@<p>)] A pointer to a function: given a pointer
- @<p> to at least @<initsz> bytes of appropriately aligned memory, `imprint'
- this memory it so that it becomes a minimally functional instance of the
- class: all of the vtable and class pointers are properly initialized, but
- the slots are left untouched. The function returns its argument @<p>.
-
-\item[void *(*init)(void *@<p>)] A pointer to a function: given a pointer
- @<p> to at least @<initsz> bytes of appropriately aligned memory,
- initialize an instance of the class in it: all of the vtable and class
- pointers are initialized, as are slots for which initializers are defined.
- Other slots are left untouched. The function returns its argument @<p>.
+\begin{describe}[SodClass]{cls}
+ {[nick = cls, link = SodObject] \\
+ class SodClass : SodObject \{ \\ \ind
+ const char *name; \\
+ const char *nick; \\
+ size_t initsz; \\
+ void *(*imprint)(void *@<p>); \\
+ void *(*init)(void *@<p>); \\
+ size_t n_supers; \\
+ const SodClass *const *supers; \\
+ size_t n_cpl; \\
+ const SodClass *const *cpl; \\
+ const SodClass *link; \\
+ const SodClass *head; \\
+ size_t level; \\
+ size_t n_chains; \\
+ const struct sod_chain *chains; \\
+ size_t off_islots; \\
+ size_t islotsz; \- \\
+ \}}
+
+ The @|SodClass| class defines no messages, but there are a number of slots.
+ Its only direct superclass is @|SodObject| and so (like its superclass) its
+ vtable is trivial.
+
+ The slots defined are as follows.
+ \begin{description} \let\makelabel\code
+
+ \item[name] A pointer to the class's name.
+
+ \item[nick] A pointer to the class's nickname.
+
+ \item[initsz] The size in bytes required to store an instance of the class.
+
+ \item[imprint] A pointer to a function: given a pointer @<p> to at least
+ @<initsz> bytes of appropriately aligned memory, `imprint' this memory it
+ so that it becomes a minimally functional instance of the class: all of
+ the vtable and class pointers are properly initialized, but the slots are
+ left untouched. The function returns its argument @<p>.
+
+ \item[init] A pointer to a function: given a pointer @<p> to at least
+ @<initsz> bytes of appropriately aligned memory, initialize an instance
+ of the class in it: all of the vtable and class pointers are initialized,
+ as are slots for which initializers are defined. Other slots are left
+ untouched. The function returns its argument @<p>.
+
+ \item[n_supers] The number of direct superclasses. (This is zero exactly
+ in the case of @|SodObject|.)
+
+ \item[supers] A pointer to an array of @<n_supers> pointers to class
+ objects listing the class's direct superclasses, in the order in which
+ they were listed in the class definition. If @<n_supers> is zero, then
+ this pointer is null.
+
+ \item[n_cpl] The number of superclasses in the class's class precedence
+ list.
+
+ \item[cpl] A pointer to an array of pointers to class objects listing all
+ of the class's superclasses, from most- to least-specific, starting with
+ the class itself, so $@|$c$@->cls.cpl[0]| = c$ for all class objects
+ $c$.
+
+ \item[link] If the class is a chain head, then this is a null pointer;
+ otherwise it points to the class's distinguished link superclass (which
+ might or might not be a direct superclass).
+
+ \item[head] A pointer to the least-specific class in this class's chain; so
+ @|$c$@->cls.head@->cls.link| is always null, and either @|$c$@->cls.link|
+ is null (in which case $@|$c$@->cls.head| = c$) or $@|$c$@->cls.head| =
+ @|$c$@->cls.link@->cls.head|$.
+
+ \item[level] The number of less specific superclasses in this class's
+ chain. If @|$c$@->cls.link| is null then @|$c$@->cls.level| is zero;
+ otherwise $@|$c$@->cls.level| = @|$c$@->cls.link@->cls.level| + 1$.
+
+ \item[n_chains] The number of chains formed by the class's superclasses.
+
+ \item[chains] A pointer to an array of @|struct sod_chain| structures (see
+ below) describing the class's superclass chains, in decreasing order of
+ specificity of their most specific classes. It is always the case that
+ $@|$c$@->cls.chains[0].classes[$c$@->cls.level]| = c$.
+
+ \item[off_islots] The offset of the class's @|islots| structure relative to
+ its containing @|ichain| structure. The class doesn't define any slots
+ if and only if this is zero. (The offset can't be zero because the
+ vtable pointer is at offset zero.)
+
+ \item[islotsz] The size required to store the class's direct slots, i.e.,
+ the size of its @|islots| structure. The class doesn't define any slots
+ if and only if this is zero.
+
+ \end{description}
+\end{describe}
+
+\begin{describe}[struct sod_chain]{type}
+ {struct sod_chain \{ \\ \ind
+ size_t n_classes; \\
+ const SodClass *const *classes; \\
+ size_t off_ichain; \\
+ const struct sod_vtable *vt; \\
+ size_t ichainsz; \- \\
+ \};}
+
+ The @|struct sod_chain| structure describes an individual chain of
+ superclasses. It has the following members.
+ \begin{description} \let\makelabel\code
+
+ \item[n_classes] The number of classes in the chain. This is always at
+ least one.
+
+ \item[classes] A pointer to an array of class pointers listing the classes
+ in the chain from least- to most-specific. So
+ $@|@<classes>[$i$]@->cls.head| = @|@<classes>[0]|$ for all $0 \le i <
+ @<n_classes>$, @|@<classes>[0]@->cls.link| is always null, and
+ $@|@<classes>[$i$]@->cls.link| = @|@<classes>[$i - 1$]|$ if $1 \le i <
+ @<n_classes>$.
~mdw / sod / blobdiff