-typedef int (*mandocmsg)(enum mandocerr,
- void *, int, int, const char *);
+/*
+ * Available registers (set in libroff, accessed elsewhere).
+ */
+enum regs {
+ REG_nS = 0,
+ REG__MAX
+};
+
+/*
+ * A register (struct reg) can consist of many types: this consists of
+ * normalised types from the original string form.
+ */
+union regval {
+ unsigned u; /* unsigned integer */
+};
+
+/*
+ * A single register entity. If "set" is zero, the value of the
+ * register should be the default one, which is per-register. It's
+ * assumed that callers know which type in "v" corresponds to which
+ * register value.
+ */
+struct reg {
+ int set; /* whether set or not */
+ union regval v; /* parsed data */
+};
+
+/*
+ * The primary interface to setting register values is in libroff,
+ * although libmdoc and libman from time to time will manipulate
+ * registers (such as `.Sh SYNOPSIS' enabling REG_nS).
+ */
+struct regset {
+ struct reg regs[REG__MAX];
+};
+
+__BEGIN_DECLS
+
+/*
+ * Callback function for warnings, errors, and fatal errors as they
+ * occur in the compilers libroff, libmdoc, and libman.
+ */
+typedef int (*mandocmsg)(enum mandocerr, void *,
+ int, int, const char *);