+ * Address ranges (addrmap.c):
+ *
+ * An address range is a slightly efficient partial mapping from
+ * addresses to arbitrary data values. An address is a number of
+ * octets expressed as an hbytes. All the addresses covered by the
+ * same addrmap should have the same length.
+ *
+ * hbytes addr-map lookup MAP-VAR ADDRESS [DEFAULT] => DATA
+ * Error on missing default or if any prefix longer than ADDRESS.
+ *
+ * hbytes addr-map amend-range MAP-VAR START END DATA
+ * hbytes addr-map amend-mask MAP-VAR PREFIX PREFIX-LENGTH DATA
+ * Sets all of the addresses in PREFIX/PREFIX-LENGTH to the
+ * relevant value.
+ *
+ * Representation:
+ * An address map MAP is
+ * [list BIT-LENGTH \
+ * [list START END DATA-VALUE] \
+ * [list START' END' DATA-VALUE'] \
+ * ...
+ * ]
+ * The list is sorted by ascending START and entries do not overlap.
+ * START and END are both inclusive. BIT-LENGTH is in usual Tcl
+ * integer notation and must be a multiple of 8.
+ *