Download Technica.

TYPESETTING AN INDEX
119
the index entry, you should of course modify the \Facies attribute of the
\textus subclass for the entry [ carmina ][ fleurs ].
In most cases, you will also need to change the \Facies attribute for the
\numerus subclasses themselves; in defining \Facies you should always
make an explicit test for the value 0 (making sure no text is typeset for
it): τεχνικˆ sets the value to 0 whenever it would not be appropriate to
print the original value [ carmina ][ fleurs ].
Setting the layout of the index
An index is not usually typeset as a continuous, uninterrupted sequence of
lines. A group of entries sharing the same initial letter is separated from the
previous group by some blank space and often the initial letter of the first
line of the group is typeset in a larger font. Sometimes the common initial
letter is typeset on a separate line, as a sort of title. All these styles are
easily obtained with τεχνικˆ.
Whenever the initial letter of an entry differs from that of the previous entry,
the software automatically issues the command \IndexSeparator with the
new initial as the argument. \IndexSeparator is a predefined (locally within
the index) \titulus subclass created with these attributes:
\Facies \IndexSeparator {}
\SpatiumSupra
{.5\leading}
Because \Facies is empty[ 34 ], the command argument (the initial letter)
is ignored but \SpatiumSupra is obeyed, inserting blank space before the
new group of entries. By redefining the attributes (and perhaps adding
\SpatiumInfra) you can have the letter in the argument typeset above
the group.
The initial letter of the first entry of a group is treated by τεχνικˆ as an
incipit (just like the beginning of the first line of a poem [ 43 ]) and is typeset
according to \Facies \incipit. Within the index, \Facies \incipit is
empty, so that the letter is typeset without alteration. By redefining the
attribute, you can specify how the letter should be typeset; the attribute
definition must not contain references to parameters other than #1 (only
the first letter should be affected).