The Thot editor provides a tool [Richy92] that allows index tables to be created and used, such as the one shown in Figure 8. These indexes are composed of alphabetical tables in which the significant terms of a document are mentioned. These indexes also contain links which allow you to move throughout the document as a hypertext, from these tables, regardless of the logical structure of the document.
More precise than the printed indexes which only refer to pages of a document, these indexes allow you to find within the document the part, the sentence or the section dealing with the required term. These indexes can be used while editing, not only when reading documents.
L
Le Breton, Auguste: 112
Li, chemical symbol of lithium: 73
Li, Chinese measure: see Measures
Literature, evolution of: 107, 119-123, see also Theater African: 12, 102, 125 American: 34, 104 European: 106-108
Figure 8 - Extract from an index table
The following steps are required to create index tables:
The following sections describe these various operations in further detail.
If the document does not already contain index marks, this command loads the extension needed by the indexing tool into the editor. You can then insert Index_marks within the document with the usual ``Insert'' command of the editor as described in section 22.4. Moreover, the views associated with the indexing tool (see section 22.2) are automatically added to the views defined for this type of document.
If the document already contains Index_marks, the extensions needed by indexes are loaded at the same time as the document (when it is opened).
To display indexes, several views are defined in the presentation schema of indexes. The following views are added by the indexing tool and can be opened and closed at any time, like any other view (see section 9.1):
The Index_tables view can be used in the same way as the table of contents view. The Index_tables view allows you to access the document through its contents: just double-click on a reference (page number or section number) or on a cross-reference. The contents of index tables cannot be directly edited with the Iindex_tables view, because it is constructed from the information contained in descriptors (see section 22.6).
By clicking on the index marks in the main view of the document, the corresponding descriptor is displayed and selected in the Descriptors view where it can be edited. The Descriptors, Cross_descriptors and Options views are of interest only to the author of the document when he or she builds index tables.
Thot only builds index tables if the required parameters have been previously defined. These parameters are described in document elements, the Options, which are displayed in a view separated from the document, the ``Options'' view.
If there are several index tables defined for the same document, each of them is subject to a specific description by an Option element, thus permitting the definition of the structure, the presentation and the contents of each table independently. To obtain the description of an index table, use the ``Insert'' command once you have selected an Option element in the Options view.
The description of an index table is created by editing the four fields of the corresponding Option element:
Other parameters are determined by attributes applied to the Index_title. To modify one of these attributes, select the Index_title and choose the attribute to be changed in the ``Attributes'' menu:
An Idx_Subject can have a Pres_subject attribute which defines the style of a given subject: roman, bold, italic, italic and bold (ItalBold). Roman is the default style.
The table title and the introduction are included in the index table: they are live copies of text. As a result, any change in such elements in Options produces an immediate result on the corresponding index table. On the opposite, any change in other options, any addition or removal of a new list of options will not have an immediate action on the contents of index tables. To see the result of this, issue the ``Make index tables'' command (see section 22.6).
A document is indexed by applying index marks throughout the text and filling the corresponding descriptors to enable the indexing tool to create index tables.
Once this part has been selected, apply an Index_mark pair around by calling the ``Insert'' menu and by choosing the entry ``Index_mark around'' [10]. Mark pairs which delimit different areas can be placed inside each other or can overlap. The command allows you to delimit the selected part with a pair of Index_marks and to create the corresponding descriptor that you must then fill.
Index_marks can be shown or hidden, depending on the visibility threshold (see section 10.2) of the main view. Marks disappear if the visibility threshold is equal or less than 5; a higher threshold make them appear. They always appear when you create a new mark pair; they are never printed.
By double-clicking on one of the two marks of a pair, you select the corresponding Descriptor and open the Descriptors view if it is not already opened.
A Value attribute is associated with the Keys element. It allows the user to specify the importance of the entry described by a specific presentation applied to the reference (the page number or the section number). This attribute can have three possible values (see section 6.2 to change the value of an attribute):
The Subject field is not controlled. As a consequence, it is recommended that you avoid typing errors and that you make a judicious choice for subject names in order to create the required tables. Moreover, a descriptor can have only one subject. If you want to create a single index table, do not specify the subject of descriptors.
In the index table, the comment is an inclusion (see section 4.6) of the Gloss of a descriptor. Thus, any update of this Gloss in a descriptor immediately appears in the comments of the corresponding index tables. On the opposite, any change in other fields of a descriptor or any addition or removal (when applying or removing marks) will not immediately change on the contents of index tables: you have to invoke the ``Make index tables'' command from the ``Tools'' menu (see section 22.6) to update index tables.
A Descriptor is always attached to the marks which have created it: it can be removed only by using a command for removing marks. You cannot directly create a Descriptor. All editing commands applied to marks also apply to the associated Descriptor (copy, cut, paste).
You can double-click on a Descriptor to select the corresponding mark pair.
When a mark pair, and so its Descriptor, are deleted, the descriptor of a Reference (see 22.5) to the deleted Descriptor is not deleted but it will appear with a symbol specifying an empty reference (for instance [?]). These changes are displayed once you have rebuilt the index tables (see the ``Make index tables'' described in 22.6).
Index marks can be displayed or hidden, depending on the visibility threshold (see section 10.2) of the main view. Marks disappear when the visibility threshold is less than or equal to 5; they appear with a higher threshold. They always appear when a new mark pair is created; they are never printed.
In an index table, cross-references are references which do not indicate a page number but the text of another entry (simple or with several levels), as ``see Measures'' or ``see also Theater'' in the example of Figure 8.
The cross-references defined in a document are not precisely located within the document. They are not associated with a mark pair.
Descriptors of cross-references, in the same way as Descriptors of marks, determine what will be displayed in the index. The fields of these descriptors are similar to those of the descriptors associated with marks. An additional field, Referring, establishes a link with a mark Descriptor.
No special interface is required to handle descriptors of Cross-references: just ask the editor to open the Cross-descriptors view. They can be added, modified or deleted like the other elements of the document.
A reference to an existing Descriptor is ignored if it has a Subject not consistent with the table being created: only internal references to a table are created in an index table.
When a mark Descriptor (being referenced) is deleted, the descriptor of the Cross-reference to the deleted descriptor is displayed with a symbol specifying an empty reference (a [?] is displayed at the position of the reference).
The command ``Make index tables'' from the ``Tools'' menu allows you to build the index tables of a document from the information contained in index marks, descriptors and options. It can only be applied to documents previously opened and containing index marks. If the document does not contain index marks, this command just loads the information required by the indexing tool (see section 22.1).
When you click on the ``Make index tables'' command, the message ``INDEX: index not defined in this document'' is displayed in the Thot window if no building option for indexes has been defined in the Options view (see section 22.3 to define the presentation options of tables). In this case, no operation is performed by the indexing tool even if the document contains index marks.
If the document contains the definition of options (in the Options view), the ``Make index tables'' command displays the form ``Index to build'':
Index tables can be modified only with the ``Make index tables'' command. To ensure that marks, descriptors, options and tables are consistent, no editing operation are allowed on an index table or any element.