Search Function; Restrictions On Indexing, Subscripting And Qualification - Control Data Corporation 3300 Reference Manual

4.5.3
SEARCH FUNCTION
4.5.4
RESTRICTIONS ON
INDEXING,
SUBSCRIPTING
AND QUALIFICATION
4-16
Composite format:
data-name [
1
~t
data-name-l }indeX-name
[l:
~
integer]
[ , index -name
[l
~
t
integer]
J.. . )
The search function operates in the linear mode (SEARCH) or the binary
bisecting mode (SEARCH ALL). Both types of search terminate when a
stated condition is met when table element equals search argument. All
tables to be searched must have at least one element described as an index
name with the INDEXED BY option of the OCCURS clause. The index name
is incremented during search operations by the element character offset,
and the index name always contains the character address bias of the table
entry currently being compared. See paragraph 4.3.4 for rules governing
the comparison of index names and index data items.
The element character offset is the number of character positions in a table
element. The character address bias is the value added to the base character
address of the table to give the character address of a particular element
in the table.
Tables may have one, two, or three dimensions; therefore, references to an
element in a table may require up to three subscripts or indexes.
A data name may not be subscripted nor indexed when the data name is used
as an index, subscript, or qualifier.
When a data item requires qualification, subscripting or indexing, the indexes
or subscripts are stated following all necessary qualification.
Subscripting and indexing must not be used together in a single reference.
Where subscripting is not permitted, indexing is also not permitted.
An index can be modified only by the SET, SEARCH, and PERFORM statements.
Index data items are described by USAGE IS INDEX. They permit storage of
the values of index names as data with conversion.
The commas shown in the formats for indexes and subscripts are required.
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