Attribute

Attribute specifications may appear in dataset, array, table and column body specifications. There is no limit to the number of specifications which may appear in each of the allowed specification bodies. Within each body section attribute names must be unique.

The general form of an attribute specification is given by

    attribute attribute-name attribute-data-type value label units optional-expression
    < 
        ... attribute item specifications ... 
    >

where,

• attribute is the attribute specification keyword. This keyword is used to begin a new attribute specification.

• attribute-name is the attribute name. There must be no other attributes in the attribute's parent with the same name. It has type string-expression (which may be a literal string).

• attribute-data-type is the attribute data type. The available types are int, real, bool, string.

• value is the attribute value. It is an expression (which may be a literal value) which must evaluate to a value whose type is consistent with attribute-data-type.

• label is a short description. It has type string-expression (which may be a literal string).

• units is the attribute's units. It has type string-expression (which may be a literal-string).

• optional-expression is an optional expression which is evaluated after the last item in the body has been evaluated.

In general, the body of an attribute will not be needed.