The declarations in an interface definition body are one or more of the following:
import_declaration
constant_declaration
type_declaration
operation_declaration
A ; (semicolon) terminates each declaration, and { } (braces) enclose the entire body.
Import declarations must precede other declarations in the interface body. Import declarations specify the names of other IDL interfaces that define types and constants used by the importing interface.
Constant, type, and operation declarations specify the constants, types, and operations that the interface exports. These declarations can be coded in any order, provided any constant or type is defined before it is used.