Java Enterprise in a Nutshell, Third Edition

Identifiers

Identifiers can name various IDL constructs, such as modules, interfaces, and constants. In IDL, an identifier has to follow these rules:

• It can be any length of alphanumeric characters from the ISO Latin-1^[75] character set (e.g., a-z, A-Z, 0-9, plus various characters with accents, graves, tildes, etc.), and the underscore character ( _ ).

• All characters in an identifier are significant.

• The first character must be an alphabetic character.

• Identifiers are case-insensitive, in the sense that two identifiers that differ only by case are considered a name collision and will cause an IDL compiler error. This rule stems from the fact that IDL needs to be mappable into many implementation languages, some of which are case-insensitive.

• Identifiers must be spelled and capitalized consistently throughout an IDL file.

• All IDL identifiers share the same namespace, so interfaces, modules, user-defined types, and so on within the same scope all must have unique identifiers. An interface named List and a module named List within the same scope will cause a name collision and an IDL compiler error. See "Naming Scopes" later in this appendix for more details.

Mapping Identifiers to Java

An IDL-to-Java compiler attempts to map all IDL identifiers unchanged into equivalent Java identifiers.

An exception is the case in which a mapped identifier conflicts with an identifier created automatically by the IDL compiler. IDL interfaces, for example, when they are mapped to Java, have two additional ...