Note: information on this page refers to Ceylon 1.0, not to the current release.


Keywords are reserved tokens whose role in the language is defined in the language specification. They may not be used as identifiers.


Usage depends on the keyword in question.


The following are reserved keywords:


It is possible to quote keywords, creating an identifier from a character sequence which would otherwise be treated as keyword by the lexer. For example \iout creates an identifier called out. The intended purpose of quoting is interoperation with other languages. For example, it may be necessary to invoke or refine a method named out on a class written in Java (where out is not a keyword).


Other identifiers commonly seen in declarations (such as shared) are not keywords but annotations.

See also