Extended References

An extended reference is a reference to an entity that is located in another namespace. The namespace name can be specified as a string literal enclosed in quotes, as a variable that resolves to a namespace name, as an implied namespace name, or as a null string ("") a placeholder that specifies the current namespace. There are three types of extended references:

Extended Global Reference: references a global variable in another namespace. The following syntactic forms are supported: ^["namespace"]global and ^|"namespace"|global. For further details, see Global Variables.
Extended Routine Reference: references a routine in another namespace.
- The DO command, the $TEXT function, and user-defined functions support the following syntactic form: |"namespace"|routine.
- The JOB command supports the following syntactic forms: routine|"namespace"|, routine["namespace"], or routine:"namespace".
In all these cases, the extended routine reference is prefaced by a ^ (caret) character to indicate that the specified entity is a routine (rather than a label or an offset). This caret is not part of the routine name. For example, DO ^|"SAMPLES"|fibonacci invokes the routine named fibonacci, which is located in the SAMPLES namespace. The command WRITE $$fun^|"SAMPLES"|house invokes the user-defined function fun() in the routine house, located in the SAMPLES namespace.
Extended SSVN Reference: references a structured system variable (SSVN) in another namespace. The following syntactic forms are supported: ^$["namespace"]ssvn and ^$|"namespace"|ssvn. For further details, refer to the ^$GLOBAL, ^$LOCK, and ^$ROUTINE structured system variables.

All extended references can, of course, specify the current namespace, either explicitly by name, or by specifying a null string placeholder.