Scopes designate :term:`channel` instances on the unified bus. :term:`Channel` instances are themselves hierarchical, hence scopes also reflect this structure.
There is a string-based notation for scopes based on UNIX/URL paths. For example:
/a/b/c/
This scope designates the :term:`channel` /a/b/c/
which is a
sub-:term:`channel` of the :term:`channels <channel>` designated by:
/a/b/ /a/ /
/
is sometimes called "root-scope".
Generally, a scope string is valid if it matches the regular expression :regexp:`/([-_a-zA-Z0-9]+/)*`, i.e. scopes are case-sensitive.
Note
For convenience, the final /
in scope strings may be omitted
when specifying scopes in user interfaces. However, when scope
strings are used as keys in associative arrays or in network
protocols, scope strings have to be normalized such that they
contain the terminating /
.
The scope /__rsb/
and its :term:`subscopes <subscope>` are
reserved for implementation purposes and should not be used for
user-level communication.
When designing communication patterns based on |project|, it is sometimes necessary to derive components of :term:`scopes <scope>` from arbitrary strings. This section defines a procedure that should be used when such a derivation is needed:
- Replace any character of the input string that is not one of the
allowed :term:`scope` component characters (i.e.
[-_a-zA-Z0-9]
) with the_
character. - The resulting string can be used as a component in a :term:`scope`.
Note
Of course, this procedure does not necessarily produce distinct :term:`scope` components from distinct strings. This possibility of clashes has to be taken into account.
Language | File(s) |
---|---|
C++ | |repository_versioned_cpp| at src/rsb/Scope.{h,cpp} |
Java | :download:`upstream/rsb-java/rsb-java/src/main/java/rsb/Scope.java` |
Python | :download:`upstream/rsb-python/rsb/__init__.py` |
Common Lisp | :download:`upstream/rsb-cl/src/scope.lisp` |