Language Reference/Namespaces

Namespaces can be used to avoid name clashes, without having to use long strange names. The names in two different namespaces will never clash, but it may be necessary to qualify references with the namespace (or part of it) to resolve ambiguities.

A namespaces are declared and defined implicitly using NamespaceEntrance'es:

NamespaceEntrance:
   namespace NamespaceIdentifier

NamespaceIdentifier: one of
   LowercaseIdentifier
   LowercaseIdentifier \ NamespaceIdentifier

In short a NamespaceIdentifier is a sequence of lowercase identifiers separated by backslashes.

Namespace Entrances and Regions

Namespace entrances divide source files into namespace regions.

A namespace entrance marks the beginning of a namespace region, which ends ends at the next namespace entrance or the end of the file.

Every file starts in the root namespace.

Namespace regions are not influenced by #include directives, meaning:

• Namespace entrances in an #include-file does not change the namespace region in the including file
• Any file starts in the root namespace (also if it is included inside a namespace region in another file).

Any interface, class and implementation that is meet inside a namespace region belongs to that namespace.

Example

class aaa
end class aaa
 
namespace xxx
 
class bbb
end class bbb
 
namespace xxx\yyy
 
class ccc
end class ccc

This file is divided in three regions (assuming that it is a complete file). The first region is in the root namespace (\), the second region belongs to the xxx namespace and the third region belongs to the xxx\yyy namespace.

Subsequently, the class aaa belongs to the root namespace, the class bbb belongs to the namespace xxx and finally the class ccc belongs to the namespace xxx\yyy.

Referencing names in namespaces

If ccc is a class in the namespace xxx\yyy, then the full name of ccc is \xxx\yyy\ccc.

The leading backslash indicates that we start from the root namespace.

A class/interface can always be uniqly referenced using its full name.

The full names are not always convenient and therefore it is possible to use shorter names in certain situations.

Open namespaces

First of all it is possible to open namespaces inside a scope:

class aaa
    open xxx\yyy\
...
end class aaa

Opening a namespace is distinguished from opening a class/interface by the trailing backslash.

The namespace that a certain scope (i.e. interface/class/implementation) belongs to is (implicitly) open inside that scope.

Namespace qualification

Since several namespaces be open simultaneously it is possible that names may clash. Using the full name it is always possible to resolve any ambiguity.

But it is also possible to use suffix qualification. With suffix qualification you write a suffix of the namespace. A suffix goes from right after a backslash to the end of the namespace identifier.

Example The suffixes of \xxx\yyy\zzz are:

xxx\yyy\zzz
yyy\zzz
zzz

So if aaa is a class in \xxx\yyy\zzz, these are the possible suffix qualifications:

xxx\yyy\zzz::aaa
yyy\zzz::aaa
zzz::aaa