:Using Statement

:Using <NameSpace[,Assembly]>

This statement specifies a .NET namespace that is to be searched to resolve unqualified names of .NET types referenced by expressions in the Class.

Element	Description
NameSpace	Specifies a .NET namespace.
Assembly	Specifies the Assembly in which NameSpace is located. If the Assembly is located in the Microsoft.NET installation directory, you need only specify its name. If not, you must specify a full or relative pathname.

If the Microsoft .NET Framework is installed, the System namespace inmscorlib.dll is automatically loaded when Dyalog APL starts. To access this namespace, it is not necessary to specify the name of the Assembly.

When the class is fixed, ⎕USING is inherited from the surrounding space. Each :Using statement appends an element to ⎕USING, with the exception of :Using with no argument:

If you omit <Namespace>, this is equivalent to clearing ⎕USING, which means that no .NET namespaces will be searched (unless you follow this statement with additional :Using statements, each of which will append to ⎕USING).

To set ⎕USING, to a single empty character vector, which only allows references to fully qualified names of classes in mscorlib.dll, you must write:

:Using , (note the presence of the comma)

or

:Using ,mscorlib.dll

that is, specify an empty namespace name followed by no assembly, or followed by the default assembly, which is always loaded.