Add Cobra support for namespace aliasing/Masking

[hopscc]

C# allows dismabiguation of colliding namespaces or aliasing a complex namespace name to something simpler with syntax on its using statement
Cobra should provide a similar capability for similar purposes
e.g.
Namespace with own version of type Console ambiguous with System.Console.

using Console = Wrapper.Console;

See  Discussion Topic

[hopscc]

Patch for both namespace and class in Namespaces aliasing.
Cleanup duplicated code in bindUsePhase
Additional tests.

[Charles]

bump

[Charles]

rebump

[Charles]

This ticket mentions the C# syntax of:

using NewName = Existing.Name.Space;

The patch syntax is:

use Existing.Name.Space as NewName

Right now "as" is used for typing as in "x as List<of String>" or "i as int".

And "=" is used for assignment of values such as "i = 5".

All things considered, I think the "=" syntax is more appropriate than "as" because we are "assigning a name" rather than "declaring a type". Example:

use System.Web
use MyCompany.MyProject.Common
use Media = SomeProject.Foo.Media

[hopscc]

re 'as'
1) used for typing only in a variable dcl - 'use' isnt a variable dcl
2) We are declaring an alias for a namespace (name) - the namespace can be construed as a type (envelope)
and (more importantly)
'as' reads/parses clearer than 'equals' when reading it
(i.e. what its doing rather than what it (may) resemble)

use Nspace.X as nameY
#vs
use Nspace.X equals nameY

to be congruent with an assignment you'd want to reverse the order

use nameY equals Nspace.X
use nameY = Nspace.X

But its not an assignment and the alias name isn't a variable

(in the patch CobraParser line 507 'AS' -> 'EQUALS')

[Charles]

On the way.

[Charles]

Thanks.

I went with the original assignment based syntax.

changeset:3114