Type Conversions in BMCS

BMCS now has the basic infrastructure in place to do VB.NET like Type Conversions - both Implicit and Explicit.

The changes turned out to be much simpler than I had earlier thought.

The main difficulty was the nomenclature used by the C# and VB.NET specifications. It took sometime for me to realize the following two facts:

1. VB.NET 's notion of "Widening and Narrowing Conversions" is equivalent to C# 's notion of "Implicit and Explicit Conversions".
2. VB.NET has no notion of "User Defined Conversions".

Once the above essential facts were in place, a quick renaming of gmcs's conversion methods and a little bit of refactoring put everything in perspective. (Whoever asked "What is in a name?" should definitely be a fool!)

One biggest challenge introduced by the above renaming and considerable deletions (VB.NET has no unsigned data type other than "Byte", you see) is the increased lexical distance between the gmcs and bmcs trees.

I was immediately tempted to assess how much of a overhead that it introduces in merging of the two trees. After my second merge, I would say that it makes my life more difficult. Eventhough merging in itself is more of a pain, verifying that it indeed is just fine is actually much easier - just do a "diff of diffs" and verify that the only diffs are in the "positions of the diff".

Once I am done with giving final touches to the conversion changes, I think I might resort to "re renaming" the methods. (Whoever asked "What's in a name?" definitely has his feet firmly on the ground!)

My next goal is to VBify expression semantics and follow that up with a "rigorous" article on how C# and VB.NET differ with respect to Type Conversions.