How do we ensure that method type inference terminates?

Here’s a question I got from a coworker recently:

It is obviously important that the C# compiler not go into infinite loops. How do we ensure that the method type inference algorithm terminates?

The answer is quite straightforward actually, but if you are not familiar with method type inference then this article is going to make no sense. You might want to watch this video if you need a refresher. Continue reading

Foolish consistency is foolish

Once again today’s posting is presented as a dialogue, as is my wont.

Why is var sometimes required on an implicitly-typed local variable and sometimes illegal on an implicitly typed local variable?

That’s a good question but can you make it more precise? Start by listing the situations in which an implicitly-typed local variable either must or must not use var.

Sure. An implicitly-typed local variable must be declared with var in the following statements:

Continue reading

A face made for email, part three

It has happened again: someone has put me on video talking about programming languages.

This time our fabulous C# Community Program Manager Charlie Calvert was good enough to put together a little half-hour-long video of me talking about the scenarios which justify changes to the type inference algorithm for C# 3.0.

The video is here. Enjoy!