Language design for Refactoring
A question came up on the Yahoo! Groups Refactoring Group about what language design would be best to support Refactoring.
We think about this quite a bit, but usually we phrase the question more generally:
What language design would make it easiest to write tools that work well?
That includes Refactoring, as well as Intellisense, Syntax Coloring, etc.
The answer seems to be that explicitness: a language that forces the developer to be explicit, instead of implicitly inferring stuff from the context.
It seems like this is really the answer to:
What language design makes the code easy to read?
Unfortunately, language readability is often at odds with writability. This is a point that language designers struggle with all the time.
In C# 2.0, there are two points of inference that were added to the language:
- Generic method type parameters are inferred from the concrete parameters.
- Anonymous method type is inferred from the usage
We discussed, but did not add inference of the type of the instance variable in a ‘foreach’ statement.
There’s an MSDN Magazine article that discusses some of these points in C# 2.0.
In general, the design of C# has focused on making your code more explicit that C++, to avoid many of the pitfalls we observed in C++. That same explicitness has made C# Refactoring easier to get right.
