Contract based Programming

Question

Can someone explain the concepts that Spec# might be moving into C# 4.0, regarding Code Contracts?

• What are code contracts (Looks to be a compile time checking pattern)
• should I be excited about this?
• Am I correct in assuming that we move what would be runtime checks to compile time?

Thanks!

Answer 1

I personally am a big fan of a guy called Bertrand Meyer who wrote this book called Object Oriented Software Contruction and created a language called Eiffel which endoreses Design By Contract or Contract based programming.

1. Code Contract is a kind of agreement between 2 software entities that may or may not interact. More or less like interfaces but more precise.
2. I am not sure if everyone should or would be excited about this.
3. Your assumption is somewhat correct.

You might want to see this series of videos link

Answer 2

Here's a good description of code contracts straight from Microsoft Research. It sounds like the main benefits are:

• Improved testability
• Static verification
• API documentation (in code)