Simon Willison’s Weblog

Strong Typing vs Strong Testing

In Strong Typing vs. Strong Testing, Bruce Eckel reconsiders the old idea that languages without strong typing can’t be relied on to create large programs:

This became a puzzle to me: if strong static type checking is so important, why are people able to build big, complex Python programs (with much shorter time and effort than the strong static counterparts) without the disaster that I was so sure would ensue?

His conclusion is that type checking by the compiler does not garauntee the correctness of a program in the first place; it’s just another test. Comprehensive unit testing can more than compensate for the lack of type checking in languages such as Python, especially since the huge productivity bonus provided by Python allows more tests to be written starting at an earlier stage in development.

Incidentally, Bruce recently added an RSS feed.