In my experience, no matter how sophisticated a static type system is, at some point it ends up getting in my way. This goes double for languages with very simplistic type systems, such as C#, as they have all of the disadvantages of a static type system with few of its advantages.
Statically typed languages tend to lack good REPLs, a tool I consider indispensable. I'm unaware of any statically typed language that has something as complete and integrated as SLIME, for instance. Even a properly setup IRB or IPython don't seem to have anything that matches them in the statically typed world.
Another problem is that statically typed languages can have long compile cycles. One C# project I worked on made heavy use of PostSharp, the use of which slowed the compile time to nearly a minute. Additionally, whilst Visual Studio updated the ASP templates in real time, there didn't seem to be a way to reload new DLLs without restarting the development server.
Conversely, when I'm hacking in Clojure, updating the entire system can be done without restarting the server, and takes a fraction of a second.
Macros, too, I guess are easier with dynamic typing. When I write a macro in Clojure, it seems a lot easier than when I was using Template Haskell a few years back. Perhaps there's a better system for macros in a statically typed language, but I haven't run across anything like that yet.
Another problem is that statically typed languages can have long compile cycles.
That only applies if you compile all classes at once. Netbeans (and probably others as well) compile Java classes instantly because they only compile what's changed.
there didn't seem to be a way to reload new DLLs without restarting the development server.
I have seen environments for Java that could reload JAR-files. Perhaps DLLs are different, but that has little to do with a statically typed language.
That only applies if you compile all classes at once.
Unfortunately, a lot of post-processors like PostSharp aren't smart enough to do that. Even though Visual Studio was only compiling once, PostSharp seemed to require a lot of time to do its thing.
I have seen environments for Java that could reload JAR-files. Perhaps DLLs are different, but that has little to do with a statically typed language.
I'd be interested if anyone knows of an environment for a statically typed language that could do this quickly and without losing run-time data.
In a dynamically typed language, altering the server environment at runtime incurs only the cost of evaluating the code. I can inject code at any point, redefine functions, query the state of the current data structures, and so forth. The entire environment is mutable; something that seems like it would be difficult to do with static types.
Statically typed languages tend to lack good REPLs, a tool I consider indispensable. I'm unaware of any statically typed language that has something as complete and integrated as SLIME, for instance. Even a properly setup IRB or IPython don't seem to have anything that matches them in the statically typed world.
Another problem is that statically typed languages can have long compile cycles. One C# project I worked on made heavy use of PostSharp, the use of which slowed the compile time to nearly a minute. Additionally, whilst Visual Studio updated the ASP templates in real time, there didn't seem to be a way to reload new DLLs without restarting the development server.
Conversely, when I'm hacking in Clojure, updating the entire system can be done without restarting the server, and takes a fraction of a second.
Macros, too, I guess are easier with dynamic typing. When I write a macro in Clojure, it seems a lot easier than when I was using Template Haskell a few years back. Perhaps there's a better system for macros in a statically typed language, but I haven't run across anything like that yet.