It's "cost" is in startup times (compiling your code with LLVM at runtime slows things down, no surprise there), and you still have to write somewhat type-stabl

It's "cost" is in startup times (compiling your code with LLVM at runtime slows things down, no surprise there), and you still have to write somewhat type-stable code (outputs uniquely inferrable from inputs) if you want it to actually run full speed.