I am not really well versed in Haskell debugging, but a thought.. Current debuggers are built around very imperative notion of program state. I have breakpoint

I am not really well versed in Haskell debugging, but a thought.. Current debuggers are built around very imperative notion of program state. I have breakpoints, I can look at variables (state in a given time).. What would debugging look like if we looked at it from the functional perspective? For example, execution "filters" instead of breakpoints. What happens if this function receives value that satisfies certain condition? Instead of variable watches, give out a breakdown of the data passed in and out from the function. Etc.