Debugging F# code and functional style

Question

I'm new to funcctional programming and have some questions regarding coding style and debugging.

I'm under the impression that one should avoid storing results from funcction calls in a temp variable and then return that variable

e.g.

let someFunc foo =     let result = match foo with                  | x -> ...                  | y -> ...     result  

And instead do it like this (I might be way off?):

let someFunc foo =     match foo with     | x -> ...     | y -> ... 

Which works fine from a functionallity perspective, but it makes it way harder to debug. I have no way to examine the result if the right hand side of -> does some funky stuff.

So how should I deal with this kind of scenarios?

Answer 1

To inspect the middle of a pipeline, I suggest the following workaround:

Put this code at some place:

[<AutoOpen>] module AutoOpenModule  #if DEBUG let (|>) value func =   let result = func value   result #endif 

Enable "Step Into Properties and Operators in Managed Code":

https://msdn.microsoft.com/en-us/library/cc667388(v=vs.100).aspx

Now you should be able to step into the pipeline operator.