Back to Questions
1.1k
views4
comments
F# debugging: Function evaluation timed out
f#

Hi,

I am debugging an app, when I try to

look at the contents of a Seq (Int, Float) in

the Watch window, I get 'Function

Evaluation Timed Out'. What gives?

Is there any other way of examining the contents of the data structures?

Thanks!

--Sanatan

.

Sequences (IEnumerable<T>) are lazy, so the code that back this sequence apparently took too long to run or got stuck in a loop (the VS debugger protects itself from 'hanging' when it tries to display data that causes evaluation of user code as a side-effect). If the variable is named 's', you might try typing e.g. "System.Linq.Enumerable.First(s)" in the immediate window to attempt to inspect the first element, but this sounds like a case where you might have better luck just reading the code that produced this 'seq' and seeing if it is doing something slow or getting caught in a loop.

By on 1/29/2009 9:35 AM ()

That doesn't seem to be the case. My code looks like:

let timeSeries = getData setName

let heights = timeSeries |> filter1

let weights = timeSeries |> filter2

(* Some processing on heights and weights *)

System.Console.WriteLine(heightsSummary |> prettyPrinter)

System.Console.WriteLine(weightsSummary |> prettyPrinter)

So what is happening is that I can examine the contents of heightsSummary, but not that of heights or weights. So the problem cannot be laziness, since the availability of data in heightsSummary implies that the data fetch step completed.

Of course, everything gets printed correctly, if let the programme run.

--Sanatan

By on 1/30/2009 2:10 AM ()

One thing to consider is to define

1
2

let DisplaySeq s = Seq.to_list s |> sprintf "%A"

at the top of your program and then use "DisplaySeq(heights)" in the Immediate Window of VS to inspect the data.

I found this page that describes (and has links to much more information) the 'Function Evaluation Timed Out' message:

[link:blogs.msdn.com]

but I dunno how it applies to your situation.

By on 1/30/2009 3:24 AM ()

Hmm...I did come across that page via Google, but not all that helpful.

I've gone back to print statements.

Thanks so much for helping out!

--Sanatan

By on 2/2/2009 5:51 AM ()

    Topic tags

    IntelliFactory Offices Copyright (c) 2011-2012 IntelliFactory. All rights reserved.
    Home | Products | Consulting | Trainings | Blogs | Jobs | Contact Us | Terms of Use | Privacy Policy | Cookie Policy     		Built with WebSharper