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ObjectDisposedException with "Cannot read from a closed TextReader".
f#

In VS2100 with F# 2.0 I try to process a file. Unfortunately I get an ObjectDisposedException with "Cannot read from a closed TextReader".

My Code:

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// Process one data line and return a point = a tuple of floats (Simple demo version)

let getPoint (line : string) =

    let parts = line.Split(',')

    (float parts.[0], float parts.[1])

// Calculate the center of the point sequence

let getCenter (points : seq<(float * float)>) = 

   let xPoints = Seq.map fst points

   let yPoints = Seq.map snd points

   (Seq.average xPoints, Seq.average yPoints)

// Process a file

let nmea2xol filePath =

  let (lines : seq<string>) = System.IO.File.ReadLines(filePath) 

  let points = Seq.map getPoint lines

  let center = getCenter points

  // Do additional stuff with these points

  ()

// A simple test

do  nmea2xol @"C:\Temp\Test.txt" done

An example of my test data: "C:\Temp\Test.txt"

12.4,13.8

14.7,2.5

23.9,2.4

18.9,36.5

The error occurs in the Seq.average function. Why?

.

ReadLines is lazy and can read the file once.

ReadAllLines is eager and reads to an array which you can traverse as much as you like.

[link:msdn.microsoft.com]

You are using ReadLines (lazy seq), and then try to traverse it twice (xPoints and yPoints).

Just use ReadAllLines.

By on 5/15/2010 2:27 AM ()

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