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Possible Bug Defining Complex types
f#

I get an error with the following code. Please let me know what I'm doing wrong. (I'm using the may 2009 CTP)

#light

open System

open System.Collections.Generic;

type Range =

val signature: string;

val leftPos:int;

val rightPos:int;

val inWindow:bool;

member x.Signature = x.signature

member x.LeftPos = x.leftPos

member x.RightPos = x.rightPos

member x.InWindow = x.inWindow

type Window =

val rangeItem:Range //this is the offending line error goes away if commented out

val leftWindowRangeIndex : int

val rightWindowRangeIndex : int

new() = { leftWindowRangeIndex=0; //this line shows error

rightWindowRangeIndex=0; }

.

The constructor for the Window type is required to initialize all explicit fieldws (ie. "val"s) which are not marked [<DefaultValue>], and you have not initialized the rangeItem field.

So you can:

either add [<DefaultValue>] to the rangeItem, ie.

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    [<DefaultValue>]
    val rangeItem:Range;

Or initialize the rangeItem in the new() for Window... (I'll post the whole solution, with formatting.)

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open System

open System.Collections.Generic;

type Range =
    val signature: string;
    val leftPos:int;
    val rightPos:int;
    val inWindow:bool;
    member x.Signature = x.signature
    member x.LeftPos = x.leftPos
    member x.RightPos = x.rightPos
    member x.InWindow = x.inWindow
    // ADD CONSTRUCTOR
    new() = { signature = ""; leftPos = 0; rightPos = 0; inWindow = false; }

type Window =
    val rangeItem:Range; //this is the offending line error goes away if commented out
    val leftWindowRangeIndex : int;
    val rightWindowRangeIndex : int;
    new() = { leftWindowRangeIndex=0; //this line shows error
                rightWindowRangeIndex=0;
                rangeItem = new Range(); } // INITIALIZE rangeItem

See Explicit Fields in MSDN

To format F# code in this forum, use the F# button in the tools for message editing (second row), or insert

By on 9/30/2009 3:40 AM ()

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