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Add index and range polyfills
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‎src/PowerShellEditorServices/Index.cs

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// <auto-generated>
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// Licensed to the .NET Foundation under one or more agreements.
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// The .NET Foundation licenses this file to you under the MIT license.
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using System.Diagnostics.CodeAnalysis;
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using System.Runtime.CompilerServices;
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namespace System
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{
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/// <summary>Represent a type can be used to index a collection either from the start or the end.</summary>
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/// <remarks>
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/// Index is used by the C# compiler to support the new index syntax
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/// <code>
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/// int[] someArray = new int[5] { 1, 2, 3, 4, 5 } ;
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/// int lastElement = someArray[^1]; // lastElement = 5
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/// </code>
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/// </remarks>
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internal readonly struct Index : IEquatable<Index>
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{
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private readonly int _value;
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/// <summary>Construct an Index using a value and indicating if the index is from the start or from the end.</summary>
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/// <param name="value">The index value. it has to be zero or positive number.</param>
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/// <param name="fromEnd">Indicating if the index is from the start or from the end.</param>
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/// <remarks>
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/// If the Index constructed from the end, index value 1 means pointing at the last element and index value 0 means pointing at beyond last element.
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/// </remarks>
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public Index(int value, bool fromEnd = false)
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{
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if (value < 0)
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{
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ThrowHelper.ThrowValueArgumentOutOfRange_NeedNonNegNumException();
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}
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if (fromEnd)
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_value = ~value;
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else
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_value = value;
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}
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// The following private constructors mainly created for perf reason to avoid the checks
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private Index(int value) => _value = value;
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/// <summary>Create an Index pointing at first element.</summary>
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public static Index Start => new Index(0);
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/// <summary>Create an Index pointing at beyond last element.</summary>
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public static Index End => new Index(~0);
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/// <summary>Create an Index from the start at the position indicated by the value.</summary>
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/// <param name="value">The index value from the start.</param>
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static Index FromStart(int value)
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{
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if (value < 0)
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{
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ThrowHelper.ThrowValueArgumentOutOfRange_NeedNonNegNumException();
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}
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return new Index(value);
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}
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/// <summary>Create an Index from the end at the position indicated by the value.</summary>
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/// <param name="value">The index value from the end.</param>
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static Index FromEnd(int value)
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{
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if (value < 0)
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{
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ThrowHelper.ThrowValueArgumentOutOfRange_NeedNonNegNumException();
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}
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return new Index(~value);
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}
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/// <summary>Returns the index value.</summary>
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public int Value
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{
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get
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{
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if (_value < 0)
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return ~_value;
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else
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return _value;
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}
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}
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/// <summary>Indicates whether the index is from the start or the end.</summary>
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public bool IsFromEnd => _value < 0;
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/// <summary>Calculate the offset from the start using the giving collection length.</summary>
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/// <param name="length">The length of the collection that the Index will be used with. length has to be a positive value</param>
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/// <remarks>
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/// For performance reason, we don't validate the input length parameter and the returned offset value against negative values.
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/// we don't validate either the returned offset is greater than the input length.
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/// It is expected Index will be used with collections which always have non negative length/count. If the returned offset is negative and
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/// then used to index a collection will get out of range exception which will be same affect as the validation.
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/// </remarks>
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public int GetOffset(int length)
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{
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int offset = _value;
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if (IsFromEnd)
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{
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// offset = length - (~value)
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// offset = length + (~(~value) + 1)
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// offset = length + value + 1
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offset += length + 1;
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}
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return offset;
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}
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/// <summary>Indicates whether the current Index object is equal to another object of the same type.</summary>
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/// <param name="value">An object to compare with this object</param>
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public override bool Equals([NotNullWhen(true)] object? value) => value is Index && _value == ((Index)value)._value;
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/// <summary>Indicates whether the current Index object is equal to another Index object.</summary>
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/// <param name="other">An object to compare with this object</param>
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public bool Equals(Index other) => _value == other._value;
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/// <summary>Returns the hash code for this instance.</summary>
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public override int GetHashCode() => _value;
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/// <summary>Converts integer number to an Index.</summary>
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public static implicit operator Index(int value) => FromStart(value);
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/// <summary>Converts the value of the current Index object to its equivalent string representation.</summary>
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public override string ToString()
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{
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if (IsFromEnd)
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return ToStringFromEnd();
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return ((uint)Value).ToString();
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}
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private string ToStringFromEnd()
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{
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return '^' + Value.ToString();
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}
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internal static class ThrowHelper
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{
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[DoesNotReturn, MethodImpl(MethodImplOptions.NoInlining)]
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public static void ThrowValueArgumentOutOfRange_NeedNonNegNumException()
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{
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throw new ArgumentOutOfRangeException(
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"Non-negative number required. (Parameter 'value')",
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"value");
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}
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}
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}
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}

‎src/PowerShellEditorServices/Range.cs

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// <auto-generated>
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// Licensed to the .NET Foundation under one or more agreements.
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// The .NET Foundation licenses this file to you under the MIT license.
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global using Range = OmniSharp.Extensions.LanguageServer.Protocol.Models.Range;
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#nullable enable
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using System.Diagnostics.CodeAnalysis;
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using System.Runtime.CompilerServices;
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namespace System
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{
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/// <summary>Represent a range has start and end indexes.</summary>
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/// <remarks>
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/// Range is used by the C# compiler to support the range syntax.
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/// <code>
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/// int[] someArray = new int[5] { 1, 2, 3, 4, 5 };
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/// int[] subArray1 = someArray[0..2]; // { 1, 2 }
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/// int[] subArray2 = someArray[1..^0]; // { 2, 3, 4, 5 }
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/// </code>
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/// </remarks>
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internal readonly struct Range : IEquatable<Range>
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{
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/// <summary>Represent the inclusive start index of the Range.</summary>
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public Index Start { get; }
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/// <summary>Represent the exclusive end index of the Range.</summary>
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public Index End { get; }
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/// <summary>Construct a Range object using the start and end indexes.</summary>
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/// <param name="start">Represent the inclusive start index of the range.</param>
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/// <param name="end">Represent the exclusive end index of the range.</param>
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public Range(Index start, Index end)
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{
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Start = start;
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End = end;
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}
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/// <summary>Indicates whether the current Range object is equal to another object of the same type.</summary>
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/// <param name="value">An object to compare with this object</param>
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public override bool Equals([NotNullWhen(true)] object? value) =>
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value is Range r &&
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r.Start.Equals(Start) &&
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r.End.Equals(End);
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/// <summary>Indicates whether the current Range object is equal to another Range object.</summary>
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/// <param name="other">An object to compare with this object</param>
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public bool Equals(Range other) => other.Start.Equals(Start) && other.End.Equals(End);
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/// <summary>Returns the hash code for this instance.</summary>
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public override int GetHashCode()
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{
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return (Start.GetHashCode(), End.GetHashCode()).GetHashCode();
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}
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/// <summary>Converts the value of the current Range object to its equivalent string representation.</summary>
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public override string ToString()
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{
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return Start.ToString() + ".." + End.ToString();
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}
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/// <summary>Create a Range object starting from start index to the end of the collection.</summary>
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public static Range StartAt(Index start) => new Range(start, Index.End);
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/// <summary>Create a Range object starting from first element in the collection to the end Index.</summary>
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public static Range EndAt(Index end) => new Range(Index.Start, end);
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/// <summary>Create a Range object starting from first element to the end.</summary>
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public static Range All => new Range(Index.Start, Index.End);
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/// <summary>Calculate the start offset and length of range object using a collection length.</summary>
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/// <param name="length">The length of the collection that the range will be used with. length has to be a positive value.</param>
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/// <remarks>
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/// For performance reason, we don't validate the input length parameter against negative values.
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/// It is expected Range will be used with collections which always have non negative length/count.
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/// We validate the range is inside the length scope though.
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/// </remarks>
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public (int Offset, int Length) GetOffsetAndLength(int length)
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{
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int start;
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Index startIndex = Start;
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if (startIndex.IsFromEnd)
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start = length - startIndex.Value;
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else
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start = startIndex.Value;
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int end;
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Index endIndex = End;
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if (endIndex.IsFromEnd)
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end = length - endIndex.Value;
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else
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end = endIndex.Value;
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if ((uint)end > (uint)length || (uint)start > (uint)end)
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{
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ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.length);
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}
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return (start, end - start);
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}
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private static class ExceptionArgument
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{
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public const string length = nameof(length);
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}
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private static class ThrowHelper
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{
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[DoesNotReturn, MethodImpl(MethodImplOptions.NoInlining)]
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public static void ThrowArgumentOutOfRangeException(string parameterName)
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{
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throw new ArgumentOutOfRangeException(parameterName);
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}
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}
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}
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}

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