private static bool IsInternable(OpportunisticIntern.IInternable internable)
{
string i1 = OpportunisticIntern.InternableToString(internable);
string i2 = OpportunisticIntern.InternableToString(internable);
Assert.Equal(i1, i2); // No matter what, the same string value should return.
return(Object.ReferenceEquals(i1, i2));
}
/// <summary>
/// Returns a whitespace-trimmed and possibly interned substring of the expression.
/// </summary>
/// <param name="startIndex">Start index of the substring.</param>
/// <param name="length">Length of the substring.</param>
/// <returns>Equivalent to _expression.Substring(startIndex, length).Trim() or null if the trimmed substring is empty.</returns>
private string GetExpressionSubstring(int startIndex, int length)
{
int endIndex = startIndex + length;
while (startIndex < endIndex && char.IsWhiteSpace(_expression[startIndex]))
{
startIndex++;
}
while (startIndex < endIndex && char.IsWhiteSpace(_expression[endIndex - 1]))
{
endIndex--;
}
if (startIndex < endIndex)
{
var target = new SubstringInternTarget(_expression, startIndex, endIndex - startIndex);
return(OpportunisticIntern.InternableToString(target));
}
return(null);
}