private static Expression BelongsToInverseInterval(Expression variable, Expression from, Expression to)
{
var greaterThanOrEqualTo = DynamicBuilder.BuildOperator(ExpressionType.GreaterThanOrEqual, variable, to);
var lessThanOrEqualFrom = DynamicBuilder.BuildOperator(ExpressionType.LessThanOrEqual, variable, from);
return(DynamicBuilder.BuildLogicalAnd(greaterThanOrEqualTo, lessThanOrEqualFrom));
}
public void TakeStep()
{
var addStep = DynamicBuilder.BuildOperator(ExpressionType.Add, Variable, Step);
var convert = DynamicBuilder.BuildConvert(addStep, typeof(object));
var assign = Expression.Assign(Variable, convert);
assign.RunAndDropValue();
IsOver = !IsBelongsToInterval(Variable, From, To);
}
/// <summary>
/// Determines whether the variable belongs to the specified interval.
/// </summary>
/// <remarks>The method checks for both <c>[from, to]</c> and <c>[to, from]</c> intervals.</remarks>
/// <param name="variable">The variable expression.</param>
/// <param name="from">The start bound expression.</param>
/// <param name="to">The end bound expression.</param>
/// <returns><c>true</c> if the variable belongs to the interval; otherwise, <c>false</c>.</returns>
internal static bool IsBelongsToInterval(Expression variable, Expression from, Expression to)
{
var isBelongsToDirectInterval = BelongsToDirectInterval(variable, from, to);
var isBelongsToInverseInterval = BelongsToInverseInterval(variable, from, to);
var result = DynamicBuilder.BuildLogicalOr(isBelongsToDirectInterval, isBelongsToInverseInterval);
var resultAsBool = (bool)DynamicBuilder.BuildConvert(result, typeof(bool))
.Calculate();
return(resultAsBool);
}