protected override bool IsPossibleNextPart(PartRuleType nextType)
{
if (IsOptimalNextPart(nextType))
{
return(true);
}
return(nextType == PartRuleType.AddSub || nextType == PartRuleType.OneValueFunction);
}
protected override bool WasAbleToChangeIfNecessary(Parts parts,
int thisIndex, PartRuleType nextType)
{
if (nextType == PartRuleType.Start || nextType == PartRuleType.Value ||
nextType == PartRuleType.OneValueFunction)
{
parts.Insert(thisIndex + 1, new PartMult());
return(true);
}
return(false);
}
public void CheckIfPossibleNextPart(Parts parts)
{
while (true)
{
int thisIndex = parts.ExtendedIndexOf(this);
PartRuleType nextType = parts[thisIndex + 1].GetRuleType();
if (IsOptimalNextPart(nextType))
{
return;
}
if (!IsPossibleNextPart(nextType) || !WasAbleToChangeIfNecessary(parts, thisIndex, nextType))
{
throw new ArgumentException();
}
}
}
protected abstract bool WasAbleToChangeIfNecessary(Parts parts, int thisIndex, PartRuleType nextType);
protected abstract bool IsOptimalNextPart(PartRuleType nextType);
protected abstract bool IsPossibleNextPart(PartRuleType nextType);
protected override bool IsOptimalNextPart(PartRuleType nextType)
{
return(nextType == PartRuleType.AddSub || nextType == PartRuleType.End ||
nextType == PartRuleType.MultDiv || nextType == PartRuleType.TwoValueFunction);
}
protected override bool IsOptimalNextPart(PartRuleType nextType)
{
return(nextType == PartRuleType.OneValueFunction ||
nextType == PartRuleType.Start || nextType == PartRuleType.Value);
}
protected override bool WasAbleToChangeIfNecessary(Parts parts, int thisIndex, PartRuleType nextType)
{
if (nextType == PartRuleType.AddSub)
{
((PartAddSub)parts[thisIndex + 1]).ChangeToPartSignIfSub(parts);
return(true);
}
return(false);
}
protected override bool WasAbleToChangeIfNecessary(Parts parts, int thisIndex, PartRuleType nextType)
{
Part nextPart = parts[thisIndex + 1];
if (!(nextPart is PartAddSub))
{
return(false);
}
((PartAddSub)nextPart).ChangeToPartSignIfSub(parts);
return(true);
}
protected override bool IsPossibleNextPart(PartRuleType nextType)
{
return(nextType == PartRuleType.AddSub || IsOptimalNextPart(nextType));
}
