public override void PerformBefore(Interval node)
{
if (node == null)
{
throw new ArgumentNullException("node");
}
base.PerformBefore(node);
IntegerValue integerValue = node.Value as IntegerValue;
if (integerValue == null)
{
throw new InvalidOperationException(
"Non-constant interval cannot be stringified.");
}
if (!node.Positive)
{
node.Value = node.GetSignedValue();
node.Positive = true;
}
decimal v = integerValue.Value;
if (v < 0)
{
v = -1 * v;
}
string s = Convert.ToString(v);
int requiredPrecision = s.Length;
if (requiredPrecision < Interval.ImplicitPrecision)
{
requiredPrecision = Interval.ImplicitPrecision;
}
if (node.Precision < requiredPrecision)
{
node.Precision = requiredPrecision;
}
}
/// <summary>
/// Constructs the last argument for substring functions.
/// </summary>
/// <param name="startExpr">
/// First argument of the substring function
/// (<c>ExpressionItem.Expression</c>, not the top-level <c>ExpressionItem</c>).
/// </param>
/// <param name="valExpr">
/// Second argument of the substring function
/// (<c>ExpressionItem.Expression</c>, not the top-level <c>ExpressionItem</c>).
/// </param>
/// <param name="lenName">
/// Name of the length function (must not be null).
/// </param>
public static IExpression MakeLenArg(INode startExpr, INode valExpr,
string lenName)
{
if (startExpr == null)
{
throw new ArgumentNullException("startExpr");
}
if (valExpr == null)
{
throw new ArgumentNullException("valExpr");
}
if (lenName == null)
{
throw new ArgumentNullException("lenName");
}
FunctionCall lenCall = new FunctionCall(lenName);
lenCall.ExpressionArguments = new ExpressionItem(valExpr.Clone());
IExpression argument;
INode startTerm = GetTerm(startExpr);
IntegerValue integerValue = startTerm as IntegerValue;
if ((integerValue != null) && (integerValue.Value == 1))
{
argument = lenCall;
}
else
{
Expression left = new Expression(lenCall,
ExpressionOperator.Plus,
new IntegerValue(1));
argument = new Expression(left,
ExpressionOperator.Minus,
startTerm.Clone());
}
return(argument);
}
/// <summary>
/// The value of this interval.
/// </summary>
public INode GetSignedValue()
{
if (m_positive)
{
return(m_value.Clone());
}
else
{
IntegerValue integerValue = m_value as IntegerValue;
if (integerValue != null)
{
return(new IntegerValue(-1 * integerValue.Value));
}
else
{
return(new Expression(
new IntegerValue(-1),
ExpressionOperator.Mult,
m_value.Clone()));
}
}
}
public virtual void Perform(IntegerValue node)
{
}
public static ExpressionItem MakeLiteralInteger(int literal)
{
IntegerValue integerValue = new IntegerValue(literal);
return(new ExpressionItem(integerValue));
}