SwitchFunction MakeSwitch(CaseExpression caseExpr)
{
if (caseExpr == null)
{
throw new ArgumentNullException("caseExpr");
}
IExpression left = caseExpr.Case;
SwitchFunction switchFunc = new SwitchFunction();
CaseAlternative alt = caseExpr.Alternatives;
if (alt == null)
{
throw new InvalidOperationException("CASE has no alternatives.");
}
// branch expressions will be tailored through caseExpr.Alternatives
if (left != null)
{
while (alt != null)
{
alt.When = new Expression(left.Clone(), ExpressionOperator.Equal,
alt.When);
CaseAlternative next = alt.Next;
alt.Next = null;
switchFunc.Add(alt);
alt = next;
}
}
else
{
switchFunc.Alternatives = alt;
}
IExpression elseExpr = caseExpr.Else;
if (elseExpr != null)
{
// elseExpr will be tailored through caseExpr.Else
CaseAlternative last = new CaseAlternative(
new Expression(
new IntegerValue(1),
ExpressionOperator.Equal,
new IntegerValue(1)),
elseExpr);
switchFunc.Add(last);
}
return(switchFunc);
}
public override void PerformBefore(CaseAlternative node)
{
if (node == null)
{
throw new ArgumentNullException("node");
}
if (!m_inMSAccessSwitch)
{
m_sql.Append("WHEN ");
}
}
public INode Clone()
{
CaseAlternative caseAlternative = new CaseAlternative(
(IExpression)(m_when.Clone()),
(IExpression)(m_then.Clone()));
if (m_next != null)
{
caseAlternative.Add((CaseAlternative)(m_next.Clone()));
}
return(caseAlternative);
}
public void Add(CaseAlternative tail)
{
if (tail == null)
{
throw new ArgumentNullException("tail");
}
if (m_next == null)
{
m_next = tail;
}
else
{
m_next.Add(tail);
}
}
public override void PerformAfter(CaseAlternative node)
{
if (node == null)
{
throw new ArgumentNullException("node");
}
if (!m_inMSAccessSwitch)
{
m_sql.Append(NewLine);
}
else
{
if (node.HasNext)
{
m_sql.Append(", ");
}
}
}
public virtual void PerformAfter(CaseAlternative node)
{
}
public virtual void PerformOnThen(CaseAlternative node)
{
}
public virtual void PerformBefore(CaseAlternative node)
{
}
public override void PerformAfter(CaseAlternative node)
{
PopKnownParent(node);
}
public override void PerformBefore(CaseAlternative node)
{
PushParent(node);
}