private BoundExpression BindCoalesceExpression(CoalesceExpressionSyntax node)
{
// COALESCE(e1, e2, .. eN)
//
// ====>
//
// CASE
// WHEN e1 IS NOT NULL THEN e1
// ..
// WHEN e2 IS NOT NULL THEN e2
// ELSE
// eN
// END
var boundArguments = BindToCommonType(node.ArgumentList.Arguments);
var caseLabelCount = node.ArgumentList.Arguments.Count - 1;
var caseLabels = new BoundCaseLabel[caseLabelCount];
for (var i = 0; i < caseLabelCount; i++)
{
var argument = node.ArgumentList.Arguments[i];
var boundArgument = boundArguments[i];
var boundIsNullExpression = new BoundIsNullExpression(boundArgument);
var boundIsNullNegation = BindUnaryExpression(argument.Span, UnaryOperatorKind.LogicalNot, boundIsNullExpression);
var caseLabel = new BoundCaseLabel(boundIsNullNegation, boundArgument);
caseLabels[i] = caseLabel;
}
var elseExpresion = boundArguments.Last();
return(new BoundCaseExpression(caseLabels, elseExpresion));
}
public virtual void VisitCoalesceExpression(CoalesceExpressionSyntax node)
{
DefaultVisit(node);
}
public virtual TResult VisitCoalesceExpression(CoalesceExpressionSyntax node)
{
return(DefaultVisit(node));
}
