public static IList <ExprNode> GetExprNodesLibFunc(EsperEPL2GrammarParser.LibFunctionArgsContext ctx, IDictionary <ITree, ExprNode> astExprNodeMap)
{
if (ctx == null)
{
return(Collections.GetEmptyList <ExprNode>());
}
IList <EsperEPL2GrammarParser.LibFunctionArgItemContext> args = ctx.libFunctionArgItem();
if (args == null || args.IsEmpty())
{
return(Collections.GetEmptyList <ExprNode>());
}
IList <ExprNode> parameters = new List <ExprNode>(args.Count);
foreach (var arg in args)
{
if (arg.expressionLambdaDecl() != null)
{
var lambdaparams = GetLambdaGoesParams(arg.expressionLambdaDecl());
var goes = new ExprLambdaGoesNode(lambdaparams);
var lambdaExpr = ASTExprHelper.ExprCollectSubNodes(arg.expressionWithNamed(), 0, astExprNodeMap)[0];
goes.AddChildNode(lambdaExpr);
parameters.Add(goes);
}
else
{
var parameter = ASTExprHelper.ExprCollectSubNodes(arg.expressionWithNamed(), 0, astExprNodeMap)[0];
parameters.Add(parameter);
}
}
return(parameters);
}
// Min/Max nodes can be either an aggregate or a per-row function depending on the number or arguments
private static void HandleMinMax(
string ident,
EsperEPL2GrammarParser.LibFunctionArgsContext ctxArgs,
IDictionary <ITree, ExprNode> astExprNodeMap)
{
// Determine min or max
var childNodeText = ident;
MinMaxTypeEnum minMaxTypeEnum;
var filtered = childNodeText.StartsWith("f");
if (childNodeText.ToLowerInvariant().Equals("min") || childNodeText.ToLowerInvariant().Equals("fmin"))
{
minMaxTypeEnum = MinMaxTypeEnum.MIN;
}
else if (childNodeText.ToLowerInvariant().Equals("max") || childNodeText.ToLowerInvariant().Equals("fmax"))
{
minMaxTypeEnum = MinMaxTypeEnum.MAX;
}
else
{
throw ASTWalkException.From("Uncountered unrecognized min or max node '" + ident + "'");
}
var args = Collections.GetEmptyList <ExprNode>();
if (ctxArgs != null && ctxArgs.libFunctionArgItem() != null)
{
args = ASTExprHelper.ExprCollectSubNodes(ctxArgs, 0, astExprNodeMap);
}
var numArgsPositional = ExprAggregateNodeUtil.CountPositionalArgs(args);
var isDistinct = ctxArgs != null && ctxArgs.DISTINCT() != null;
if (numArgsPositional > 1 && isDistinct && !filtered)
{
throw ASTWalkException.From(
"The distinct keyword is not valid in per-row min and max " +
"functions with multiple sub-expressions");
}
ExprNode minMaxNode;
if (!isDistinct && numArgsPositional > 1 && !filtered)
{
// use the row function
minMaxNode = new ExprMinMaxRowNode(minMaxTypeEnum);
}
else
{
// use the aggregation function
minMaxNode = new ExprMinMaxAggrNode(isDistinct, minMaxTypeEnum, filtered, false);
}
minMaxNode.AddChildNodes(args);
astExprNodeMap.Put(ctxArgs, minMaxNode);
}
