/// <summary>
/// Parse the AST constant node and return Object value.
/// </summary>
/// <param name="node">parse node for which to parse the string value</param>
/// <returns>value matching AST node type</returns>
public static object Parse(IParseTree node)
{
if (node is ITerminalNode)
{
var terminal = (ITerminalNode) node;
switch (terminal.Symbol.Type)
{
case EsperEPL2GrammarParser.BOOLEAN_TRUE:
return BoolValue.ParseString(terminal.GetText());
case EsperEPL2GrammarParser.BOOLEAN_FALSE:
return BoolValue.ParseString(terminal.GetText());
case EsperEPL2GrammarParser.VALUE_NULL:
return null;
default:
throw ASTWalkException.From("Encountered unexpected constant type " + terminal.Symbol.Type, terminal.Symbol);
}
}
var ruleNode = (IRuleNode) node;
var ruleIndex = ruleNode.RuleContext.RuleIndex;
if (ruleIndex == EsperEPL2GrammarParser.RULE_number)
{
return ParseNumber(ruleNode, 1);
}
if (ruleIndex == EsperEPL2GrammarParser.RULE_numberconstant)
{
var number = FindChildRuleByType(ruleNode, EsperEPL2GrammarParser.RULE_number);
if (ruleNode.ChildCount > 1)
{
if (ASTUtil.IsTerminatedOfType(ruleNode.GetChild(0), EsperEPL2GrammarLexer.MINUS))
{
return ParseNumber(number, -1);
}
return ParseNumber(number, 1);
}
return ParseNumber(number, 1);
}
if (ruleIndex == EsperEPL2GrammarParser.RULE_stringconstant)
{
return StringValue.ParseString(node.GetText());
}
if (ruleIndex == EsperEPL2GrammarParser.RULE_constant)
{
return Parse(ruleNode.GetChild(0));
}
throw ASTWalkException.From("Encountered unrecognized constant", node.GetText());
}