static object ComputationValue(Racr.AstNode n) {
var op = n.GetOperator();
var operands = n.GetOperands().Children();
var args = operands.Select(p => ((Racr.AstNode) p).Value()).ToArray();
var func = opTable[op];
try { return func(args); }
catch { return null; }
}
static string ComputationSExpr(Racr.AstNode n) {
return "(~~ " + n.GetOperator() + " " + String.Join(" ", n.GetOperands().Children().Select(x => ((Racr.AstNode)x).SExpr())) + ")";
}
static ValueTypes ComputationType(Racr.AstNode n) {
var op = n.GetOperator();
var inType = ValueTypes.ErrorType;
var outType = ValueTypes.ErrorType;
var operands = n.GetOperands().Children();
if (op == "&&" || op == "//" || op == "not") inType = outType = ValueTypes.Boolean;
else if (op == "=" || op == "<" || op == ">" || op == "<=" || op == ">=" || op == "!=") {
inType = ValueTypes.Number;
outType = ValueTypes.Boolean;
}
else if (op == "string=?" || op == "string<?" || op == "string>?" || op == "string<=?" || op == "string>=?") {
inType = ValueTypes.String;
outType = ValueTypes.Boolean;
}
else if (op == "+" || op == "-" || op == "*" || op == "/") inType = outType = ValueTypes.Number;
else if (op == "string-append") inType = outType = ValueTypes.String;
if (operands.Any(x => ((Racr.AstNode) x).Type() != inType)) return ValueTypes.ErrorType;
return outType;
}