void HandleMessage(IQueryMsg e)
{
var expr = VerifiedExpression.Parse(e.Message, CalcEnv);
// Only automatically calculate if the expression is legitimate and if it's reasonable to assume it's meant
// to be a calculation (not just a single number). A minimal calculation will involve at least 3 tokens:
// `number operator number`.
const int minTokenCount = 3;
if (expr.Success && expr.Expression.Count >= minTokenCount)
{
double result = ShuntingYard.Calculate(expr);
e.Reply(result.ToString());
}
}
static bool CheckPreconditions(ITriggerMsg e, VerifiedExpression expr, string symbol)
{
if (!expr.Success)
{
OutputError(e, expr);
return(false);
}
if (!Verifier.VerifySymbol(symbol))
{
e.Reply("Symbol contains illegal characters.");
return(false);
}
return(true);
}
void HandleTrigger(ITriggerMsg e)
{
var exprStr = e.MessageWithoutTrigger();
if (exprStr.HasValue())
{
var expr = VerifiedExpression.Parse(exprStr, CalcEnv);
if (expr.Success)
{
double result = ShuntingYard.Calculate(expr);
e.Reply(result.ToString());
}
else
{
OutputError(e, expr);
}
}
}
void DefVar(ITriggerMsg e)
{
var expression = e.GetArg(out string symbol).ToJoined();
if (ParseArgs.Success(symbol, expression))
{
var expr = VerifiedExpression.Parse(expression, CalcEnv);
if (CheckPreconditions(e, expr, symbol))
{
double result = ShuntingYard.Calculate(expr);
if (CalcEnv.Variable(symbol, out double previous))
{
e.Reply("{0} = {1} (Previous value: {2})", symbol, result, previous);
}
else
{
e.Reply("{0} = {1}", symbol, result);
}
CalcEnv.AssignVariable(symbol, result);
}
}
}
