/// <summary>
/// Deal with a constant expression. Exactly how this is dealt with depends on the value. We process
/// the most important ones directly, and the MEF-off the others. :-)
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
protected override Expression VisitConstant(ConstantExpression expression)
{
if (expression.Type == typeof(int) ||
expression.Type == typeof(uint))
{
_result = new ValSimple(expression.Value.ToString(), expression.Type, null);
}
else if (expression.Type == typeof(float) ||
expression.Type == typeof(double))
{
// Make sure it is a legal expression.
if ((expression.Type == typeof(double) && (double.IsNaN((double)expression.Value) || double.IsInfinity((double)expression.Value))) ||
(expression.Type == typeof(float) && (float.IsNaN((float)expression.Value) || float.IsInfinity((float)expression.Value))))
{
throw new ArgumentException($"Can't translate {expression.Value.ToString()} to C++. Illegal number.");
}
var s = expression.Value.ToString();
if (!s.Contains("."))
{
s += ".0";
}
_result = new ValSimple(s, expression.Type, null);
}
else if (expression.Type == typeof(bool))
{
if ((bool)expression.Value)
{
_result = new ValSimple("true", typeof(bool), null);
}
else
{
_result = new ValSimple("false", typeof(bool), null);
}
}
else if (expression.Type == typeof(string))
{
_result = new ConstantString(expression.Value as string);
}
else if (expression.Value == null)
{
_result = new ValSimple("0", expression.Type, null);
}
else
{
_result = TypeHandlers.ProcessConstantReference(expression, _codeEnv, MEFContainer);
}
return(expression);
}
