public static Value interp(ExprC exp)
{
if (exp.GetType() == typeof(numC))
{
var n = exp as numC;
return(new numV(n.number));
}
else if (exp.GetType() == typeof(binopC))
{
var b = exp as binopC;
var lVal = interp(b.left);
var rVal = interp(b.right);
var lNum = lVal as numV;
var rNum = rVal as numV;
if (b.op == op.Equals("eq?", StringComparison.Ordinal) || b.op == op.Equals("<=", StringComparison.Ordinal))
{
return(booleanBinopHandle(b.op, lNum.number, rNum.number));
}
else if {
return(numBinopHandle(b.op, lNum.number, rNum.number));
}
}
else if (exp.GetType() == typeof(boolC))
{
boolC bC = exp as boolC;
return(boolV(bC.b));
}
else if (exp.GetType() == typeof(ifC))
{
ifC i = exp as ifC;
Value v = interp(i.conditional);
if (v.GetType() == typeof(boolV))
{
boolV bV = v as boolV;
if (bV.b == true)
{
return(interp(i.then));
}
else
{
return(interp(i.els));
}
}
else
{
stringV("interp: error, not a boolV value");
}
}
else
{
LangException ex = new LangException("Not a valid exprC");
throw ex;
}
}
public static Value interp(ExprC exp)
{
if (exp.GetType() == typeof(numC))
{
var n = exp as numC;
return(new numV(n.number));
}
else if (exp.GetType() == typeof(binopC))
{
var b = exp as binopC;
var lVal = interp(b.left);
var rVal = interp(b.right);
var lNum = lVal as numV;
var rNum = rVal as numV;
return(new numV(numBinopHandle(b.op, lNum.number, rNum.number)));
}
else if (exp.GetType() == typeof(boolC))
{
boolC bC = exp as boolC;
return(new boolV(bC.b));
}
else if (exp.GetType() == typeof(ifC))
{
ifC i = exp as ifC;
Value v = interp(i.conditional);
if (v.GetType() == typeof(boolV))
{
boolV bV = v as boolV;
if (bV.b == true)
{
return(interp(i.then));
}
else
{
return(interp(i.els));
}
}
else
{
LangException ex = new LangException("ifC failed");
throw ex;
}
}
else
{
LangException ex = new LangException("Not a valid exprC");
throw ex;
}
}