private object ComputeAssign(BinaryExpr t, IEnvironment env, object rvalue)
{
ASTree l = t.Left;
if (l is Name)
{
env.Put((l as Name).Text, rvalue);
return(rvalue);
}
else if (l is PrimaryExpr)
{
PrimaryExpr p = l as PrimaryExpr;
if (p.HasPostfix(0) && (p.Postfix(0) is Dot))
{
p.Accept(this, env, 1);
object tp = result;
if (result is ErrorValue)
{
return(result);
}
if (tp is RavObject)
{
return(SetField(t, (tp as RavObject), (p.Postfix(0) as Dot), rvalue));
}
}
else if (p.HasPostfix(0) && (p.Postfix(0) is ArrayRef))
{
p.Accept(this, env, 1);
object a = result;
if (result is ErrorValue)
{
return(result);
}
if (a is object[])
{
ArrayRef aref = p.Postfix(0) as ArrayRef;
aref.Index.Accept(this, env);
if (result is ErrorValue)
{
return(result);
}
object index = result;
if (index is int)
{
(a as object[])[(int)index] = rvalue;
return(rvalue);
}
}
result = new ErrorValue("bad array access", t);
return(result);
}
}
return(new ErrorValue("bad assignment", t));
}
private object EvalSubExpr(PrimaryExpr t, IEnvironment env, int nest)
{
if (t.HasPostfix(nest))
{
object target = EvalSubExpr(t, env, nest + 1);
t.Postfix(nest).Accept(this, env, target);
return(result);
}
else
{
t.Operand.Accept(this, env);
return(result);
}
}