private object AssignTuple(Environment env, TupleNode left, string op, object rvalue)
{
if (left == null)
{
throw new ArgumentNullException(nameof(left), "null left tuple");
}
Tuple right = rvalue as Tuple;
if (right != null)
{
object result = 0;
int count = 0;
foreach (IAstNode node in left)
{
if (count >= right.Count)
{
break;
}
TupleNode tuple = node as TupleNode;
if (node != null)
{
result = AssignTuple(env, tuple, op, right[count++]);
}
else
{
FactorNode factor = node as FactorNode;
if (factor == null || !factor.IsAssignable)
{
throw new LepException("bad assignment", this);
}
PrimaryNode primary = factor.Operand as PrimaryNode;
if (primary == null)
{
throw new LepException("bad assignment", this);
}
if (((NameNode)primary.Operand).IsAnonymous)
{
++count;
}
else
{
result = Assign(env, primary, op, right[count++], factor.AssignType);
}
}
}
return(result);
}
else
{
throw new LepException("bad assignment", this);
}
}
private object Assign(Environment env, PrimaryNode left, string op, object rvalue, int type)
{
if (env == null) throw new ArgumentNullException(nameof(env), "null environment");
if (left == null) throw new ArgumentNullException(nameof(left), "null left name");
if (op == null) throw new ArgumentNullException(nameof(op), "null operator");
if (left.IsName)
{
NameNode var = (NameNode)left.Operand;
if (op == "=")
{
env.Set(var.Name, rvalue, type);
return rvalue;
}
else
{
object name = env.Get(var.Name, type);
if (name == null) throw new LepException("undefined name: " + var.Name, this);
else
{
object result = ComputeOperator(name, op.Substring(0, op.Length - 1), rvalue);
env.Set(var.Name, result, type);
return result;
}
}
}
else
{
ArrayReferenceNode arrRef = left.Suffix(0) as ArrayReferenceNode;
if (arrRef != null)
{
object lvalue = left.EvaluateSub(env, 1, type);
object[] arr = lvalue as object[];
if (arr != null)
{
object index = arrRef.Index.Evaluate(env);
if (index is int) return arr[(int)index] = rvalue;
}
Dictionary<object, object> table = lvalue as Dictionary<object, object>;
if (table != null)
{
object index = arrRef.Index.Evaluate(env);
return table[index] = rvalue;
}
}
}
throw new LepException("bad assignment", this);
}
public void Evaluate(Environment env, int index, object value)
{
if (env == null)
{
throw new ArgumentNullException(nameof(env), "null environment");
}
IAstNode current = Parameter(index);
FactorNode factor = current as FactorNode;
if (factor == null || !factor.IsNoPrefixPrimary)
{
throw new LepException("bad parameter");
}
PrimaryNode primary = factor.Operand as PrimaryNode;
if (primary == null || !primary.IsName)
{
throw new LepException("bad parameter");
}
NameNode name = primary.Operand as NameNode;
if (name == null)
{
throw new LepException("bad parameter");
}
if (name.IsAnonymous)
{
return;
}
env.Set(name.Token.Text, value, Environment.LocalVariable);
}
private object Assign(Environment env, PrimaryNode left, string op, object rvalue, int type)
{
if (env == null)
{
throw new ArgumentNullException(nameof(env), "null environment");
}
if (left == null)
{
throw new ArgumentNullException(nameof(left), "null left name");
}
if (op == null)
{
throw new ArgumentNullException(nameof(op), "null operator");
}
if (left.IsName)
{
NameNode var = (NameNode)left.Operand;
if (op == "=")
{
env.Set(var.Name, rvalue, type);
return(rvalue);
}
else
{
object name = env.Get(var.Name, type);
if (name == null)
{
throw new LepException("undefined name: " + var.Name, this);
}
else
{
object result = ComputeOperator(name, op.Substring(0, op.Length - 1), rvalue);
env.Set(var.Name, result, type);
return(result);
}
}
}
else
{
ArrayReferenceNode arrRef = left.Suffix(0) as ArrayReferenceNode;
if (arrRef != null)
{
object lvalue = left.EvaluateSub(env, 1, type);
object[] arr = lvalue as object[];
if (arr != null)
{
object index = arrRef.Index.Evaluate(env);
if (index is int)
{
return(arr[(int)index] = rvalue);
}
}
Dictionary <object, object> table = lvalue as Dictionary <object, object>;
if (table != null)
{
object index = arrRef.Index.Evaluate(env);
return(table[index] = rvalue);
}
}
}
throw new LepException("bad assignment", this);
}
