public Cell Visit(GridValueNode node)
{
MathExpressionAstEvaluator exprVisitor = new MathExpressionAstEvaluator();
int x = exprVisitor.Visit(node.FirstD);
int y = exprVisitor.Visit(node.SecondD);
// Wrap around if out of bounds
while (x >= sender.X_Max)
{
x -= sender.X_Max;
}
while (x < 0)
{
x += sender.X_Max;
}
while (y >= sender.Y_Max)
{
y -= sender.Y_Max;
}
while (y < 0)
{
y += sender.Y_Max;
}
return(sender.GetCell(new Pos(x, y)));
}
public void Visit(AdvancedReturnStatementNode node)
{
ValueAstEvaluator valueEvaluator = new ValueAstEvaluator(sender);
MathExpressionAstEvaluator exprEvaluator = new MathExpressionAstEvaluator();
Cell cell = sender.GetCurrentCell();
Symbol sym = Stbl.st.Retrieve(node.Identifier.Label);
if (sym is StateSymbol s)
{
try
{
// Set state members
StateSymbol state = s.Copy();
foreach (ReturnMemberNode rNode in node.ReturnMembers)
{
MemberSymbol member = state.RetrieveMember(rNode.ID.Label);
switch (rNode.Value)
{
case ExpressionNode valueNode: member.SetValue(exprEvaluator.Visit(valueNode)); break;
case StringValueNode valueNode: member.SetValue(valueNode.Value); break;
default: throw new TheLanguageErrorException($"ReturnMember value cannot be of type \'{ rNode.Value.GetType().Name }\'");
}
}
sender.SetCell(cell, state);
}
catch (TheLanguageErrorException e) { throw new TheLanguageErrorException($"Return statement \'{ node.Identifier.Label }\'", e); }
}
else
{
throw new TheLanguageErrorException($"Return statement. Unexpected type { sym } expected State");
}
sender.ReturnStatementHasBeenHit = true;
}
public void Visit(MemberAssignmentStatementNode node)
{
ValueAstEvaluator valueEvaluator = new ValueAstEvaluator(sender);
Cell cell;
// Get cell
if (node.GridPoint != null)
{
cell = valueEvaluator.Visit(node.GridPoint);
}
else
{
cell = sender.GetCurrentCell();
}
// Evaluate expression or string
object result;
if (node.Value is ExpressionNode exprNode)
{
if (exprNode is ComparisonNode)
{
result = new ComparisonExpressionAstEvaluator().Visit(exprNode);
}
else
{
result = new MathExpressionAstEvaluator().Visit(exprNode);
}
}
else
{
result = ((StringValueNode)node.Value).Value;
}
// Retrieve state member for the next cell
Cell nextCell = sender.GetNextCell(cell.Pos);
MemberSymbol member = nextCell.State.RetrieveMember(node.MemberID.Label);
if (member != null)
{
try
{
// Set new value
switch (result)
{
case int i: member.SetValue(i); break;
case string s: member.SetValue(s); break;
default: throw new TheLanguageErrorException($"Cannot assign value of type \'{ result.GetType() }\' to a member");
}
}
catch (TheLanguageErrorException e)
{
throw new TheLanguageErrorException($"Member .{ member.Label }", e);
}
}
else
{
throw new TheLanguageErrorException($"Unknown member \'{ node.MemberID.Label }\'");
}
}
public override int Visit(InfixExpressionNode node)
{
MathExpressionAstEvaluator expressionAstEvaluator = new MathExpressionAstEvaluator();
return(expressionAstEvaluator.Visit(node));
}