public void Visit(GridAssignmentStatementNode node)
{
ValueAstEvaluator valueVisitor = new ValueAstEvaluator(sender);
Cell c = valueVisitor.Visit(node.GridPoint);
// Extract result
Symbol state = Stbl.st.Retrieve(node.Identifier.Label);
if (state is StateSymbol s)
{
sender.SetCell(c, s);
}
else
{
throw new TheLanguageErrorException($"Grid assignment statement. Unexpected type for \'{ node.Identifier.Label }\' got { state } expected State");
}
}
private CaseStatementNode GetFirstMatchingCase(MatchStatementNode node)
{
ValueAstEvaluator valueVisitor = new ValueAstEvaluator(sender);
List <ValueNode> values = new List <ValueNode>();
// Evaluate elements
int i = 0;
foreach (var element in node.Elements)
{
switch (element)
{
case IdentifierValueNode t:
AddIdentifierElement(t, values);
break;
case IdentifierNode t:
AddIdentifierElement(new IdentifierValueNode(t.Label), values);
break;
case GridValueNode t:
Cell otherCell = valueVisitor.Visit(t);
values.Add(new StateValueNode(otherCell.State));
break;
case StringValueNode t:
values.Add(t);
break;
case IntValueNode t:
values.Add(t);
break;
case NumberNode t:
values.Add(new IntValueNode(t.Value));
break;
default:
throw new Exception($"Case matching has yet to be implemented for MatchElement: [{ i }] { element.GetType() }");
}
i++;
}
// Error handling from case matching
i = 1;
try
{
// Find first matching case
foreach (CaseStatementNode c in node.CaseStatementNodes)
{
if (IsCaseMatching(c, values))
{
return(c);
}
i++;
}
}
catch (TheLanguageErrorException e)
{
throw new TheLanguageErrorException($"Case statement { i }", e);
}
return(null);
}
public void Visit(MemberAssignmentStatementNode node)
{
ValueAstEvaluator valueEvaluator = new ValueAstEvaluator(sender);
Cell cell;
// Get cell
if (node.GridPoint != null)
{
cell = valueEvaluator.Visit(node.GridPoint);
}
else
{
cell = sender.GetCurrentCell();
}
// Evaluate expression or string
object result;
if (node.Value is ExpressionNode exprNode)
{
if (exprNode is ComparisonNode)
{
result = new ComparisonExpressionAstEvaluator().Visit(exprNode);
}
else
{
result = new MathExpressionAstEvaluator().Visit(exprNode);
}
}
else
{
result = ((StringValueNode)node.Value).Value;
}
// Retrieve state member for the next cell
Cell nextCell = sender.GetNextCell(cell.Pos);
MemberSymbol member = nextCell.State.RetrieveMember(node.MemberID.Label);
if (member != null)
{
try
{
// Set new value
switch (result)
{
case int i: member.SetValue(i); break;
case string s: member.SetValue(s); break;
default: throw new TheLanguageErrorException($"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 }\'");
}
}