public void Visit(MatchStatementNode node)
{
try
{
// Find the first caseStatement
CaseStatementNode caseNode = GetFirstMatchingCase(node);
// Visit the statement inside the matching caseStatement
if (caseNode != null)
{
Visit(caseNode.Statement);
}
}
catch (TheLanguageErrorException e) { throw new TheLanguageErrorException("Match statement", e); }
}
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);
}
