public ThenNode Then(string value)
{
ThenNode thenNode = new ThenNode();
Match(TokenType.THEN);
return(thenNode);
}
public override void Visit(ThenNode node)
{
if (node.Descendants.Length == 0)
{
ReportLackOfThenExpression(node);
}
}
private WhenThenNode[] ComposeWhenThenNodes()
{
var nodes = new List <WhenThenNode>();
while (!IsElseNode(Current))
{
WhenNode when = null;
ThenNode then = null;
switch (Current.TokenType)
{
case StatementType.When:
when = new WhenNode(ConsumeAndGetToken(), ComposeWhere());
goto case StatementType.Then;
case StatementType.Then:
then = new ThenNode(ConsumeAndGetToken(), ComposeWhere());
break;
default:
throw new NotSupportedException();
}
if (when == null || then == null)
{
throw new NullReferenceException();
}
nodes.Add(new WhenThenNode(when, then));
}
return(nodes.ToArray());
}
/// <summary>
/// Visit Then node in DFS manner.
/// </summary>
/// <param name="node">Then node that will be visited.</param>
public void Visit(ThenNode node)
{
while (_contextChangeTracker.Count > 0)
{
_contextChangeTracker.Pop();
_scope = _scope.OuterScope;
}
_scope = new ScopeContext(_scope, _functionScopeTable, "then");
}
/// <summary>
/// Performs "Then" specific operations.
/// </summary>
/// <param name="node">The "Numeric" node.</param>
public virtual void Visit(ThenNode node)
{
var elseSpan = node.Parent.Parent.Else.FullSpan;
Instructions.Add(new JumpToLabel($"esac_{elseSpan.Start}{elseSpan.End}"));
if (node.Parent.ArrayOrder == node.Parent.Parent.WhenThenExpressions.Length - 1)
{
_labels.Add($"else_{node.Parent.Parent.Else.FullSpan.Start}{node.Parent.Parent.Else.FullSpan.End}",
Instructions.Count);
}
}
public KeyValuePair <object, Continue> Eval(Env e, Continue k)
{
return(PredNode.Eval(e, b => {
if ((bool)b)
{
return ThenNode.Eval(e, k);
}
else
{
return ElseNode.Eval(e, k);
}
}));
}
/// <summary>
/// Visit Then node in DFS manner.
/// </summary>
/// <param name="node">Then node that will be visited.</param>
public virtual void Visit(ThenNode node)
{
node.Descendant.Accept(this);
node.Accept(_visitor);
}
private void ReportLackOfThenExpression(ThenNode node)
{
AddSyntaxError(node.FullSpan, string.Format(AnalysisMessage.LackOfThenReturnExpression, node),
SyntaxErrorKind.LackOfExpression);
}
public override void Visit(ThenNode node) => ProduceDebuggerInstructions(node, n => base.Visit(n));
/// <summary> /// Visit Then node. /// </summary> /// <param name="node">Then node of AST</param> public abstract void Visit(ThenNode node);
/// <summary>
/// Visit Then node in BFS manner.
/// </summary>
/// <param name="node">Then node that will be visited.</param>
public override void Visit(ThenNode node)
{
node.Accept(Visitor);
node.Descendant.Accept(this);
_contextChangeTracker.Push(true);
}
