public override DynValue Visit(IndexingNode indexingNode)
{
var indexable = Visit(indexingNode.Indexable);
var keyValue = Visit(indexingNode.KeyExpression);
return(IndexDynValue(indexable, keyValue, indexingNode));
}
private DynValue IndexDynValue(DynValue indexable, DynValue keyValue, IndexingNode indexingNode)
{
switch (indexable.Type)
{
case DynValueType.String:
{
if (keyValue.Type != DynValueType.Number)
{
throw new RuntimeException($"Attempt to index a string using {keyValue.Type}.",
indexingNode.Line);
}
var index = (int)keyValue.Number;
if (index < 0)
{
if (indexable.String.Length + index < 0)
{
throw new RuntimeException("String index out of bounds.", indexingNode.Line);
}
return(new DynValue(
indexable.String[^ (-index)]
public abstract DynValue Visit(IndexingNode indexingNode);
