internal void ResolveValue(IJsonPlusNode child)
{
if (child.Type == JsonPlusType.Empty)
{
Remove(child);
}
else if (Type == JsonPlusType.Empty)
{
Type = child.Type;
}
else if (Type != child.Type)
{
JsonPlusSubstitution sub = (JsonPlusSubstitution)child;
throw JsonPlusParserException.Create(sub, sub.Path, string.Format(RS.SubstitutionSiblingTypeMismatch, Type, child.Type));
}
if (Parent is JsonPlusArray)
{
// #todo
((JsonPlusArray)Parent).ResolveValue(this);
return;
}
((JsonPlusObjectMember)Parent).ResolveValue(this);
}
private JsonPlusValue ResolveSubstitution(JsonPlusSubstitution sub)
{
JsonPlusObjectMember subField = sub.ParentMember;
// first case, this substitution is a direct self-reference
if (sub.Path == sub.GetMemberPath())
{
IJsonPlusNode parent = sub.Parent;
while (parent is JsonPlusValue)
{
parent = parent.Parent;
}
// Fail case
if (parent is JsonPlusArray)
{
throw new JsonPlusException(RS.SelfRefSubstitutionInArray);
}
// try to resolve substitution by looking backward in the field assignment stack
return(subField.OlderValueThan(sub));
}
// need to recursively get full path
JsonPlusPath fieldPath = subField.GetMemberPath();
// second case, the substitution references a field child in the past
if (sub.Path.IsChildPathOf(fieldPath))
{
JsonPlusValue olderValue = subField.OlderValueThan(sub);
if ((olderValue != null) &&
(olderValue.Type == JsonPlusType.Object))
{
int difLength = sub.Path.Count - fieldPath.Count;
JsonPlusPath deltaPath = sub.Path.SubPath(sub.Path.Count - difLength, difLength);
JsonPlusObject olderObject = olderValue.GetObject();
if (olderObject.TryGetValue(deltaPath, out JsonPlusValue innerValue))
{
return(innerValue.Type == JsonPlusType.Object ? innerValue : null);
}
}
}
// Detect invalid parent-referencing substitution
if (fieldPath.IsChildPathOf(sub.Path))
{
throw new JsonPlusException(RS.SubstitutionRefDirectParentError);
}
// Detect invalid cyclic reference loop
if (IsValueCyclic(subField, sub))
{
throw new JsonPlusException(RS.CyclicSubstitutionLoop);
}
// third case, regular substitution
_root.GetObject().TryGetValue(sub.Path, out JsonPlusValue field);
return(field);
}
internal void ResolveValue(JsonPlusSubstitution sub)
{
if (sub.Type == JsonPlusType.Empty)
{
Remove(sub);
return;
}
}
private IJsonPlusNode ParseSelfAssignArray(IJsonPlusNode owner)
{
// sanity check
if (_tokens.Current.Type != TokenType.SelfAssignment)
{
throw JsonPlusParserException.Create(_tokens.Current, Path, string.Format(RS.UnexpectedTokenInArray, TokenType.SelfAssignment, _tokens.Current.Type));
}
// consume += operator token
ConsumeWhitelines();
JsonPlusArray currentArray = new JsonPlusArray(owner);
switch (_tokens.Current.Type)
{
case TokenType.Include:
case TokenType.OptionalInclude:
// #todo
currentArray.Add(ParseInclude(currentArray));
break;
case TokenType.StartOfArray:
return(ParseArray(owner));
case TokenType.StartOfObject:
// #todo
currentArray.Add(ParseObject(currentArray));
break;
case TokenType.LiteralValue:
if (_tokens.Current.IsNonSignificant())
{
ConsumeWhitelines();
}
if (_tokens.Current.Type != TokenType.LiteralValue)
{
break;
}
currentArray.Add(ParseValue(currentArray));
return(currentArray);
case TokenType.OptionalSubstitution:
case TokenType.Substitution:
JsonPlusPath pointerPath = JsonPlusPath.Parse(_tokens.Current.Value);
JsonPlusSubstitution sub = new JsonPlusSubstitution(owner, pointerPath, _tokens.Current,
_tokens.Current.Type == TokenType.Substitution);
_substitutions.Add(sub);
_tokens.Next();
return(sub);
default:
throw JsonPlusParserException.Create(_tokens.Current, Path, string.Format(RS.UnexpectedTokenInArray, TokenType.EndOfArray, _tokens.Current.Type));
}
return(currentArray);
}
/// <summary>
/// Retrieves the next value token from the tokenizer and appends it
/// to the supplied element <paramref name="owner"/>.
/// </summary>
/// <param name="owner">The element to append the next token.</param>
/// <exception cref="Exception">End of file reached while trying to read a value</exception>
private JsonPlusValue ParseValue(IJsonPlusNode owner)
{
JsonPlusValue value = new JsonPlusValue(owner);
bool parsing = true;
while (parsing)
{
switch (_tokens.Current.Type)
{
case TokenType.Include:
case TokenType.OptionalInclude:
value.Add(ParseInclude(value));
break;
case TokenType.LiteralValue:
// Consume leading whitespaces.
if (_tokens.Current.IsNonSignificant())
{
ConsumeWhitespace();
}
if (_tokens.Current.Type != TokenType.LiteralValue)
{
break;
}
while (_tokens.Current.Type == TokenType.LiteralValue)
{
value.Add(JsonPlusLiteralValue.Create(value, _tokens.Current));
_tokens.Next();
}
break;
case TokenType.StartOfObject:
value.Add(ParseObject(value));
break;
case TokenType.StartOfArray:
value.Add(ParseArray(value));
break;
case TokenType.OptionalSubstitution:
case TokenType.Substitution:
JsonPlusPath pointerPath = JsonPlusPath.Parse(_tokens.Current.Value);
JsonPlusSubstitution sub = new JsonPlusSubstitution(value, pointerPath, _tokens.Current,
_tokens.Current.Type == TokenType.Substitution);
_substitutions.Add(sub);
value.Add(sub);
_tokens.Next();
break;
case TokenType.EndOfObject:
case TokenType.EndOfArray:
parsing = false;
break;
// comments automatically stop value parsing.
case TokenType.Comment:
ConsumeWhitelines();
parsing = false;
break;
case TokenType.EndOfLine:
parsing = false;
break;
case TokenType.EndOfFile:
case TokenType.ArraySeparator:
parsing = false;
break;
case TokenType.SelfAssignment:
JsonPlusSubstitution subAssign = new JsonPlusSubstitution(value, new JsonPlusPath(Path), _tokens.Current, false);
_substitutions.Add(subAssign);
value.Add(subAssign);
value.Add(ParseSelfAssignArray(value));
parsing = false;
break;
case TokenType.Assignment:
ConsumeWhitelines();
break;
default:
throw JsonPlusParserException.Create(_tokens.Current, Path, string.Format(RS.ErrAtUnexpectedToken, _tokens.Current.Type));
}
}
// trim trailing whitespace if result is a literal
if (value.Type == JsonPlusType.Literal)
{
if (value[value.Count - 1] is WhitespaceValue)
{
value.RemoveAt(value.Count - 1);
}
}
return(value);
}
private bool IsValueCyclic(JsonPlusObjectMember field, JsonPlusSubstitution sub)
{
Stack <JsonPlusValue> pendingValues = new Stack <JsonPlusValue>();
List <JsonPlusObjectMember> visitedFields = new List <JsonPlusObjectMember> {
field
};
Stack <JsonPlusSubstitution> pendingSubs = new Stack <JsonPlusSubstitution>();
pendingSubs.Push(sub);
while (pendingSubs.Count > 0)
{
JsonPlusSubstitution currentSub = pendingSubs.Pop();
if (!_root.GetObject().TryGetMember(currentSub.Path, out var currentField))
{
continue;
}
if (visitedFields.Contains(currentField))
{
return(true);
}
visitedFields.Add(currentField);
pendingValues.Push(currentField.Value);
while (pendingValues.Count > 0)
{
JsonPlusValue currentValue = pendingValues.Pop();
foreach (IJsonPlusNode value in currentValue)
{
switch (value)
{
case JsonPlusLiteralValue _:
break;
case JsonPlusObject o:
foreach (JsonPlusObjectMember f in o.Values)
{
if (visitedFields.Contains(f))
{
return(true);
}
visitedFields.Add(f);
pendingValues.Push(f.Value);
}
break;
case JsonPlusArray a:
foreach (JsonPlusValue item in a.GetArray())
{
pendingValues.Push(item);
}
break;
case JsonPlusSubstitution s:
pendingSubs.Push(s);
break;
}
}
}
}
return(false);
}
