/// <summary>
/// Deserializes a Bonsai expression.
/// </summary>
/// <param name="expression">Bonsai expression to deserialize.</param>
/// <returns>Slim expression represented by the given Bonsai.</returns>
public ExpressionSlim Deserialize(Json.Expression expression)
{
if (expression == null)
{
throw new ArgumentNullException(nameof(expression));
}
Json.Expression expr;
if (_mergeContext && _deserializationState != null)
{
expr = expression;
}
else
{
if (expression.NodeType == Json.ExpressionType.Null)
{
return(null);
}
if (expression is not Json.ObjectExpression obj)
{
throw new BonsaiParseException("Expected a JSON object containing the Bonsai representation of an expression.", expression);
}
if (!obj.Members.TryGetValue("Context", out Json.Expression context))
{
throw new BonsaiParseException("Expected a JSON object property 'node.Context' containing the context object.", expression);
}
if (!obj.Members.TryGetValue("Expression", out expr))
{
throw new BonsaiParseException("Expected a JSON object property 'node.Expression' containing the expression tree.", expression);
}
_deserializationState = new DeserializationState(context, _version);
}
if (expr.NodeType == Json.ExpressionType.Null)
{
return(null);
}
var visitor = new DeserializerImpl(_deserializationState, _reduceFactory);
return(visitor.Visit(expr));
}
public DeserializerImpl(DeserializationState state, Func <Type, Func <Json.Expression, object> > reduceFactory)
: base(state)
{
_reduceFactory = reduceFactory;
}
