private AqlExpression VisitNewArrayInit(NewArrayExpression node)
{
// allow construction only of JsonValue[] arrays
// (as an argument to the JsonArray constructor)
if (node.Type.GetElementType() != typeof(JsonValue))
{
throw new AqlParsingException(
$"Expression {node} cannot be converted to AQL expression"
);
}
List <AqlExpression> args = node.Expressions.Select(Visit).ToList();
var result = new AqlJsonArrayExpression();
foreach (AqlExpression item in args)
{
result.Add(item);
}
return(result);
}
private AqlExpression VisitCall(MethodCallExpression node)
{
AqlExpression instance = Visit(node.Object);
List <AqlExpression> args = node.Arguments
.Select(Visit)
.ToList();
// === handle arango functions ===
ArangoFunctionAttribute attribute = node.Method
.GetCustomAttribute <ArangoFunctionAttribute>();
if (attribute != null)
{
return(new AqlFunctionExpression(attribute, args));
}
// === intercept indexing on JSON objects and arrays ===
if (possibleIndexerMethods.Contains(node.Method) &&
args.Count == 1)
{
return(new AqlMemberAccessExpression(
instance,
args[0]
));
}
// === handle JSON object construction ===
// if we call .Add on a JsonObject instance
if (node.Object?.Type == typeof(JsonObject) &&
node.Method.Name == "Add")
{
// start construction
if (instance is AqlConstantExpression constant)
{
instance = new AqlJsonObjectExpression(constant.Value);
}
// continue construction
if (instance is AqlJsonObjectExpression obj)
{
return(obj.CallAddViaArgs(args));
}
}
// === handle JSON array construction ===
// if we call .Add on a JsonArray instance
if (node.Object?.Type == typeof(JsonArray) &&
node.Method.Name == "Add")
{
// start construction
if (instance is AqlConstantExpression constant)
{
instance = new AqlJsonArrayExpression(constant.Value);
}
// continue construction
if (instance is AqlJsonArrayExpression arr)
{
return(arr.CallAddViaArgs(args));
}
}
// === expression is invalid ===
throw new AqlParsingException(
$"Expression uses parameters in method '{node.Method}'" +
", but this method cannot be translated to AQL"
);
}
