Custom Operators

Adding Custom Operators

Custom operators can be added with the useOperators(type, operatorMap) where type is the kind of operators to add, and operatorMap is mapping of function names beginning with $ to their implementations for the specific operator type.

Once an operator has been registered the function referenced cannot be replaced. This ensures that behaviour of mingo remain consistent at runtime.

Each operator type function has a different signature and must be registered correctly otherwise the result will be unexpected.

• AccumulatorOperator
• ExpressionOperator
• ProjectionOperator
• PipelineOperator
• WindowOperator
• QueryOperator

Pre-loaded operators defined here cannot be overridden. These include;

• All query operators.
• All projection operators.
• Expression operators for boolean and comparison.
• Pipeline operators; $project, $skip, $limit, and $sort.