Package errors implements various utility functions and types around errors.
ErrPreconditionViolated is returned when the precondition is violated
FilterOut removes all errors that match any of the matchers from the input error. If the input is a singular error, only that error is tested. If the input implements the Aggregate interface, the list of errors will be processed recursively.
This can be used, for example, to remove known-OK errors (such as io.EOF or os.PathNotFound) from a list of errors.
Reduce will return err or, if err is an Aggregate and only has one item, the first item in the aggregate.
Aggregate represents an object that contains multiple errors, but does not necessarily have singular semantic meaning. The aggregate can be used with `errors.Is()` to check for the occurrence of a specific error type. Errors.As() is not supported, because the caller presumably cares about a specific error of potentially multiple that match the given type.
AggregateGoroutines runs the provided functions in parallel, stuffing all non-nil errors into the returned Aggregate. Returns nil if all the functions complete successfully.
CreateAggregateFromMessageCountMap converts MessageCountMap Aggregate
Flatten takes an Aggregate, which may hold other Aggregates in arbitrary nesting, and flattens them all into a single Aggregate, recursively.
NewAggregate converts a slice of errors into an Aggregate interface, which is itself an implementation of the error interface. If the slice is empty, this returns nil. It will check if any of the element of input error list is nil, to avoid nil pointer panic when call Error().
Matcher is used to match errors. Returns true if the error matches.
MessageCountMap contains occurrence for each error message.