errmap

This package focuses on extending Go 1.13's new error framework to make it easier to inject wrappers throughout the error handling process.

Packages

errmap

This package provides functions MapFirst, MapBefore, MapAfter, and MapLast that allow a chain of error mappers to be constructed for a single error. This makes it easier to control the ordering of error modifications.

For example, it is often desirable to first apply operations that significantly alter an error (e.g., replacing an internal error with a different kind of error), then perform non-mutating operations that gather information from the error, and finally to apply convenient formatting for end-user consumption.

errmark

This package provides an errmap-compatible wrapper that allows errors to be classified into semantic groups. By marking an error, it can be inspected later to see if it fits into one or more of these groups and handled as needed.