package plugin
 
 import "fmt"
 
 type errNotFound string
 
 func (name errNotFound) Error() string {
 	return fmt.Sprintf("plugin %q not found", string(name))
 }
 
 func (errNotFound) NotFound() {}
 
 type errAmbiguous string
 
 func (name errAmbiguous) Error() string {
 	return fmt.Sprintf("multiple plugins found for %q", string(name))
 }
 
 func (name errAmbiguous) InvalidParameter() {}
 
 type errDisabled string
 
 func (name errDisabled) Error() string {
 	return fmt.Sprintf("plugin %s found but disabled", string(name))
 }
 
 func (name errDisabled) Conflict() {}
 
 type invalidFilter struct {
 	filter string
 	value  []string
 }
 
 func (e invalidFilter) Error() string {
 	msg := "Invalid filter '" + e.filter
 	if len(e.value) > 0 {
 		msg += fmt.Sprintf("=%s", e.value)
 	}
 	return msg + "'"
 }
 
 func (invalidFilter) InvalidParameter() {}
 
 type inUseError string
 
 func (e inUseError) Error() string {
 	return "plugin " + string(e) + " is in use"
 }
 
 func (inUseError) Conflict() {}
 
 type enabledError string
 
 func (e enabledError) Error() string {
 	return "plugin " + string(e) + " is enabled"
 }
 
 func (enabledError) Conflict() {}
 
 type alreadyExistsError string
 
 func (e alreadyExistsError) Error() string {
 	return "plugin " + string(e) + " already exists"
 }
 
 func (alreadyExistsError) Conflict() {}