go-pathmatch/internal_error.go

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package pathmatch
import (
"bytes"
"fmt"
)
const (
internalErrorMessagePrefix = "Internal Error: "
)
type InternalError interface {
error
InternalError()
}
// internalInternalError is the only underlying implementation that fits the
// InternalError interface, in this library.
type internalInternalError struct {
msg string
}
// newInternalError creates a new internalInternalError (struct) and
// returns it as a InternalError (interface).
func newInternalError(format string, a ...interface{}) InternalError {
msg := fmt.Sprintf(format, a...)
err := internalInternalError{
msg:msg,
}
return &err
}
// Error method is necessary to satisfy the 'error' interface (and the InternalError
// interface).
func (err *internalInternalError) Error() string {
var buffer bytes.Buffer
buffer.WriteString(internalErrorMessagePrefix)
buffer.WriteString(err.msg)
return buffer.String()
}
// InternalError method is necessary to satisfy the 'InternalError' interface.
// It exists to make this error type detectable in a Go type-switch.
func (err *internalInternalError) InternalError() {
// Nothing here.
}