A git_diff generated by one of the above functions.
A git_diff_format_t value to pick the text format.
Callback to make per line of diff text.
Reference pointer that will be passed to your callback.
0 on success, non-zero callback return value, or error code
Iterate over a diff generating formatted text output.
Returning a non-zero value from the callbacks will terminate the iteration and return the non-zero value to the caller.