use encoding::utf8;
use io;

// Any error that may occur during parsing.
export type error = !(syntaxerr | io::error | utf8::invalid);

// All syntax errors defined in this module.
export type syntaxerr = !(
	invalid_group_header |
	invalid_entry |
	invalid_ascii |
	invalid_escape);

// Returned when a malformed group header is encountered while parsing.
export type invalid_group_header = !void;

// Returned when a malformed entry is encountered while parsing.
export type invalid_entry = !void;

// Returned when ASCII text was expected while parsing, but something else was
// given.
export type invalid_ascii = !void;

// Returned when an invalid escape sequence was enctountered while parsing.
export type invalid_escape = !void;

// Returns a user-friendly representation of [[error]]. The result may be
// statically allocated.
export fn strerror(err: error) str = match (err) {
case invalid_group_header   => yield "invalid group header";
case invalid_entry          => yield "invalid entry";
case invalid_ascii          => yield "invalid ascii";
case invalid_escape         => yield "invalid escape";
case let err: io::error     => yield io::strerror(err);
case let err: utf8::invalid => yield utf8::strerror(err);
};