use io;
use fmt;

export type invalid      = !(uint, uint);
export type unterminated = !(const str, uint, uint);
export type error        = !(invalid | unterminated | io::error);

export type quotstart = void;
export type quotend   = void;
export type mapstart  = void;
export type mapend    = void;

export type comment = struct { v: str };
export type word    = struct { v: str };
export type symbol  = struct { v: str, kw: bool };

export type token = (quotstart | quotend | mapstart | mapend |
	word | symbol | comment | str | rune | bool);

export fn strerror(err: error) const str = {
	static let buf: [64]u8 = [0...];
	match (err) {
	case let err: invalid =>
		return fmt::bsprintf(buf,
			"Invalid token found at {}:{}", err.0, err.1);
	case let err: unterminated =>
		return fmt::bsprintf(buf,
			"Unterminated {} found at {}:{}", err.0, err.1, err.2);
	case let err: io::error =>
		return io::strerror(err);
	};
};