package lexer

import "github.com/mmakaay/toml/parser"

// Item types that are emitted by this parser.
const (
	ItemComment    parser.ItemType = iota // An error occurred
	ItemKey                               // Key of a key/value pair
	ItemKeyDot                            // Dot for a dotted key
	ItemAssignment                        // Value assignment coming up (=)
	ItemString                            // A value of type string
)

const (
	whitespace      string = " \t"
	carriageReturn  string = "\r"
	newline         string = "\n"
	hash            string = "#"
	equal           string = "="
	lower           string = "abcdefghijklmnopqrstuvwxyz"
	upper           string = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	digits          string = "0123456789"
	hex             string = digits + "abcdefABCDEF"
	dot             string = "."
	underscore      string = "_"
	dash            string = "-"
	singleQuote     string = "'"
	doubleQuote     string = "\""
	backslash       string = "\\"
	quoteChars      string = singleQuote + doubleQuote
	bareKeyChars    string = lower + upper + digits + underscore + dash
	startOfKey      string = bareKeyChars + quoteChars
	escapeChars     string = `btnfr"\`
	shortUtf8Escape string = "u"
	longUtf8Escape  string = "U"
)

var (
	doubleQuote3   = []string{doubleQuote, doubleQuote, doubleQuote}
	shortUtf8Match = []string{backslash, "u", hex, hex, hex, hex}
	longUtf8Match  = []string{backslash, "U", hex, hex, hex, hex, hex, hex, hex, hex}
)

// NewParser creates a new parser, using the provided input string
// as the data to parse.
func NewParser(input string) *parser.Parser {
	return parser.New(input, stateKeyValuePair)
}