package parser

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

// Item types that are produced by this parser.
const (
	ItemComment    parsekit.ItemType = iota // Comment string
	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
	validEscapeChars string = `btnfr"\`
	mustBeEscaped    string = "" +
		"\u0000\u0001\u0002\u0003\u0004\u0005\u0006\u0007" +
		"\u0008\u0009\u000A\u000B\u000C\u000D\u000E\u000F" +
		"\u0010\u0011\u0012\u0013\u0014\u0015\u0016\u0017" +
		"\u0018\u0019\u001A\u001B\u001C\u001D\u001E\u001F" +
		"\u007F"
)

var (
	keySeparatorDot = []interface{}{whitespace, dot, whitespace}
	doubleQuote3    = []interface{}{doubleQuote, doubleQuote, doubleQuote}
	hex4            = []interface{}{hex, hex, hex, hex}
	shortUtf8Match  = []interface{}{backslash, 'u', hex4}
	longUtf8Match   = []interface{}{backslash, 'U', hex4, hex4}
)

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