package lexer

import "fmt"

// itemType represents the type of lexer items.
type itemType int

// Definition of all the lexer item types for the TOML lexer.
const (
	ItemError      itemType = iota // An error occurred
	ItemEOF                        // End of input reached
	ItemComment                    // Comment string, starts with # till en of line
	ItemKey                        // Key of a key/value pair
	ItemKeyDot                     // Dot for a dotted key
	ItemAssignment                 // Value assignment coming up (=)
	ItemString                     // A value of type string
)

// Item represents a lexer item returned from the scanner.
type Item struct {
	Type  itemType //Type, e.g. ItemComment, ItemString
	Value string   // Value, e.g. "10.42", "["
}

// String returns a string representation of the lexer item.
func (i Item) String() string {
	switch i.Type {
	case ItemEOF:
		return "EOF"
	case ItemKey:
		return fmt.Sprintf("[%s]", i.Value)
	case ItemKeyDot:
		return "."
	case ItemAssignment:
		return "="
	}
	return fmt.Sprintf("%s(%s)", i.Type, i.Value)
}

// String returns a string representation of the lexer item type.
func (i itemType) String() string {
	switch i {
	case ItemError:
		return "ERR"
	case ItemComment:
		return "#"
	case ItemString:
		return "STR"
	default:
		panic(fmt.Sprintf("No translation available for type id %d", i))
	}
}