// Package graph provides thin, reusable helpers over a dafsa Cursor that the move
// generator builds on. It keeps the rest of the solver from depending on dafsa
// traversal details directly.
package graph

import dawg "github.com/iliadenisov/dafsa"

// Spell follows the given alphabet indices from the cursor's root. It returns the
// state reached, whether that state is accepting, and whether the whole path exists.
// When ok is false the path ran into a missing edge; n and final are meaningless.
func Spell(c *dawg.Cursor, indices []byte) (n dawg.Node, final, ok bool) {
	n = c.Root()
	final = c.Final(n)
	for _, ix := range indices {
		n, final, ok = c.Next(n, ix)
		if !ok {
			return n, false, false
		}
	}
	return n, final, true
}