Iterator for depth first search of a tree node

dfs-iterator.js

const dfsIterator = node => {
  const nodes = [ node ]

  const next = () => {
    const done = nodes.length === 0

    if( done ) return { done }

    const value = nodes.pop()
    let child = value.lastChild

    while( child ){
      nodes.push( child )
      child = child.previousSibling
    }

    return { done, value }
  }

  return {
    [Symbol.iterator]: () => ({ next })
  }
}

for( current of dfsIterator( node ) )
  console.log( current )

const arr = Array.from( dfsIterator( node ) )

const find = ( node, predicate ) => {
  for( current of dfsIterator( node ) )
    if( predicate( current ) ) return current
}

dfs-generator.js