In the King of Tars, the princess dreams of one hundred black hounds who threaten her, but she thinks of God and is unharmed. It is easily apparent that the swarm of wild dogs is the Saracen army that invaded her father's kingdom - their dark coats representing the darker skin of the men in the Sultan's ranks. Then she dreams of another hound, singular this time (likely the Sultan himself) who is at first threatening to her, until she meditates on the passion of Christ. At her display of faith the hound transforms into a white knight. This mirrors the Sultan's own transformation after God reshapes his deformed child and he agrees to convert.
But aside from the bazaar change in the pigment of her husband's skin, the princess dreams of the world as it was and will be in the surrealists tones that speak to a deeper level of understanding. This kind of subconscious storytelling pervades through the modern narrative, not only touching books but films, music and video games as well. For the more visually based narrative dreams play a crucial factor in our understanding of the internal workings of a character. Taking for instance the dream sequence in Ridley Scott's Blade Runner where Harrison Ford chases a unicorn through the woods. Despite the film's complex surrealism, it is understood that the flight of the unicorn is representative of Ford's own goals.
Another example from an even more resent film can be found in Scott Pilgrim vs. The World, where Scott is a down on his luck boy wishing for a girlfriend. In his dream he is stranded in the middle of an expansive desert with no one around. When he lays down to die, a girl that he hadn't yet met skates through the dust and past him again. This girl would come into the film in the following scene.