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package o1game.Model
/** The class `Action` represents actions that a player may take in a text adventure game.
* `Action` objects are constructed on the basis of textual commands and are, in effect,
* parsers for such commands. An action object is immutable after creation.
* @param input a textual in-game command such as “go east” or “rest” */
class Action(input: String):
private val commandText = input.trim.toLowerCase
private val verb = commandText.takeWhile( _ != ' ' )
private val modifiers = commandText.drop(verb.length).trim
/** Causes the given player to take the action represented by this object, assuming
* that the command was understood. Returns a description of what happened as a result
* of the action (such as “You go west.”). The description is returned in an `Option`
* wrapper; if the command was not recognized, `None` is returned. */
def execute(actor: Entity): Option[String] =
this.verb match
case "go" => Some(actor.go(this.modifiers))
case "rest" => Some(actor.rest())
case "get" => Some(actor.pickUp(this.modifiers))
case "drop" => Some(actor.drop(this.modifiers))
case "xyzzy" => Some("The grue tastes yummy.")
case "quit" => Some(actor.quit())
case other => None
/** Returns a textual description of the action object, for debugging purposes. */
override def toString = s"$verb (modifiers: $modifiers)"
end Action
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