Role Playing Game

10 Points

options

Instructions

In this exercise, you'll be implementing mechanics of a role-playing game. A player's character is represented by the following type:

type Player = {
    Name: string option
    Level: int
    Health: int
    Mana: int option
}

Players in this game must reach level 10 before they unlock a mana pool so that they can start casting spells. You'll be working on two pieces of functionality in this game: the revive mechanic and the spell casting mechanic.

1. Introduce yourself

Write the content of the introduce function. Note that the Name field of the Player record is an Option. Stealthy players might want to hide their name by leaving it set to None -- such players will be introduced as "Mighty Magician". Otherwise, just use your name to introduce yourself.

introduce { Name = None; Level = 2; Health = 8; Mana = None }
    --> "Mighty Magician"

introduce { Name = Some "Merlin"; Level = 2; Health = 8; Mana = None }
    --> "Merlin"

2. Implement the revive mechanic

The revive function should check that the player's character is indeed dead (their health has reached 0). If they are, it should return a new Player instance with 100 health. Otherwise, if the player's character isn't dead, the revive function returns None.

If the player's level is 10 or above, they should also be revived with 100 mana. If the player's level is below 10, their mana should be None. The revive function should preserve the player's level.

let deadPlayer = { Name = None; Level = 2; Health = 0; Mana = None }

revive deadPlayer
    --> Some { Name = None; Level = 2; Health = 100; Mana = None }

If the revive method is called on a player whose health is 1 or above, then the function should return None.

let alivePlayer = { Name = None; Level = 2; Health = 42; Mana = None }

revive alivePlayer
    --> None

3. Implement the spell casting mechanic

The castSpell function takes as arguments an int indicating how much mana the spell costs as well as a Player. It returns the updated player, as well as the amount of damage that the cast spell inflicts. A successful spell cast does damage equal to two times the mana cost of the spell. However, if the player has insufficient mana, nothing happens, the player is unchanged and no damage is done. If the player does not even have a mana pool, attempting to cast the spell must decrease their health by the mana cost of the spell and does no damage.

let wizard = { Name = None; Level = 18; Health = 123; Mana = Some 30 }

let updatedWizard, damage = castSpell 14 wizard

updatedWizard.Mana --> Some 16
damage             --> 28

fsharp