Unity Crashes when i attach script to object (554755)

So whenever i attach this script Unity stops responding
Im not sure if because of my script but here is my script anyways:

#pragma strict

public class weapon extends overWorld
{
public var ammo : int;
public var damage : int;
public var numberOfBullets : int;
public var firetype : int;
public var range :int;
public var weaponType : weaponTypes;

}

public function weapon()
{
ammo = 0;
damage = 0;
numberOfBullets = 0;
firetype = 0;
range = 0;
weaponType = weaponTypes.pistol;
}

public function weapon(amm : int, dmg : int, numOfBullets : int, rateOfFire : int, rng : int, wpnType : weaponTypes)
{
ammo = amm;
damage = dmg;
numberOfBullets = numOfBullets;
firetype = rateOfFire;
range = rng;
weaponType = wpnType;
}

public enum weaponTypes
{
sword,
pistol,
shotgun,
machinegun,
semiauto,
sniper,
}

public var sniper : weapon = new weapon(5, 5, 5, 1, 5, weaponTypes.sniper);

I believe the problem may be due to the enum varible

CODE TAGS!!