RCRPG/Go

From Rosetta Code
RCRPG/Go is part of RCRPG. You may find other members of RCRPG at Category:RCRPG.
package main
 
import (
"fmt"
"io"
"math/rand"
"os"
"sort"
"strings"
)
 
const (
VERSION_MAJOR = 1
VERSION_MINOR = 0
)
 
type Direction int
 
const (
NORTH = Direction(iota)
SOUTH
EAST
WEST
UP
DOWN
NUM_DIRECTIONS = iota
)
 
func (d Direction) Opposite() Direction {
return d ^ 1
}
 
func (d Direction) String() string {
switch d {
case NORTH:
return "north"
case SOUTH:
return "south"
case EAST:
return "east"
case WEST:
return "west"
case UP:
return "up"
case DOWN:
return "down"
}
panic("Invalid direction!")
}
 
type Item int
 
const (
NIL_ITEM = Item(iota)
GOLD
LADDER
SLEDGE
NUM_ITEMS = iota
)
 
func (item Item) String() string {
switch item {
case GOLD:
return "Gold coin"
case LADDER:
return "Ladder"
case SLEDGE:
return "Sledge hammer"
}
panic("Invalid item!")
}
 
type Room struct {
X, Y, Z int
Name string
Passages [6]*Room
Items map[Item]int
}
 
// Creates a new room
func GenerateRoom(X, Y, Z int) *Room {
room := new(Room)
room.X, room.Y, room.Z = X, Y, Z
room.Name = ""
room.Items = make(map[Item]int)
switch item := Item(rand.Intn(4)); item {
case GOLD, LADDER, SLEDGE:
room.Items[item]++
}
return room
}
 
// Connects this room to another
func (room *Room) Connect(dir Direction, other *Room) {
room.Passages[dir] = other
other.Passages[dir.Opposite()] = room
}
 
// The room name
func (room *Room) String() string {
if len(room.Name) == 0 {
return fmt.Sprintf("Room %d,%d,%d", room.X, room.Y, room.Z)
}
return room.Name
}
 
// Counts the number of items are laying in this room
func (room *Room) NumItems() int {
total := 0
for _, count := range room.Items {
total += count
}
return total
}
 
// Counts the number of exits out of this room
func (room *Room) NumExits() int {
total := 0
for _, other := range room.Passages {
if other != nil {
total++
}
}
return total
}
 
// Prints a description of the current room
func (room *Room) Describe() {
fmt.Printf("You are at %s\n", room)
if room.NumItems() > 0 {
fmt.Print("On the ground you can see: ")
first := true
for item := NIL_ITEM; item < NUM_ITEMS; item++ {
count := room.Items[item]
if count <= 0 {
continue
}
if !first {
fmt.Print(", ")
}
first = false
if count == 1 {
fmt.Printf("a %s", item)
} else {
fmt.Printf("%d %ss", count, item)
}
}
fmt.Println()
}
if room.NumExits() == 0 {
fmt.Print("There are no exits.\n")
} else {
fmt.Print("Exits are:\n")
for dir := Direction(0); dir < NUM_DIRECTIONS; dir++ {
other := room.Passages[dir]
if other != nil {
fmt.Printf("  %s: %s\n", dir, other)
}
}
}
}
 
type Game struct {
// Three level mapping of the rooms
Rooms map[int]map[int]map[int]*Room
// Number of items of each type
Inventory map[Item]int
// Currently equipped item
Equipped Item
// Current room
Room *Room
// All commands
Commands map[string]func(args []string)
// All aliases
Aliases map[string][]string
// Help texts
HelpText map[string]string
}
 
// Counts the number of items you have in your inventory
func (g *Game) NumItems() int {
total := 0
for _, count := range g.Inventory {
total += count
}
return total
}
 
// Creates or returns the room at specified coordinates.
func (g *Game) GetRoomAt(X, Y, Z int) *Room {
if g.Rooms == nil {
g.Rooms = make(map[int]map[int]map[int]*Room)
}
if g.Rooms[X] == nil {
g.Rooms[X] = make(map[int]map[int]*Room)
}
if g.Rooms[X][Y] == nil {
g.Rooms[X][Y] = make(map[int]*Room)
}
room := g.Rooms[X][Y][Z]
if room == nil {
room = GenerateRoom(X, Y, Z)
g.Rooms[X][Y][Z] = room
}
return room
}
 
// north, south, east, west, up, down: Moves around
func (g *Game) Move(args []string) {
if len(args) != 1 {
fmt.Print("Invalid number of arguments\n")
return
}
var dir Direction
switch strings.ToLower(args[0]) {
default:
fmt.Printf("Invalid direction: %q\n", args[0])
return
case "north":
dir = NORTH
case "south":
dir = SOUTH
case "east":
dir = EAST
case "west":
dir = WEST
case "up":
dir = UP
case "down":
dir = DOWN
}
other := g.Room.Passages[dir]
if other == nil {
fmt.Printf("You can't move %s. There is a wall in the way.\n", dir)
} else if dir == UP && g.Room.Items[LADDER] == 0 {
fmt.Printf("You can't move %s. There are no %s.\n", dir, LADDER)
} else {
g.Room = other
other.Describe()
}
}
 
// attack: Breaks a wall.
func (g *Game) Sledge(args []string) {
if len(args) != 1 {
fmt.Print("Invalid number of arguments\n")
return
}
if g.Equipped != SLEDGE {
fmt.Printf("You need a %s equipped to break the wall.\n", SLEDGE)
return
}
X, Y, Z := g.Room.X, g.Room.Y, g.Room.Z
var dir Direction
switch strings.ToLower(args[0]) {
default:
fmt.Printf("Invalid direction: %q\n", args[0])
return
case "north":
dir = NORTH
Y--
case "south":
dir = SOUTH
Y++
case "east":
dir = EAST
X++
case "west":
dir = WEST
X--
case "up":
dir = UP
Z++
case "down":
dir = DOWN
Z--
}
other := g.Room.Passages[dir]
if other != nil {
fmt.Print("There is already a passage there.\n")
return
}
other = g.GetRoomAt(X, Y, Z)
g.Room.Connect(dir, other)
fmt.Printf("Made a passage %s to %s\n", dir, other)
}
 
// drop: Puts items down
func (g *Game) DropItem(args []string) {
if len(args) != 1 {
fmt.Print("Invalid number of arguments\n")
return
}
var item Item
switch strings.ToLower(args[0]) {
default:
fmt.Printf("You don't have any %q.\n", args[0])
return
case "all":
if g.NumItems() == 0 {
fmt.Print("You don't have any items.\n")
return
}
fmt.Print("You drop: ")
first := true
for item := NIL_ITEM; item < NUM_ITEMS; item++ {
count := g.Inventory[item]
if count <= 0 {
continue
}
if !first {
fmt.Print(", ")
}
first = false
if count == 1 {
fmt.Printf("a %s", item)
} else {
fmt.Printf("%d %ss", count, item)
}
g.Inventory[item] = 0
g.Room.Items[item] += count
}
fmt.Println()
return
case "gold":
item = GOLD
case "ladder":
item = LADDER
case "sledge":
item = SLEDGE
}
total := g.Inventory[item]
if total == 0 {
fmt.Printf("You don't have any %ss.\n", item)
return
}
g.Inventory[item]--
g.Room.Items[item]++
fmt.Printf("You drop a %s.\n", item)
}
 
// take: Picks up items
func (g *Game) TakeItem(args []string) {
if len(args) != 1 {
fmt.Print("Invalid number of arguments\n")
return
}
var item Item
switch strings.ToLower(args[0]) {
default:
fmt.Printf("You don't see any %q.\n", args[0])
return
case "all":
if g.Room.NumItems() == 0 {
fmt.Print("You don't see any items.\n")
return
}
fmt.Print("You take: ")
first := true
for item := NIL_ITEM; item < NUM_ITEMS; item++ {
count := g.Room.Items[item]
if count <= 0 {
continue
}
if !first {
fmt.Print(", ")
}
first = false
if count == 1 {
fmt.Printf("a %s", item)
} else {
fmt.Printf("%d %ss", count, item)
}
g.Room.Items[item] = 0
g.Inventory[item] += count
}
fmt.Println()
return
case "gold":
item = GOLD
case "ladder":
item = LADDER
case "sledge":
item = SLEDGE
}
total := g.Room.Items[item]
if total == 0 {
fmt.Printf("You don't see any %ss.\n", item)
return
}
g.Room.Items[item]--
g.Inventory[item]++
fmt.Printf("You take a %s.\n", item)
}
 
// inventory: Shows what you are carrying
func (g *Game) ShowInventory(args []string) {
if len(args) != 0 {
fmt.Print("Invalid number of arguments\n")
return
}
if g.Equipped != NIL_ITEM {
fmt.Printf("You have a %s equipped.\n", g.Equipped)
}
if g.NumItems() == 0 {
fmt.Print("You are not carrying anything.\n")
return
}
fmt.Print("You are carrying: ")
first := true
for item := NIL_ITEM; item < NUM_ITEMS; item++ {
count := g.Inventory[item]
if count <= 0 {
continue
}
if !first {
fmt.Print(", ")
}
first = false
if count == 1 {
fmt.Printf("a %s", item)
} else {
fmt.Printf("%d %ss", count, item)
}
}
fmt.Println()
}
 
// name: Renames the current room
func (g *Game) RenameRoom(args []string) {
if len(args) != 1 {
fmt.Print("Invalid number of arguments\n")
return
}
g.Room.Name = args[0]
fmt.Printf("This room is now called %q\n", args[0])
g.Room.Describe()
}
 
// equip: Equips an item
func (g *Game) EquipItem(args []string) {
if len(args) != 1 {
fmt.Print("Invalid number of arguments\n")
return
}
var item Item
switch strings.ToLower(args[0]) {
default:
fmt.Printf("You don't have any %q.\n", args[0])
return
case "gold":
item = GOLD
case "ladder":
item = LADDER
case "sledge":
item = SLEDGE
}
count := g.Inventory[item]
if count <= 0 {
fmt.Printf("You don't have any %ss.\n", item)
return
} else if item == g.Equipped {
fmt.Printf("You already have a %s equipped.\n", item)
return
}
if g.Equipped != NIL_ITEM {
fmt.Printf("You unequip the %s. ", g.Equipped)
g.Inventory[g.Equipped]++
}
fmt.Printf("You equip a %s.\n", item)
g.Inventory[item]--
g.Equipped = item
}
 
// alias: Creats an alias
func (g *Game) CreateAlias(args []string) {
if len(args) < 1 {
fmt.Print("Invalid number of arguments\n")
return
}
name := strings.ToLower(args[0])
switch name {
case "north", "south", "east", "west", "up", "down", "attack",
"drop", "take", "inventory", "name", "equip", "alias":
fmt.Printf("Can't overwrite the %q command.\n", name)
return
}
if len(args) == 1 {
g.Commands[name] = nil
fmt.Printf("Removed the %q alias.\n", name)
return
}
g.Aliases[name] = args[1:]
fmt.Printf("Created the %q alias.\n", name)
}
 
// help: Shows information about commands
func (g *Game) Help(args []string) {
if len(args) == 0 {
fmt.Print("Commands:\n")
for _, cmd := range g.GetCommands() {
fmt.Printf("  %s\n", cmd)
}
} else if len(args) == 1 {
name := args[0]
arr, ok := g.Aliases[name]
if ok {
fmt.Printf("Alias for: %q\n", strings.Join(arr, " "))
return
}
_, ok = g.Commands[name]
if ok {
fmt.Printf("Command: %s\n", name)
descr, ok := g.HelpText[name]
if ok {
fmt.Printf("  %s\n", descr)
}
return
}
fmt.Printf("Unknown command: %q\n", name)
} else if len(args) > 1 {
fmt.Print("Invalid number of arguments\n")
}
}
 
// look: Looks around
func (g *Game) Look(args []string) {
if len(args) != 0 {
fmt.Print("Invalid number of arguments\n")
return
}
g.Room.Describe()
}
 
// quit: Ends the game. The End. Final.
func (g *Game) Quit(args []string) {
if len(args) != 0 {
fmt.Print("Invalid number of arguments\n")
return
}
os.Exit(0)
}
 
// Resolves aliases and dispatches to the correct handler
func (g *Game) Dispatch(args []string) {
seen := make(map[string]bool)
name := args[0]
for {
seen[name] = true
prefix, ok := g.Aliases[name]
if !ok {
break
}
args = append(prefix, args[1:]...)
name = args[0]
if seen[name] {
fmt.Print("Recursive alias.\n")
return
}
}
cb := g.Commands[name]
if cb == nil {
fmt.Printf("Invalid command: %q\n", name)
return
}
cb(args[1:])
return
}
 
// Set everything up
func (g *Game) Initialize() *Game {
startRoom := g.GetRoomAt(0, 0, 0)
startRoom.Name = "Start room"
startRoom.Items[SLEDGE] = 1
goalRoom := g.GetRoomAt(1, 1, 5)
goalRoom.Name = "Prize room"
g.Room = startRoom
g.Inventory = make(map[Item]int)
g.Commands = map[string]func(args []string){
"move": func(args []string) { g.Move(args) },
"attack": func(args []string) { g.Sledge(args) },
"drop": func(args []string) { g.DropItem(args) },
"take": func(args []string) { g.TakeItem(args) },
"inventory": func(args []string) { g.ShowInventory(args) },
"name": func(args []string) { g.RenameRoom(args) },
"equip": func(args []string) { g.EquipItem(args) },
"alias": func(args []string) { g.CreateAlias(args) },
"quit": func(args []string) { g.Quit(args) },
"look": func(args []string) { g.Look(args) },
"help": func(args []string) { g.Help(args) },
}
g.Aliases = map[string][]string{
"north": []string{"move", "north"},
"south": []string{"move", "south"},
"east": []string{"move", "east"},
"west": []string{"move", "west"},
"up": []string{"move", "up"},
"down": []string{"move", "down"},
"n": []string{"north"},
"s": []string{"south"},
"e": []string{"east"},
"w": []string{"west"},
"u": []string{"up"},
"d": []string{"down"},
"i": []string{"inventory"},
"inv": []string{"inventory"},
"a": []string{"attack"},
}
g.HelpText = map[string]string{
"move": "Moves you through passages.",
"attack": "Attacks a wall with the equipped Sledge hammer.",
"drop": "Drops items.",
"take": "Picks up items.",
"inventory": "Shows your inventory.",
"name": "Rename a room.",
"equip": "Equip an item.",
"alias": "Creates an alias.",
"quit": "Exits the game.",
"look": "Describes the room.",
"help": "Help about commands.",
}
return g
}
 
// Read a single line of input
func readLine(in io.Reader) (string, bool) {
var line []string
buf := []byte{0}
_, err := in.Read(buf)
for err == nil && buf[0] != '\n' && buf[0] != '\r' {
line = append(line, string(buf))
_, err = in.Read(buf)
}
if buf[0] == '\r' {
in.Read(buf)
}
return strings.Join(line, ""), err == nil
}
 
// Returns a sorted array of command and alias names
func (g *Game) GetCommands() []string {
var commandNames []string
for name := range g.Commands {
commandNames = append(commandNames, name)
}
for name := range g.Aliases {
commandNames = append(commandNames, name)
}
sort.Strings(commandNames)
return commandNames
}
 
// Main game loop
func (g *Game) Run() {
fmt.Printf("Welcome to RC Minimalist RPG, Go version %d.%d.\n",
VERSION_MAJOR, VERSION_MINOR)
fmt.Print("You start in room 0,0,0. Your goal is at 1,1,5. Good luck!\n")
fmt.Printf("Commands: %s\n", strings.Join(g.GetCommands(), ", "))
g.Room.Describe()
fmt.Print("\n> ")
line, ok := readLine(os.Stdin)
for ok && len(line) == 0 {
fmt.Print("\n> ")
line, ok = readLine(os.Stdin)
}
for ok {
tokens := strings.Split(line, " ")
g.Dispatch(tokens)
fmt.Print("\n> ")
line, ok = readLine(os.Stdin)
for ok && len(line) == 0 {
fmt.Print("\n> ")
line, ok = readLine(os.Stdin)
}
}
}
 
func main() {
g := new(Game).Initialize()
g.Run()
}