Refactor player and room to support adding effects.

Container.ts

@@ -1,29 +0,0 @@
-import type { Item } from "./data/data.ts";
-
-export default class Container {
-	protected items: Item[];
-
-	constructor(items: Item[]) {
-		this.items = items;
-	}
-
-	description(items: Item[]): string | null {
-		if (items.length === 0) return null;
-
-		const vowels = ["a", "e", "i", "o", "u"];
-		const description = items
-			.map(({ name }, i) => {
-				let anItem = `${vowels.includes(name[0]) ? "an" : "a"} ${name}`;
-
-				// if we have more than one item, and this is the last item...
-				if (i > 1 && i + 1 === items.length) {
-					anItem = `and ${anItem}`;
-				}
-
-				return anItem;
-			})
-			.join(", ");
-
-		return description;
-	}
-}

Game.ts

@@ -0,0 +1,18 @@
+import type Player from "./Player.ts";
+import type Scene from "./Scene.ts";
+
+export default class Game {
+	#player: Player;
+	#scene: Scene;
+
+	constructor(player: Player, scene: Scene) {
+		this.#player = player;
+		this.#scene = scene;
+	}
+
+	lookAtScene(): string {
+		const { effects } = this.#player;
+
+		return this.#scene.look(effects);
+	}
+}

Interpreter.ts

@@ -1,5 +1,5 @@
-import Player from "./Player.ts";
-import Scene from "./Scene.ts";
+import type Player from "./Player.ts";
+import type Scene from "./Scene.ts";
 import { terms } from "./terms/terms.ts";
 import type {
 	Action,

Player.ts

@@ -1,21 +1,21 @@
-import { Item } from "./data/data.ts";
-import Container from "./Container.ts";
-import User from "./User.ts";
+import { Effect, Item, VesselProperties } from "./types.ts";
+import Vessel from "./Vessel.ts";
 
-export default class Player extends Container {
-	#user: User;
+export default class Player extends Vessel<VesselProperties> {
+	#effects: Effect<VesselProperties>[];
 
-	constructor(items?: Item[]) {
-		super(items || []);
-		this.#user = new User();
+	constructor(items: Item[] = [], effects: Effect<VesselProperties>[] = []) {
+		super({ items }, { effects: [] });
+
+		this.#effects = effects;
 	}
 
-	put(item: Item) {
-		this.items.push(item);
+	get effects() {
+		return this.#effects;
 	}
 
 	look(): string {
-		const description = super.description(this.items);
+		const description = super.description(this._properties.items || []);
 
 		if (description) {
 			return `You have ${description}`;
@@ -23,4 +23,9 @@ export default class Player extends Container {
 			return "You have nothing.";
 		}
 	}
+
+	put(item: Item) {
+		if (!this._properties.items) this._properties.items = [];
+		this._properties.items.push(item);
+	}
 }

Scene.ts

@@ -1,32 +1,46 @@
-import { GameData, Item } from "./data/data.ts";
-import Container from "./Container.ts";
+import { GameData, Item, SceneProperties } from "./types.ts";
+import Vessel from "./Vessel.ts";
 
-export default class Scene extends Container {
-	#roomDescription: string;
+export default class Scene extends Vessel<SceneProperties> {
+	#isViewed: boolean;
 
-	constructor(gameData: GameData) {
-		super(gameData.items);
-
-		this.#roomDescription = gameData.description;
+	constructor(gameData: GameData<SceneProperties>) {
+		// TODO: [] is a placeholder for scene effects.
+		super(gameData.properties, gameData.conditions);
+		this.#isViewed = false;
 	}
 
-	look(): string {
-		const itemsDescription = super.description(this.items);
-		let description = this.#roomDescription;
+	look(activePlayerEffects: string[], activeSceneEffects: string[]): string {
+		const properties = this.applyEffects(
+			activePlayerEffects,
+			activeSceneEffects
+		);
+		const itemsDescription = super.description(properties.items || []);
+		const { description, shortDescription } = properties;
 
-		if (itemsDescription) {
-			description += `\n\nThere is ${itemsDescription}`;
+		let fullDescription = description || "Nothing to see here...";
+
+		if (this.#isViewed && shortDescription) {
+			fullDescription = shortDescription;
+		} else if (description) {
+			this.#isViewed = true;
+			fullDescription = description;
 		}
 
-		return description;
+		if (itemsDescription) {
+			fullDescription += `\n\nThere is ${itemsDescription}`;
+		}
+
+		return fullDescription;
 	}
 
 	get(target: string): Item | null {
-		const idx = this.items.findIndex(({ name }) => name === target);
+		const { items = [] } = this._properties;
+		const idx = items.findIndex(({ name }) => name === target);
 
 		if (idx >= 0) {
-			const item = this.items[idx];
-			this.items.splice(idx, 1);
+			const item = items[idx];
+			items.splice(idx, 1);
 
 			return item;
 		}

State.ts

@@ -0,0 +1,13 @@
+import { GameData, SceneProperties } from "./types.ts";
+import Player from "./Player.ts";
+import Scene from "./Scene.ts";
+
+export class State {
+	#player: Player;
+	#scene: Scene;
+
+	constructor(gameData: GameData<SceneProperties>) {
+		this.#player = new Player();
+		this.#scene = new Scene(gameData);
+	}
+}

Vessel.ts

@@ -0,0 +1,65 @@
+import type { Conditions, Effect, Item, VesselProperties } from "./types.ts";
+
+export default class Vessel<T extends VesselProperties> {
+	protected _conditions: Conditions<T>;
+	protected _properties: T;
+	protected _activeEffects: string[];
+
+	constructor(
+		properties: T,
+		conditions: Conditions<T>,
+		activeEffects: string[] = []
+	) {
+		this._conditions = conditions;
+		this._properties = properties;
+		this._activeEffects = activeEffects;
+	}
+
+	get activeEffects(): string[] {
+		return this._activeEffects;
+	}
+
+	description(items: Item[]): string | null {
+		if (items.length === 0) return null;
+
+		const vowels = ["a", "e", "i", "o", "u"];
+		const description = items
+			.map(({ name }, i) => {
+				let anItem = `${vowels.includes(name[0]) ? "an" : "a"} ${name}`;
+
+				// if we have more than one item, and this is the last item...
+				if (i > 1 && i + 1 === items.length) {
+					anItem = `and ${anItem}`;
+				}
+
+				return anItem;
+			})
+			.join(", ");
+
+		return description;
+	}
+
+	// Player effects should be applied first, then scene effects should be applied.
+	// This will mean that scene effects will take precedence over player effects.
+	applyEffects(
+		activePlayerEffects: string[],
+		activeSceneEffects: string[]
+	): T {
+		const activeEffects = [...activePlayerEffects, ...activeSceneEffects];
+		const map = this._conditions.effects.reduce(
+			(map: { [name: string]: Effect<T> }, effect: Effect<T>) => {
+				map[effect.name] = effect;
+				return map;
+			},
+			{}
+		);
+		const effects = activeEffects.map((e) => map[e]);
+		const appliedProperties = { ...this._properties };
+
+		for (const effect of effects) {
+			Object.assign(appliedProperties, effect.properties);
+		}
+
+		return appliedProperties;
+	}
+}

data/data.ts

@@ -1,10 +0,0 @@
-export * from "./rooms.ts";
-
-export interface Item {
-	name: string;
-}
-
-export interface GameData {
-	description: string;
-	items: Item[];
-}

data/rooms.ts

@@ -1,8 +1,22 @@
-import { GameData } from "./data.ts";
+import { GameData, SceneProperties } from "../types.ts";
 
-export const hall: GameData = {
-	description:
-		"You are standing in a big hall. There's lots of nooks, crannies, and" +
-		"room for general testing. Aw yeah... sweet testing!",
-	items: [{ name: "flashlight" }],
+export const hall: GameData<SceneProperties> = {
+	properties: {
+		description: "It's very dark",
+		items: [{ name: "flashlight" }],
+	},
+	conditions: {
+		effects: [
+			{
+				name: "lights-on",
+				properties: {
+					description:
+						"You are standing in a big hall. There's lots of nooks, " +
+						"crannies, and room for general testing. Aw yeah... sweet testing!",
+					shortDescription: "You are in a big hall.",
+				},
+				source: "player",
+			},
+		],
+	},
 };

main.ts

@@ -2,7 +2,7 @@ import Interpreter from "./Interpreter.ts";
 import Player from "./Player.ts";
 import Scene from "./Scene.ts";
 import User from "./User.ts";
-import { hall } from "./data/data.ts";
+import { hall } from "./types.ts";
 
 async function main() {
 	const user = new User(); // for communication with the user

terms/actions.ts

@@ -1,8 +1,8 @@
 import Scene from "../Scene.ts";
 import Player from "../Player.ts";
 
-export function look(_player: Player, scene: Scene): string {
-	return scene.look();
+export function look(player: Player, scene: Scene): string {
+	return scene.look(player.activeEffects, scene.activeEffects);
 }
 
 export function pickUpItem(

terms/terms.ts

@@ -21,8 +21,8 @@ const look: Action = {
 
 const take: Action = {
 	action: actions.pickUpItem,
-	category: "action",
 	canPrecedeVariable: true,
+	category: "action",
 	constant: "take",
 	precedesCategories: [],
 	precedesConstants: [],

types.ts

@@ -0,0 +1,29 @@
+export * from "./data/rooms.ts";
+
+export interface Item {
+	name: string;
+}
+
+export interface Effect<T> {
+	name: string;
+	properties: T;
+	source: "player" | "scene";
+}
+
+export interface VesselProperties {
+	items?: Item[];
+}
+
+export interface SceneProperties extends VesselProperties {
+	description?: string;
+	shortDescription?: string;
+}
+
+export interface Conditions<T> {
+	effects: Effect<T>[];
+}
+
+export interface GameData<T> {
+	conditions: Conditions<T>;
+	properties: SceneProperties;
+}