Use more readonly

Close #48.

scripts/train/Experience.ts

@@ -2,13 +2,13 @@
 export interface Experience
 {
     /** State in which the action was taken. */
-    state: number[];
+    state: readonly number[];
     /** ID of the Choice that was taken. */
     action: number;
     /** Reward gained from the action. */
     reward: number;
     /** Next state after taking the action. */
-    nextState: number[];
+    nextState: readonly number[];
     /** ID of the best action that will be taken in the next state. */
     nextAction: number;
 }

scripts/train/TrainBattle.ts

@@ -15,7 +15,7 @@ import { TrainNetwork } from "./TrainNetwork";
 export class TrainBattle extends PSBattle
 {
     /** Buffer of Experience objects. */
-    public get experiences(): ReadonlyArray<Experience>
+    public get experiences(): readonly Experience[]
     {
         return this._experiences;
     }

scripts/train/TrainNetwork.ts

@@ -6,9 +6,9 @@ import { Experience } from "./Experience";
 export class TrainNetwork extends Network
 {
     /** Tensor data that generated `lastPrediction`. */
-    private lastStateData?: number[];
+    private lastStateData?: readonly number[];
     /** Tensor data that generated `prediction`. */
-    private stateData?: number[];
+    private stateData?: readonly number[];
     /**
      * Whether to update `#lastStateData` on `#getPrediction()`. Resets back to
      * true once that method is called.

scripts/train/index.ts

@@ -67,21 +67,21 @@ logStream.write = function(chunk: any, enc?: string | CB, cb?: CB)
 };
 
 /** Models to represent p1 and p2. */
-type Models = {[P in PlayerID]: tf.LayersModel};
+type Models = {readonly [P in PlayerID]: tf.LayersModel};
 
 interface GameOptions extends Models
 {
     /** Maximum amount of turns before the game is considered a tie. */
-    maxTurns: number;
+    readonly maxTurns: number;
     /**
      * Whether to emit Experience objects, which will be used for learning
      * later.
      */
-    emitExperiences?: boolean;
+    readonly emitExperiences?: boolean;
     /** Path to the file in which to store debug info. */
-    logPath?: string;
+    readonly logPath?: string;
     /** Logger object. */
-    logger?: Logger;
+    readonly logger?: Logger;
 }
 
 /** Result object returned from `play()`. */
@@ -208,7 +208,7 @@ async function play(options: GameOptions): Promise<GameResult>
  * too much.
  * @param epochs Number of epochs to run.
  */
-async function learn(model: tf.LayersModel, experiences: Experience[],
+async function learn(model: tf.LayersModel, experiences: readonly Experience[],
     gamma: number, epochs: number): Promise<tf.History>
 {
     const dataset = datasetFromIteratorFn<tf.TensorContainerObject>(

src/ai/Network.ts

@@ -125,14 +125,15 @@ to create a new model with an output shape of (null, ${intToChoice.length})`);
     }
 
     /** Ensures that a network input shape is valid. */
-    private static isValidInputShape(shape: (number | null)[]): boolean
+    private static isValidInputShape(shape: readonly (number | null)[]): boolean
     {
         return shape.length === 2 && shape[0] === null &&
             shape[1] === sizeBattleState;
     }
 
     /** Ensures that a network output shape is valid. */
-    private static isValidOutputShape(shape: (number | null)[]): boolean
+    private static isValidOutputShape(shape: readonly (number | null)[]):
+        boolean
     {
         return shape.length === 2 && shape[0] === null &&
             shape[1] === intToChoice.length;

src/battle/agent/Choice.ts

@@ -1,17 +1,14 @@
-const choiceIdsInternal =
+/** Maps a choice name to its id number. */
+export const choiceIds =
 {
     "move 1": 0, "move 2": 1, "move 3": 2, "move 4": 3, "switch 2": 4,
     "switch 3": 5, "switch 4": 6, "switch 5": 7, "switch 6": 8
-};
-
+} as const;
 /** The types of choices that can be made by the user. */
-export type Choice = keyof typeof choiceIdsInternal;
-
-/** Maps a choice name to its id number. */
-export const choiceIds: Readonly<typeof choiceIdsInternal> = choiceIdsInternal;
+export type Choice = keyof typeof choiceIds;
 
 /** Maps a choice id number to its name. */
-export const intToChoice: ReadonlyArray<Choice> = (function()
+export const intToChoice: readonly Choice[] = (function()
 {
     const result: Choice[] = [];
     (Object.keys(choiceIds) as Choice[]).forEach(

src/battle/dex/dex-types.ts

@@ -1,16 +1,15 @@
 /** Names of certain stats. */
 export type StatName = "hp" | "atk" | "def" | "spa" | "spd" | "spe";
 
-const typesInternal =
+/** Set of Type names. Each type has a 0-based unique index. */
+export const types =
 {
     bug: 0, dark: 1, dragon: 2, fire: 3, flying: 4, ghost: 5, electric: 6,
     fighting: 7, grass: 8, ground: 9, ice: 10, normal: 11, poison: 12,
     psychic: 13, rock: 14, steel: 15, water: 16, "???": 17
-};
-/** Set of Type names. Each type has a 0-based unique index. */
-export const types: Readonly<typeof typesInternal> = typesInternal;
+} as const;
 /** The different types a pokemon can have. */
-export type Type = keyof typeof typesInternal;
+export type Type = keyof typeof types;
 
 /** Set of HPType names. Each type has a 0-based unique index. */
 export const hpTypes =
@@ -31,17 +30,13 @@ export const weatherItems: {readonly [T in WeatherType]: string} =
     Sandstorm: "smoothrock", Hail: "icyrock"
 };
 
-const majorStatusesInternal =
+/** Hold the set of all major status names. Empty string means no status. */
+export const majorStatuses =
 {
     "": 0, brn: 1, par: 2, psn: 3, tox: 4, slp: 5, frz: 6
-};
-/** Hold the set of all major status names. Empty string means no status. */
-export const majorStatuses: Readonly<typeof majorStatusesInternal> =
-    majorStatusesInternal;
-
+} as const;
 /** Major pokemon status conditions. */
 export type MajorStatus = keyof typeof majorStatuses;
-
 /**
  * Checks if a value matches a major status.
  * @param status Value to be checked.
@@ -52,18 +47,20 @@ export function isMajorStatus(status: any): status is MajorStatus
     return majorStatuses.hasOwnProperty(status);
 }
 
-const boostNamesInternal =
+/** Holds the set of all boostable stat names. */
+export const statsExceptHP =
+    {atk: true, def: true, spa: true, spd: true, spe: true} as const;
+/** Names of pokemon stats that can be boosted. */
+export type StatExceptHP = keyof typeof statsExceptHP;
+
+/** Holds the set of all boostable stat names. */
+export const boostNames =
 {
     atk: true, def: true, spa: true, spd: true, spe: true, accuracy: true,
     evasion: true
-};
-/** Holds the set of all boostable stat names. */
-export const boostNames: Readonly<typeof boostNamesInternal> =
-    boostNamesInternal;
-
+} as const;
 /** Names of pokemon stats that can be boosted. */
 export type BoostName = keyof typeof boostNames;
-
 /**
  * Checks if a value matches a boost name.
  * @param stat Value to be checked.
@@ -74,16 +71,13 @@ export function isBoostName(stat: any): stat is BoostName
     return boostNames.hasOwnProperty(stat);
 }
 
-const weatherTypesInternal =
-    {none: true, SunnyDay: true, RainDance: true, Sandstorm: true, Hail: true};
-
 /** Holds the set of all weather types. */
-export const weatherTypes: Readonly<typeof weatherTypesInternal> =
-    weatherTypesInternal;
-
+export const weatherTypes =
+{
+    none: true, SunnyDay: true, RainDance: true, Sandstorm: true, Hail: true
+} as const;
 /** Types of weather conditions. */
 export type WeatherType = keyof typeof weatherTypes;
-
 /**
  * Checks if a value matches a weather type.
  * @param type Value to be checked.
@@ -112,11 +106,11 @@ export interface PokemonData
     /** Letter of the alternate form. */
     readonly formLetter?: string;
     /** Alternate forms of this pokemon. */
-    readonly otherForms?: ReadonlyArray<string>;
+    readonly otherForms?: readonly string[];
     /** Id names of the abilities this species can have. */
-    readonly abilities: ReadonlyArray<string>;
+    readonly abilities: readonly string[];
     /** Types of the pokemon. */
-    readonly types: Readonly<[Type, Type]>;
+    readonly types: readonly [Type, Type];
     /** Base stats. */
     readonly baseStats: {readonly [S in StatName]: number};
     /** Pokemon's weight in kg. Affected by certain moves. */

src/battle/state/Pokemon.ts

@@ -75,13 +75,13 @@ ability ${ability}`);
         () => { if (this.active) this.setOverrideAbility(); });
 
     /** The types of this pokemon. */
-    public get types(): ReadonlyArray<Type>
+    public get types(): readonly Type[]
     {
         // uninitialized Pokemon objs should silently fail so toArray() doesn't
         //  throw
         if (!this.species.definiteValue) return [];
 
-        let result: ReadonlyArray<Type>;
+        let result: readonly Type[];
         if (this._active)
         {
             result = this.volatile.overrideTypes
@@ -92,7 +92,7 @@ ability ${ability}`);
         return result.filter(type => type !== "???");
     }
     /** Temporarily changes primary and secondary types and resets third. */
-    public changeType(newTypes: [Type, Type]): void
+    public changeType(newTypes: readonly [Type, Type]): void
     {
         this.volatile.overrideTypes = newTypes;
         // reset added type
@@ -125,7 +125,8 @@ ability ${ability}`);
      * @param targets Targets of the move.
      * @param nopp Whether to not consume pp for this move.
      */
-    public useMove(id: string, targets: Pokemon[], nopp?: boolean): void
+    public useMove(id: string, targets: readonly Pokemon[], nopp?: boolean):
+        void
     {
         // struggle doesn't occupy a moveslot
         if (id === "struggle") return;

src/battle/state/PossibilityClass.ts

@@ -65,7 +65,7 @@ export class PossibilityClass<TData>
     }
 
     /** Removes currently set value names that are not in the given array. */
-    public narrow(...values: string[]): void
+    public narrow(...values: readonly string[]): void
     {
         values.forEach(x => this.check(x));
 

src/battle/state/Team.ts

@@ -7,7 +7,7 @@ import { TeamStatus } from "./TeamStatus";
 export interface SwitchInOptions
 {
     /** Whether volatile status should be copied onto the replacing pokemon. */
-    copyVolatile?: boolean;
+    readonly copyVolatile?: boolean;
 }
 
 /** Team state. */

src/battle/state/VolatileStatus.ts

@@ -1,4 +1,4 @@
-import { dex, twoTurnMoves } from "../dex/dex";
+import { dex, TwoTurnMove, twoTurnMoves } from "../dex/dex";
 import { BoostName, Type } from "../dex/dex-types";
 import { Moveset } from "./Moveset";
 import { pluralTurns } from "./utility";
@@ -128,7 +128,7 @@ export class VolatileStatus
     /** Clears the disabled status. */
     public enableMoves(): void { this._disableTurns.fill(0); }
     /** Turns for the disable status on each move. */
-    public get disableTurns(): number[] { return this._disableTurns; }
+    public get disableTurns(): readonly number[] { return this._disableTurns; }
     // ctor will initialize values
     private readonly _disableTurns = new Array<number>(Moveset.maxSize);
 
@@ -146,17 +146,17 @@ export class VolatileStatus
     private _lockedMoveTurns!: number;
 
     /** Two-turn move currently being prepared. */
-    public get twoTurn(): keyof typeof twoTurnMoves | ""
+    public get twoTurn(): TwoTurnMove | ""
     {
         return this._twoTurn;
     }
-    public set twoTurn(twoTurn: keyof typeof twoTurnMoves | "")
+    public set twoTurn(twoTurn: TwoTurnMove | "")
     {
         this._twoTurn = twoTurn;
         // after this turn this will be 1
         this.twoTurnCounter = twoTurn ? 2 : 0;
     }
-    private _twoTurn!: keyof typeof twoTurnMoves | "";
+    private _twoTurn!: TwoTurnMove | "";
     private twoTurnCounter!: number;
 
     /** Whether this pokemon must recharge on the next turn. */
@@ -182,7 +182,7 @@ export class VolatileStatus
      * since the parent Pokemon object should handle that. Should not be
      * accessed other than by the parent Pokemon object.
      */
-    public overrideTypes!: Readonly<[Type, Type]>;
+    public overrideTypes!: readonly [Type, Type];
     /** Temporary third type. */
     public addedType!: Type;
 

src/psbot/PSEventHandler.ts

@@ -277,8 +277,8 @@ export class PSEventHandler
             const team = this.getTeam(event.id.owner);
 
             // consume pending copyvolatile status flags
-            const options: SwitchInOptions = {};
-            options.copyVolatile = team.status.selfSwitch === "copyvolatile";
+            const options: SwitchInOptions =
+                {copyVolatile: team.status.selfSwitch === "copyvolatile"};
             team.status.selfSwitch = false;
 
             team.switchIn(event.details.species, event.details.level,
@@ -415,7 +415,7 @@ export class PSEventHandler
      * Processes BattleEvents sent from the server to update the internal
      * BattleState.
      */
-    public handleEvents(events: AnyBattleEvent[]): void
+    public handleEvents(events: readonly AnyBattleEvent[]): void
     {
         // this field should only stay true if one of these events contains a
         //  |turn| message