Enhance: TypeScriptの型を厳格化

etc/aiscript.api.md

@@ -347,12 +347,14 @@ type FnTypeSource = NodeBase & {
 // @public (undocumented)
 type For = NodeBase & {
     type: 'for';
-    var?: string;
-    from?: Expression;
-    to?: Expression;
-    times?: Expression;
     for: Statement | Expression;
-};
+} & ({
+    var: string;
+    from: Expression;
+    to: Expression;
+} | {
+    times: Expression;
+});
 
 // @public (undocumented)
 function getLangVersion(input: string): string | null;

src/error.ts

@@ -1,4 +1,3 @@
-import { TokenKind } from './parser/token.js';
 import type { Pos } from './node.js';
 
 export abstract class AiScriptError extends Error {
@@ -13,7 +12,7 @@
 		this.info = info;
 
 		// Maintains proper stack trace for where our error was thrown (only available on V8)
 		if (Error.captureStackTrace) {
 			Error.captureStackTrace(this, AiScriptError);
 		}
 	}
@@ -25,9 +24,12 @@
 export class NonAiScriptError extends AiScriptError {
 	public name = 'Internal';
 	constructor(error: unknown) {
-		const message = String(
-			(error as { message?: unknown } | null | undefined)?.message ?? error,
-		);
+		let message: string;
+		if (error != null && typeof error === 'object' && 'message' in error) {
+			message = String(error.message);
+		} else {
+			message = String(error);
+		}
 		super(message, error);
 	}
 }

src/interpreter/index.ts

@@ -14,7 +14,7 @@
 import { Variable } from './variable.js';
 import { Reference } from './reference.js';
 import type { JsValue } from './util.js';
-import type { Value, VFn, VUserFn } from './value.js';
+import type { Value, VFn, VFnParam } from './value.js';
 
 export type LogObject = {
 	scope?: string;
@@ -61,7 +61,7 @@
 				const q = args[0];
 				assertString(q);
 				if (this.opts.in == null) return NULL;
-				const a = await this.opts.in!(q.value);
+				const a = await this.opts.in(q.value);
 				return STR(a);
 			}),
 		};
@@ -280,15 +280,19 @@
 			// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
 			return result ?? NULL;
 		} else {
-			const fnScope = fn.scope!.createChildScope();
+			const fnScope = fn.scope.createChildScope();
 			for (const [i, param] of fn.params.entries()) {
-				const arg = args[i];
-				if (!param.default) expectAny(arg);
-				this.define(fnScope, param.dest, arg ?? param.default!, true);
+				let arg = args[i];
+				if (!param.default) {
+					expectAny(arg);
+				} else if (!arg) {
+					arg = param.default;
+				}
+				this.define(fnScope, param.dest, arg, true);
 			}
 
 			const info: CallInfo = { name: fn.name ?? '<anonymous>', pos };
-			return unWrapRet(await this._run(fn.statements!, fnScope, [...callStack, info]));
+			return unWrapRet(await this._run(fn.statements, fnScope, [...callStack, info]));
 		}
 	}
 
@@ -411,7 +415,7 @@
 
 			case 'loop': {
 				// eslint-disable-next-line no-constant-condition
 				while (true) {
 					const v = await this._run(node.statements, scope.createChildScope(), callStack);
 					if (v.type === 'break') {
 						break;
@@ -423,7 +427,7 @@
 			}
 
 			case 'for': {
-				if (node.times) {
+				if ('times' in node) {
 					const times = await this._eval(node.times, scope, callStack);
 					if (isControl(times)) {
 						return times;
@@ -438,19 +442,19 @@
 						}
 					}
 				} else {
-					const from = await this._eval(node.from!, scope, callStack);
+					const from = await this._eval(node.from, scope, callStack);
 					if (isControl(from)) {
 						return from;
 					}
-					const to = await this._eval(node.to!, scope, callStack);
+					const to = await this._eval(node.to, scope, callStack);
 					if (isControl(to)) {
 						return to;
 					}
 					assertNumber(from);
 					assertNumber(to);
 					for (let i = from.value; i < from.value + to.value; i++) {
 						const v = await this._eval(node.for, scope.createChildScope(new Map([
-							[node.var!, {
+							[node.var, {
 								isMutable: false,
 								value: NUM(i),
 							}],
@@ -604,8 +608,9 @@
 					return target;
 				}
 				if (isObject(target)) {
-					if (target.value.has(node.name)) {
-						return target.value.get(node.name)!;
+					const value = target.value.get(node.name);
+					if (value != null) {
+						return value;
 					} else {
 						return NULL;
 					}
@@ -632,8 +637,9 @@
 					return item;
 				} else if (isObject(target)) {
 					assertString(i);
-					if (target.value.has(i.value)) {
-						return target.value.get(i.value)!;
+					const value = target.value.get(i.value);
+					if (value != null) {
+						return value;
 					} else {
 						return NULL;
 					}
@@ -670,28 +676,21 @@
 			}
 
 			case 'fn': {
-				const params = await Promise.all(node.params.map(async (param) => {
-					return {
+				const params: VFnParam[] = [];
+				for (const param of node.params) {
+					const defaultValue = param.default ? await this._eval(param.default, scope, callStack) :
+						param.optional ? NULL :
+						undefined;
+					if (defaultValue != null && isControl(defaultValue)) {
+						return defaultValue;
+					}
+					params.push({
 						dest: param.dest,
-						default:
-							param.default ? await this._eval(param.default, scope, callStack) :
-							param.optional ? NULL :
-							undefined,
+						default: defaultValue,
 						// type: (TODO)
-					};
-				}));
-				const control = params
-					.map((param) => param.default)
-					.filter((value) => value != null)
-					.find(isControl);
-				if (control != null) {
-					return control;
-				}
-				return FN(
-					params as VUserFn['params'],
-					node.children,
-					scope,
-				);
+					});
+				}
+				return FN(params, node.children, scope);
 			}
 
 			case 'block': {
@@ -851,9 +850,7 @@
 
 		let v: Value | Control = NULL;
 
-		for (let i = 0; i < program.length; i++) {
-			const node = program[i]!;
-
+		for (const node of program) {
 			v = await this._eval(node, scope, callStack);
 			if (v.type === 'return') {
 				this.log('block:return', { scope: scope.name, val: v.value });
@@ -910,7 +907,7 @@
 	public pause(): void {
 		if (this.pausing) return;
 		let resolve: () => void;
 		const promise = new Promise<void>(r => { resolve = () => r(); });
 		this.pausing = { promise, resolve: resolve! };
 		for (const handler of this.pauseHandlers) {
 			handler();

src/interpreter/primitive-props.ts

@@ -9,19 +9,21 @@
 type VWithPP = VNum|VStr|VArr|VError;
 
 const PRIMITIVE_PROPS: {
-	[key in VWithPP['type']]: { [key: string]: (target: Value) => Value }
+	[key in VWithPP['type']]: Map<string, (target: Value) => Value>;
+} & {
+	[key in (Exclude<Value, VWithPP>)['type']]?: never;
 } = {
-	num: {
+	num: new Map(Object.entries({
 		to_str: (target: VNum): VFn => FN_NATIVE(async (_, _opts) => {
 			return STR(target.value.toString());
 		}),
 
 		to_hex: (target: VNum): VFn => FN_NATIVE(async (_, _opts) => {
 			return STR(target.value.toString(16));
 		}),
-	},
+	})),
 
-	str: {
+	str: new Map(Object.entries({
 		to_num: (target: VStr): VFn => FN_NATIVE(async (_, _opts) => {
 			const parsed = parseInt(target.value, 10);
 			if (isNaN(parsed)) return NULL;
@@ -90,7 +92,7 @@
 		split: (target: VStr): VFn => FN_NATIVE(async ([splitter], _opts) => {
 			if (splitter) assertString(splitter);
 			if (splitter) {
 				return ARR(target.value.split(splitter ? splitter.value : '').map(s => STR(s)));
 			} else {
 				return ARR(toArray(target.value).map(s => STR(s)));
 			}
@@ -168,9 +170,9 @@
 
 			return STR(target.value.padEnd(width.value, s));
 		}),
-	},
+	})),
 
-	arr: {
+	arr: new Map(Object.entries({
 		len: (target: VArr): VNum => NUM(target.value.length),
 
 		push: (target: VArr): VFn => FN_NATIVE(async ([val], _opts) => {
@@ -219,9 +221,8 @@
 
 		filter: (target: VArr): VFn => FN_NATIVE(async ([fn], opts) => {
 			assertFunction(fn);
-			const vals = [] as Value[];
-			for (let i = 0; i < target.value.length; i++) {
-				const item = target.value[i]!;
+			const vals: Value[] = [];
+			for (const [i, item] of target.value.entries()) {
 				const res = await opts.call(fn, [item, NUM(i)]);
 				assertBoolean(res);
 				if (res.value) vals.push(item);
@@ -243,8 +244,7 @@
 
 		find: (target: VArr): VFn => FN_NATIVE(async ([fn], opts) => {
 			assertFunction(fn);
-			for (let i = 0; i < target.value.length; i++) {
-				const item = target.value[i]!;
+			for (const [i, item] of target.value.entries()) {
 				const res = await opts.call(fn, [item, NUM(i)]);
 				assertBoolean(res);
 				if (res.value) return item;
@@ -312,7 +312,7 @@
 			return target;
 		}),
 
 		fill: (target: VArr): VFn => FN_NATIVE(async ([val, st, ed], opts) => {
 			const value = val ?? NULL;
 			const start = st && (assertNumber(st), st.value);
 			const end = ed && (assertNumber(ed), ed.value);
@@ -320,7 +320,7 @@
 			return target;
 		}),
 
 		repeat: (target: VArr): VFn => FN_NATIVE(async ([times], opts) => {
 			assertNumber(times);
 			try {
 				return ARR(Array(times.value).fill(target.value).flat());
@@ -331,7 +331,7 @@
 			}
 		}),
 
 		splice: (target: VArr): VFn => FN_NATIVE(async ([idx, rc, vs], opts) => {
 			assertNumber(idx);
 			const index = (idx.value < -target.value.length) ? 0
 				: (idx.value < 0) ? target.value.length + idx.value
@@ -347,7 +347,7 @@
 			return ARR(result);
 		}),
 
 		flat: (target: VArr): VFn => FN_NATIVE(async ([depth], opts) => {
 			depth = depth ?? NUM(1);
 			assertNumber(depth);
 			if (!Number.isInteger(depth.value)) throw new AiScriptRuntimeError('arr.flat expected integer, got non-integer');
@@ -382,8 +382,7 @@
 
 		every: (target: VArr): VFn => FN_NATIVE(async ([fn], opts) => {
 			assertFunction(fn);
-			for (let i = 0; i < target.value.length; i++) {
-				const item = target.value[i]!;
+			for (const [i, item] of target.value.entries()) {
 				const res = await opts.call(fn, [item, NUM(i)]);
 				assertBoolean(res);
 				if (!res.value) return FALSE;
@@ -393,8 +392,7 @@
 
 		some: (target: VArr): VFn => FN_NATIVE(async ([fn], opts) => {
 			assertFunction(fn);
-			for (let i = 0; i < target.value.length; i++) {
-				const item = target.value[i]!;
+			for (const [i, item] of target.value.entries()) {
 				const res = await opts.call(fn, [item, NUM(i)]);
 				assertBoolean(res);
 				if (res.value) return TRUE;
@@ -423,20 +421,21 @@
 			assertNumber(index);
 			return target.value.at(index.value) ?? otherwise ?? NULL;
 		}),
-	},
+	})),
 
-	error: {
+	error: new Map(Object.entries({
 		name: (target: VError): VStr => STR(target.value), 
 
 		info: (target: VError): Value => target.info ?? NULL,
-	},
+	})),
 } as const;
 
 export function getPrimProp(target: Value, name: string): Value {
-	if (Object.hasOwn(PRIMITIVE_PROPS, target.type)) {
-		const props = PRIMITIVE_PROPS[target.type as VWithPP['type']];
-		if (Object.hasOwn(props, name)) {
-			return props[name]!(target);
+	const props = PRIMITIVE_PROPS[target.type];
+	if (props != null) {
+		const prop = props.get(name);
+		if (prop != null) {
+			return prop(target);
 		} else {
 			throw new AiScriptRuntimeError(`No such prop (${name}) in ${target.type}.`);
 		}

src/interpreter/scope.ts

@@ -4,17 +4,19 @@ import type { Value } from './value.js';
 import type { Variable } from './variable.js';
 import type { LogObject } from './index.js';
 
+export type LayerdStates = [Map<string, Variable>, ...Map<string, Variable>[]]
+
 export class Scope {
 	private parent?: Scope;
-	private layerdStates: Map<string, Variable>[];
+	private layerdStates: LayerdStates;
 	public name: string;
 	public opts: {
 		log?(type: string, params: LogObject): void;
 		onUpdated?(name: string, value: Value): void;
 	} = {};
 	public nsName?: string;
 
-	constructor(layerdStates: Scope['layerdStates'] = [], parent?: Scope, name?: Scope['name'], nsName?: string) {
+	constructor(layerdStates: Scope['layerdStates'] = [new Map()], parent?: Scope, name?: Scope['name'], nsName?: string) {
 		this.layerdStates = layerdStates;
 		this.parent = parent;
 		this.name = name || (layerdStates.length === 1 ? '<root>' : '<anonymous>');
@@ -41,13 +43,13 @@ export class Scope {
 
 	@autobind
 	public createChildScope(states: Map<string, Variable> = new Map(), name?: Scope['name']): Scope {
-		const layer = [states, ...this.layerdStates];
+		const layer: LayerdStates = [states, ...this.layerdStates];
 		return new Scope(layer, this, name);
 	}
 
 	@autobind
 	public createChildNamespaceScope(nsName: string, states: Map<string, Variable> = new Map(), name?: Scope['name']): Scope {
-		const layer = [states, ...this.layerdStates];
+		const layer: LayerdStates = [states, ...this.layerdStates];
 		return new Scope(layer, this, name, nsName);
 	}
 
@@ -58,8 +60,9 @@ export class Scope {
 	@autobind
 	public get(name: string): Value {
 		for (const layer of this.layerdStates) {
-			if (layer.has(name)) {
-				const state = layer.get(name)!.value;
+			const value = layer.get(name);
+			if (value) {
+				const state = value.value;
 				this.log('read', { var: name, val: state });
 				return state;
 			}
@@ -103,7 +106,7 @@ export class Scope {
 	public getAll(): Map<string, Variable> {
 		const vars = this.layerdStates.reduce((arr, layer) => {
 			return [...arr, ...layer];
-		}, [] as [string, Variable][]);
+		}, [] satisfies [string, Variable][]);
 		return new Map(vars);
 	}
 
@@ -115,7 +118,7 @@ export class Scope {
 	@autobind
 	public add(name: string, variable: Variable): void {
 		this.log('add', { var: name, val: variable });
-		const states = this.layerdStates[0]!;
+		const states = this.layerdStates[0];
 		if (states.has(name)) {
 			throw new AiScriptRuntimeError(
 				`Variable '${name}' already exists in scope '${this.name}'`,
@@ -135,8 +138,8 @@ export class Scope {
 	public assign(name: string, val: Value): void {
 		let i = 1;
 		for (const layer of this.layerdStates) {
-			if (layer.has(name)) {
-				const variable = layer.get(name)!;
+			const variable = layer.get(name);
+			if (variable != null) {
 				if (!variable.isMutable) {
 					throw new AiScriptRuntimeError(`Cannot assign to an immutable variable ${name}.`);
 				}