feat: ラベル構文の追加

etc/aiscript.api.md

@@ -215,6 +215,7 @@ type Attribute = NodeBase & {
 // @public (undocumented)
 type Block = NodeBase & {
     type: 'block';
+    label?: string;
     statements: (Statement | Expression)[];
 };
 
@@ -230,6 +231,8 @@ type Bool = NodeBase & {
 // @public (undocumented)
 type Break = NodeBase & {
     type: 'break';
+    label?: string;
+    expr?: Expression;
 };
 
 // @public (undocumented)
@@ -242,6 +245,7 @@ type Call = NodeBase & {
 // @public (undocumented)
 type Continue = NodeBase & {
     type: 'continue';
+    label?: string;
 };
 
 // @public (undocumented)
@@ -264,6 +268,7 @@ type Div = NodeBase & {
 // @public (undocumented)
 type Each = NodeBase & {
     type: 'each';
+    label?: string;
     var: Expression;
     items: Expression;
     for: Statement | Expression;
@@ -347,6 +352,7 @@ type FnTypeSource = NodeBase & {
 // @public (undocumented)
 type For = NodeBase & {
     type: 'for';
+    label?: string;
     var?: string;
     from?: Expression;
     to?: Expression;
@@ -380,6 +386,7 @@ type Identifier = NodeBase & {
 // @public (undocumented)
 type If = NodeBase & {
     type: 'if';
+    label?: string;
     cond: Expression;
     then: Statement | Expression;
     elseif: {
@@ -479,6 +486,7 @@ type Loc = {
 // @public (undocumented)
 type Loop = NodeBase & {
     type: 'loop';
+    label?: string;
     statements: (Statement | Expression)[];
 };
 
@@ -499,6 +507,7 @@ type Lteq = NodeBase & {
 // @public (undocumented)
 type Match = NodeBase & {
     type: 'match';
+    label?: string;
     about: Expression;
     qs: {
         q: Expression;

src/interpreter/control.ts

@@ -1,4 +1,5 @@
 import { AiScriptRuntimeError } from '../error.js';
+import { NULL } from './value.js';
 import type { Reference } from './reference.js';
 import type { Value } from './value.js';
 
@@ -9,11 +10,13 @@ export type CReturn = {
 
 export type CBreak = {
 	type: 'break';
-	value: null;
+	label?: string;
+	value?: Value;
 };
 
 export type CContinue = {
 	type: 'continue';
+	label?: string;
 	value: null;
 };
 
@@ -25,16 +28,28 @@ export const RETURN = (v: CReturn['value']): CReturn => ({
 	value: v,
 });
 
-export const BREAK = (): CBreak => ({
+export const BREAK = (label?: string, value?: CBreak['value']): CBreak => ({
 	type: 'break' as const,
-	value: null,
+	label,
+	value: value,
 });
 
-export const CONTINUE = (): CContinue => ({
+export const CONTINUE = (label?: string): CContinue => ({
 	type: 'continue' as const,
+	label,
 	value: null,
 });
 
+/**
+ * 値がbreakで、ラベルが一致する場合のみ、その中身を取り出します。
+ */
+export function unWrapLabeledBreak(v: Value | Control, label: string | undefined): Value | Control {
+	if (v.type === 'break' && v.label != null && v.label === label) {
+		return v.value ?? NULL;
+	}
+	return v;
+}
+
 export function unWrapRet(v: Value | Control): Value {
 	switch (v.type) {
 		case 'return':

src/interpreter/index.ts

@@ -7,7 +7,7 @@
 import * as Ast from '../node.js';
 import { Scope } from './scope.js';
 import { std } from './lib/std.js';
-import { RETURN, unWrapRet, BREAK, CONTINUE, assertValue, isControl, type Control } from './control.js';
+import { RETURN, unWrapRet, BREAK, CONTINUE, assertValue, isControl, type Control, unWrapLabeledBreak } from './control.js';
 import { assertNumber, assertString, assertFunction, assertBoolean, assertObject, assertArray, eq, isObject, isArray, expectAny, reprValue, isFunction } from './util.js';
 import { NULL, FN_NATIVE, BOOL, NUM, STR, ARR, OBJ, FN, ERROR } from './value.js';
 import { getPrimProp } from './primitive-props.js';
@@ -371,7 +371,7 @@
 				}
 				assertBoolean(cond);
 				if (cond.value) {
-					return this._evalClause(node.then, scope, callStack);
+					return unWrapLabeledBreak(await this._evalClause(node.then, scope, callStack), node.label);
 				}
 				for (const elseif of node.elseif) {
 					const cond = await this._eval(elseif.cond, scope, callStack);
@@ -380,11 +380,11 @@
 					}
 					assertBoolean(cond);
 					if (cond.value) {
-						return this._evalClause(elseif.then, scope, callStack);
+						return unWrapLabeledBreak(await this._evalClause(elseif.then, scope, callStack), node.label);
 					}
 				}
 				if (node.else) {
-					return this._evalClause(node.else, scope, callStack);
+					return unWrapLabeledBreak(await this._evalClause(node.else, scope, callStack), node.label);
 				}
 				return NULL;
 			}
@@ -400,21 +400,28 @@
 						return q;
 					}
 					if (eq(about, q)) {
-						return await this._evalClause(qa.a, scope, callStack);
+						return unWrapLabeledBreak(await this._evalClause(qa.a, scope, callStack), node.label);
 					}
 				}
 				if (node.default) {
-					return await this._evalClause(node.default, scope, callStack);
+					return unWrapLabeledBreak(await this._evalClause(node.default, scope, callStack), node.label);
 				}
 				return NULL;
 			}
 
 			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') {
+						if (v.label != null && v.label !== node.label) {
+							return v;
+						}
 						break;
+					} else if (v.type === 'continue') {
+						if (v.label != null && v.label !== node.label) {
+							return v;
+						}
 					} else if (v.type === 'return') {
 						return v;
 					}
@@ -432,7 +439,14 @@
 					for (let i = 0; i < times.value; i++) {
 						const v = await this._evalClause(node.for, scope, callStack);
 						if (v.type === 'break') {
+							if (v.label != null && v.label !== node.label) {
+								return v;
+							}
 							break;
+						} else if (v.type === 'continue') {
+							if (v.label != null && v.label !== node.label) {
+								return v;
+							}
 						} else if (v.type === 'return') {
 							return v;
 						}
@@ -456,7 +470,14 @@
 							}],
 						])), callStack);
 						if (v.type === 'break') {
+							if (v.label != null && v.label !== node.label) {
+								return v;
+							}
 							break;
+						} else if (v.type === 'continue') {
+							if (v.label != null && v.label !== node.label) {
+								return v;
+							}
 						} else if (v.type === 'return') {
 							return v;
 						}
@@ -476,7 +497,14 @@
 					this.define(eachScope, node.var, item, false);
 					const v = await this._eval(node.for, eachScope, callStack);
 					if (v.type === 'break') {
+						if (v.label != null && v.label !== node.label) {
+							return v;
+						}
 						break;
+					} else if (v.type === 'continue') {
+						if (v.label != null && v.label !== node.label) {
+							return v;
+						}
 					} else if (v.type === 'return') {
 						return v;
 					}
@@ -695,7 +723,7 @@
 			}
 
 			case 'block': {
-				return this._run(node.statements, scope.createChildScope(), callStack);
+				return unWrapLabeledBreak(await this._run(node.statements, scope.createChildScope(), callStack), node.label);
 			}
 
 			case 'exists': {
@@ -728,13 +756,21 @@
 			}
 
 			case 'break': {
+				let val: Value | undefined;
+				if (node.expr != null) {
+					const valueOrControl = await this._eval(node.expr, scope, callStack);
+					if (isControl(valueOrControl)) {
+						return valueOrControl;
+					}
+					val = valueOrControl;
+				}
 				this.log('block:break', { scope: scope.name });
-				return BREAK();
+				return BREAK(node.label, val);
 			}
 
 			case 'continue': {
 				this.log('block:continue', { scope: scope.name });
-				return CONTINUE();
+				return CONTINUE(node.label);
 			}
 
 			case 'ns': {
@@ -910,7 +946,7 @@
 	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/node.ts

@@ -73,13 +73,15 @@ export type Return = NodeBase & {
 
 export type Each = NodeBase & {
 	type: 'each'; // each文
+	label?: string; // ラベル
 	var: Expression; // イテレータ宣言
 	items: Expression; // 配列
 	for: Statement | Expression; // 本体処理
 };
 
 export type For = NodeBase & {
 	type: 'for'; // for文
+	label?: string; // ラベル
 	var?: string; // イテレータ変数名
 	from?: Expression; // 開始値
 	to?: Expression; // 終値
@@ -89,15 +91,19 @@ export type For = NodeBase & {
 
 export type Loop = NodeBase & {
 	type: 'loop'; // loop文
+	label?: string; // ラベル
 	statements: (Statement | Expression)[]; // 処理
 };
 
 export type Break = NodeBase & {
 	type: 'break'; // break文
+	label?: string; // ラベル
+	expr?: Expression; // 式
 };
 
 export type Continue = NodeBase & {
 	type: 'continue'; // continue文
+	label?: string; // ラベル
 };
 
 export type AddAssign = NodeBase & {
@@ -265,6 +271,7 @@ export type Or = NodeBase & {
 
 export type If = NodeBase & {
 	type: 'if'; // if式
+	label?: string; // ラベル
 	cond: Expression; // 条件式
 	then: Statement | Expression; // then節
 	elseif: {
@@ -289,6 +296,7 @@ export type Fn = NodeBase & {
 
 export type Match = NodeBase & {
 	type: 'match'; // パターンマッチ
+	label?: string; // ラベル
 	about: Expression; // 対象
 	qs: {
 		q: Expression; // 条件
@@ -299,6 +307,7 @@ export type Match = NodeBase & {
 
 export type Block = NodeBase & {
 	type: 'block'; // ブロックまたはeval式
+	label?: string; // ラベル
 	statements: (Statement | Expression)[]; // 処理
 };