fix: ジャンプ文の挙動を変更 (#844)

* return,break,continueをValueと別の扱いにする

* 配列や引数で最初にreturnなどが出た時点でリターン

* 不正な位置のreturn文などを文法エラーに

* テストの追加と実装の修正

* APIレポートの更新

* break,continueがループ内に見えても関数がより内側なら文法エラー

* CHANGELOG

* テンプレートリテラル内returnテスト

* Control系の型や関数の秘匿と名前変更

* 使用していない関数を削除

* APIレポートの更新

* APIレポートの修正

etc/aiscript.api.md

@@ -218,9 +218,6 @@ type Bool = NodeBase & {
     value: boolean;
 };
 
-// @public (undocumented)
-const BREAK: () => Value;
-
 // @public (undocumented)
 type Break = NodeBase & {
     type: 'break';
@@ -233,9 +230,6 @@ type Call = NodeBase & {
     args: Expression[];
 };
 
-// @public (undocumented)
-const CONTINUE: () => Value;
-
 // @public (undocumented)
 type Continue = NodeBase & {
     type: 'continue';
@@ -634,9 +628,6 @@ type Rem = NodeBase & {
 // @public (undocumented)
 function reprValue(value: Value, literalLike?: boolean, processedObjects?: Set<object>): string;
 
-// @public (undocumented)
-const RETURN: (v: VReturn["value"]) => Value;
-
 // @public (undocumented)
 type Return = NodeBase & {
     type: 'return';
@@ -710,9 +701,6 @@ const TRUE: {
 // @public (undocumented)
 type TypeSource = NamedTypeSource | FnTypeSource;
 
-// @public (undocumented)
-const unWrapRet: (v: Value) => Value;
-
 declare namespace utils {
     export {
         expectAny,
@@ -746,7 +734,7 @@ function valToJs(val: Value): JsValue;
 function valToString(val: Value, simple?: boolean): string;
 
 // @public (undocumented)
-type Value = (VNull | VBool | VNum | VStr | VArr | VObj | VFn | VReturn | VBreak | VContinue | VError) & Attr_2;
+type Value = (VNull | VBool | VNum | VStr | VArr | VObj | VFn | VError) & Attr_2;
 
 declare namespace values {
     export {
@@ -760,9 +748,6 @@ declare namespace values {
         VUserFn,
         VFnParam,
         VNativeFn,
-        VReturn,
-        VBreak,
-        VContinue,
         VError,
         Attr_2 as Attr,
         Value,
@@ -776,10 +761,6 @@ declare namespace values {
         ARR,
         FN,
         FN_NATIVE,
-        RETURN,
-        BREAK,
-        CONTINUE,
-        unWrapRet,
         ERROR
     }
 }
@@ -797,18 +778,6 @@ type VBool = {
     value: boolean;
 };
 
-// @public (undocumented)
-type VBreak = {
-    type: 'break';
-    value: null;
-};
-
-// @public (undocumented)
-type VContinue = {
-    type: 'continue';
-    value: null;
-};
-
 // @public (undocumented)
 type VError = {
     type: 'error';
@@ -857,12 +826,6 @@ type VObj = {
     value: Map<string, Value>;
 };
 
-// @public (undocumented)
-type VReturn = {
-    type: 'return';
-    value: Value;
-};
-
 // @public (undocumented)
 type VStr = {
     type: 'str';
@@ -882,7 +845,7 @@ type VUserFn = VFnBase & {
 
 // Warnings were encountered during analysis:
 //
-// src/interpreter/index.ts:47:4 - (ae-forgotten-export) The symbol "LogObject" needs to be exported by the entry point index.d.ts
+// src/interpreter/index.ts:48:4 - (ae-forgotten-export) The symbol "LogObject" needs to be exported by the entry point index.d.ts
 // src/interpreter/value.ts:47:2 - (ae-forgotten-export) The symbol "Type" needs to be exported by the entry point index.d.ts
 
 // (No @packageDocumentation comment for this package)

src/interpreter/control.ts

@@ -0,0 +1,82 @@
+import { AiScriptRuntimeError } from '../error.js';
+import type { Reference } from './reference.js';
+import type { Value } from './value.js';
+
+export type CReturn = {
+	type: 'return';
+	value: Value;
+};
+
+export type CBreak = {
+	type: 'break';
+	value: null;
+};
+
+export type CContinue = {
+	type: 'continue';
+	value: null;
+};
+
+export type Control = CReturn | CBreak | CContinue;
+
+// Return文で値が返されたことを示すためのラッパー
+export const RETURN = (v: CReturn['value']): CReturn => ({
+	type: 'return' as const,
+	value: v,
+});
+
+export const BREAK = (): CBreak => ({
+	type: 'break' as const,
+	value: null,
+});
+
+export const CONTINUE = (): CContinue => ({
+	type: 'continue' as const,
+	value: null,
+});
+
+export function unWrapRet(v: Value | Control): Value {
+	switch (v.type) {
+		case 'return':
+			return v.value;
+		default: {
+			assertValue(v);
+			return v;
+		}
+	}
+}
+
+export function assertValue(v: Value | Control): asserts v is Value {
+	switch (v.type) {
+		case 'return':
+			throw new AiScriptRuntimeError('Invalid return');
+		case 'break':
+			throw new AiScriptRuntimeError('Invalid break');
+		case 'continue':
+			throw new AiScriptRuntimeError('Invalid continue');
+		default:
+			v satisfies Value;
+	}
+}
+
+export function isControl(v: Value | Control | Reference): v is Control {
+	switch (v.type) {
+		case 'null':
+		case 'bool':
+		case 'num':
+		case 'str':
+		case 'arr':
+		case 'obj':
+		case 'fn':
+		case 'error':
+		case 'reference':
+			return false;
+		case 'return':
+		case 'break':
+		case 'continue':
+			return true;
+	}
+	// exhaustive check
+	v satisfies never;
+	throw new TypeError('expected value or control');
+}