Method __eval

src/interpreter/index.ts:474–1008

(node: Ast.Node, scope: Scope, callStack: readonly CallInfo[])

	@autobind
	private async __eval(node: Ast.Node, scope: Scope, callStack: readonly CallInfo[]): Promise<Value | Control> {
		if (this.stop) return NULL;
		if (this.pausing) await this.pausing.promise;
		// irqRateが小数の場合は不等間隔になる
		if (this.irqRate !== 0 && this.stepCount % this.irqRate >= this.irqRate - 1) {
			await this.irqSleep();
		}
		this.stepCount++;
		if (this.opts.maxStep && this.stepCount > this.opts.maxStep) {
			throw new AiScriptRuntimeError('max step exceeded');
		}

		switch (node.type) {
			case 'call': {
				const callee = await this._eval(node.target, scope, callStack);
				if (isControl(callee)) {
					return callee;
				}
				assertFunction(callee);
				const args = [];
				for (const expr of node.args) {
					const arg = await this._eval(expr, scope, callStack);
					if (isControl(arg)) {
						return arg;
					}
					args.push(arg);
				}
				return this._fn(callee, args, callStack, node.loc.start);
			}

			case 'if': {
				const cond = await this._eval(node.cond, scope, callStack);
				if (isControl(cond)) {
					return cond;
				}
				assertBoolean(cond);
				if (cond.value) {
					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);
					if (isControl(cond)) {
						return cond;
					}
					assertBoolean(cond);
					if (cond.value) {
						return unWrapLabeledBreak(await this._evalClause(elseif.then, scope, callStack), node.label);
					}
				}
				if (node.else) {
					return unWrapLabeledBreak(await this._evalClause(node.else, scope, callStack), node.label);
				}
				return NULL;
			}

			case 'match': {
				const about = await this._eval(node.about, scope, callStack);
				if (isControl(about)) {