Method define

src/interpreter/index.ts:1686–1710

(scope: Scope, dest: Ast.Expression, value: Value, isMutable: boolean)

	@autobind
	private define(scope: Scope, dest: Ast.Expression, value: Value, isMutable: boolean): void {
		switch (dest.type) {
			case 'identifier': {
				scope.add(dest.name, { isMutable, value });
				break;
			}
			case 'arr': {
				assertArray(value);
				dest.value.map(
					(item, index) => this.define(scope, item, value.value[index] ?? NULL, isMutable),
				);
				break;
			}
			case 'obj': {
				assertObject(value);
				[...dest.value].map(
					([key, item]) => this.define(scope, item, value.value.get(key) ?? NULL, isMutable),
				);
				break;
			}
			default: {
				throw new AiScriptRuntimeError('The left-hand side of an definition expression must be a variable.');
			}
		}
	}

	@autobind
	private async getReference(dest: Ast.Expression, scope: Scope, callStack: readonly CallInfo[]): Promise<Reference | Control> {