带亚型的角6捕捉误差

我正在开发一个与一些rest服务通信的angular 6应用程序。所有rest服务的响应都包装在如下对象中:

{
   error: false,
   message: '',
   status: 200,
   value: {}
}

value属性包含获取的数据,可以是任何内容。

我用这个类将这个结构重复为typescript

export class BaseRestResponse<T> {

  private _error: number;
  private _message: string;
  private _status: number;
  private _value: T;

  constructor();
  constructor(error: number, message: string, status: number, value: T);
  constructor(error?: number, message?: string, status?: number, value?: T) {
    this._error = error;
    this._message = message;
    this._status = status;
    this._value = value;
  }

  get error(): number {
    return this._error;
  }

  get message(): string {
    return this._message;
  }

  get status(): number {
    return this._status;
  }

  get value(): T {
    return this._value;
  }
}

我有一个基本服务,其中包含一些共享数据和用来处理http错误的函数,以及传递给rxjs catcherror的函数

import { HttpClient, HttpHeaders } from '@angular/common/http';
import { Observable, of } from 'rxjs';
import { BaseRestResponse } from './base.rest.response';

const httpOptions = {
  headers: new HttpHeaders({'Content-Type': 'application/json'})
};

export abstract class BaseService {

  baseUrl = 'http://localhost:8080/xxx';

  constructor(protected http: HttpClient) {
    this.http = http;
  }

  /**
   * @param operation 
   * @param result 
   * @returns {(error:any)=>Observable<T>}
   */
  public handleHttpError<T>(operation = 'operation', result?: T) {
    return (error: any): Observable<T> => {

        return of(result as T);
    };
  }
}

然后我有一个产品服务扩展我的基本服务,如下所示:

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable, of } from 'rxjs';
import { catchError, tap } from 'rxjs/operators';
import { BaseService } from './base.service';
import { Product } from './product/product';
import { BaseRestResponse } from './base.rest.response'

const LOCAL_URL = '/product/find';

@Injectable({
  providedIn: 'root'
})
export class ProductService extends BaseService {

  private url: string;

  constructor(http: HttpClient) {
    super(http);
    this.url = this.baseUrl + LOCAL_URL;
  }

  getAll(): Observable<Product[]> {
    let resp = new BaseRestResponse<Product[]>(this.http.get<Product[]>(this.url).pipe(
      catchError(this.handleHttpError('getAll', BaseRestResponse<Product[]>)) // this line fails to compile
    ));
    return resp;
  }

}

但我有个错误:

src/app/product.service.ts(25,76)中有错误:错误ts1005:'(应为')。 src/app/product.service.ts(26,7):应为错误ts1005:“)”。

我想做的是得到一个广义handlehttperror函数,它可以根据需要返回一个baseresponse,但是我不知道如何解决这个问题