Question

例如，如何在ATS中编写遍历给定字符串的代码，如下面的C代码所示：

while ((c = *str++) != 0) do_something(c);

Answer 1

嗯，总有一个基于组合器的解决方案：

(str).foreach()(lam(c) => do_something(c))

Answer 2

以下解决方案简单易用，并且不需要任何不安全的功能（但它确实使用了一个高级功能：索引字符串类型）。

fun
loop {n:int}(p0: string(n)): void =
if string_isnot_empty (p0) then let
  val c = (g0ofg1)(string_head(p0))
  val p0 = string_tail(p0)
in
  do_something(c); loop(p0)
end

完整代码：https://glot.io/snippets/ejpwxk2xzx

Answer 3

以下解决方案使用了UNSAFE，但它应该非常容易访问：

import { TestBed, getTestBed, async, inject } from '@angular/core/testing';
import { Headers, BaseRequestOptions, Response, HttpModule, Http, XHRBackend, RequestMethod} from '@angular/http';

import {ResponseOptions} from '@angular/http';
import {MockBackend, MockConnection} from '@angular/http/testing';
import {FooHttpService} from '../../services/foo-service.service.ts';


describe('My Service Making an Http Call', () => {

    let mockBackend: MockBackend;

    beforeEach(async(() => {
        TestBed.configureTestingModule({
            providers: [
                FooHttpService,
                MockBackend,
                BaseRequestOptions,
                {
                    provide: Http,
                    deps: [MockBackend, BaseRequestOptions],
                    useFactory:
                        (backend: XHRBackend, defaultOptions: BaseRequestOptions) => {
                            return new Http(backend, defaultOptions);
                        }
                }
            ],
            imports: [
                HttpModule
            ]
        });

        mockBackend = getTestBed().get(MockBackend);
        TestBed.compileComponents();
    }));

如何在给定字符串中构建ATS循环？

3 个答案: