JS

JSON.stringfy

无法解析 JSX，原因是 JSX 对象中存在循环引用
https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
大概是 JSX 对象中引用的 context 对象，context 中肯定又有当前使用的 JSX

HTTP

“CAUTION: provisional headers are shown” in Chrome debugger

provisional headers are shown出现的情况有这么几种：

  1. 跨域，请求被浏览器拦截（此时请求状态肯定是 CORS）
  2. 请求被浏览器插件拦截
  3. 服务器出错或者超时，没有真正的返回
  4. 强缓存from disk cache或者from memory cache，此时也不会显示 (此时请求状态肯定是 200 cache)

原因 sentry 添加了额外的 request header，导致 CROS 中对不上，服务器不响应。
https://enable-cors.org/server.html
解决方式：

  1. 请求中去除该请求头
  2. 后端支持这个额外的请求头

https://docs.sentry.io/platforms/javascript/performance/instrumentation/automatic-instrumentation/#tracingorigins
You will need to configure your web server CORS to allow the sentry-trace header. The configuration might look like "Access-Control-Allow-Headers: sentry-trace", but the configuration depends on your set up. If you do not allow the sentry-trace header, the request might be blocked.
一般是在 nginx 中进行配置 Access-Control-Allow-Headers
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Headers

Node

JavaScript Heap Out Of Memory Error

该错误经常出现在 node 版本太低的环境中

  1. // 简单配置
  2. node --max-old-space-size=4096 index.js

https://blog.asayer.io/javascript-heap-out-of-memory-error
image.png

SICP

it is crucial that each function accomplishes an identifiable task that can be used as a module in defining other functions
每个函数都要完成一个可识别的任务，该任务可以用作定义其他函数的模块

when we define theisgood_enoughfunction in terms ofsquare, we are able to regard thesquarefunction as a black box.
We are not at that moment concerned with how the function computes its result, only with the fact that it computes the square.
将函数视为黑盒，不关注如何计算，只关注函数做了什么。
相比函数内部的实际计算组成，组合后的函数更像一个抽象的函数。
这样的函数生成方式是 **_f__unctional abstraction**
a function should be able to suppress detail.
函数应该能抑制细节

A parameter of a function has a very special role in the function declaration, in that it doesn’t matter what name the parameter has. Such a name is called bound, and we say that the function declaration binds its parameters. If a name is not bound, we say that it is free.
函数与它的参数绑定

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/name#bound_function_names 这里记录一下 MDN 中函数 bound 的一些内容，与这里的内容类似，但完全不想干 image.png

The set of expressions for which a binding declares a name is called the scope _of that name.
Any matching pair of braces designates a block_, and declarations inside the block are local to the block.
大括号代表块，块内声明只在块内生效
Since x is bound in the declaration of sqrt, the functions is_good_enough, improve, and sqrt_iter, which are declared internally to sqrt, are in the scope of x. Thus, it is not necessary to pass x explicitly to each of these functions. Instead, we allow x to be a free name in the internal declarations,Then x gets its value from the argument with which the enclosing function sqrt is called. This discipline is called lexical scoping
词法作用域相当于一种准则或纪律，也就是某个变量声明在它当前的作用域中都是有效的，即使作用域中还有作用域，无需传递，已可取值。

We will use block structure extensively to help us break up large programs into tractable pieces.
广泛使用块结构帮助我们将大型程序分解成易于处理的部分