雄辩的Javascript第6章中的示例6.3需要这么复杂吗？

我将添加一个免责声明，除非您熟悉，否则此上下文可能没有意义

在的在线版中，我试图理解代码示例6.3的解释

该示例专门介绍了splitparation（）函数，但是我在代码示例中添加了所有附加函数，使其在本文底部的示例中独立工作，但具体地说，我试图理解为什么作者建议千方百计寻找字符串的长度

作者建议使用A）：

var end = reduce(Math.min, text.length, map(indexOrEnd, ["*", "{"]));

var end = text.length;

为什么不直接使用B）：

var end = reduce(Math.min, text.length, map(indexOrEnd, ["*", "{"]));

var end = text.length;

我尝试过使用B），结果似乎是一样的。我可以弄清楚A）到底是怎么回事，但我不明白这样做有什么意义

这是完整的代码转储，我在底部做了一个修改，如果有人复制并粘贴它，我会将其输出：

function reduce(combine, base, array) {
  forEach(array, function (element) {
    base = combine(base, element);
  });
  return base;
}

function forEach(array, action) {
  for (var i = 0; i < array.length; i++)
    action(array[i]);
}

function map(func, array) {
  var result = [];
  forEach(array, function (element) {
    result.push(func(element));
  });
  return result;
}

function splitParagraph(text) {

    function indexOrEnd(character) {
        var index = text.indexOf(character);
        return index == -1 ? text.length : index;
    }

    function takeNormal() {
        var end = reduce(Math.min, text.length, map(indexOrEnd, ["*", "{"]));
        var part = text.slice(0, end);
        text = text.slice(end);
        return part;
    }

    function takeUpTo(character) {
        var end = text.indexOf(character, 1);
        if (end == -1)
            throw new Error("Missing closing '" + character + "'");

        var part = text.slice(1, end);
        text = text.slice(end + 1);

        return part;
    }

  var fragments = [];

  while (text != "") {
    if (text.charAt(0) == "*")
      fragments.push({type: "emphasised", content: takeUpTo("*")});
    else if (text.charAt(0) == "{")
      fragments.push({type: "footnote", content: takeUpTo("}")});
    else
      fragments.push({type: "normal", content: takeNormal()});
  }
  return fragments;
}

console.log(splitParagraph("hello world"));

function reduce（联合收割机、基地、阵列）{
forEach（数组、函数（元素）{
底座=联合收割机（底座、元件）；
});
返回基地；
}
函数forEach（数组、操作）{
对于（var i=0；i

使用方法A在出现

{

或

*

时中断字符串。因此，SplitParagation函数将中断包含这些字符的文本

i、 e

x将包含

[
  { type: "normal", content "hello boy " },
  { type: "emphasised", content "you're the best" },
  { type: "normal", content " friend " },
  { type: "footnote", content "for me" }
]

[
  { type: "normal", content "Hello boy *you're the best* friend {for me}" }
]

使用方法Bx将包含

[
  { type: "normal", content "hello boy " },
  { type: "emphasised", content "you're the best" },
  { type: "normal", content " friend " },
  { type: "footnote", content "for me" }
]

[
  { type: "normal", content "Hello boy *you're the best* friend {for me}" }
]

---

使用方法A在出现

{

或

*

时中断字符串。因此，SplitParagation函数将中断包含这些字符的文本

i、 e

x将包含

[
  { type: "normal", content "hello boy " },
  { type: "emphasised", content "you're the best" },
  { type: "normal", content " friend " },
  { type: "footnote", content "for me" }
]

[
  { type: "normal", content "Hello boy *you're the best* friend {for me}" }
]

使用方法Bx将包含

[
  { type: "normal", content "hello boy " },
  { type: "emphasised", content "you're the best" },
  { type: "normal", content " friend " },
  { type: "footnote", content "for me" }
]

[
  { type: "normal", content "Hello boy *you're the best* friend {for me}" }
]