DOM 解析、结构化文档底层遍历
作为一名开发人员，我确信我并不孤单，我总是很好奇了解“幕后”是什么。对我来说，DOM 解析器是这种好奇心的榜首之一。我们都知道著名帖子 。出于暂时的需要和好奇，我什至还编写了一些“O RLY？”。
然而，我与幕后人物见面的需求仍未得到满足。 DOM 解析器或任何结构化文档解析器如何解析文档？就我的中级 Web 应用程序开发人员的理解而言，它是递归字符串解析和状态保持逻辑的组合，与我自己的黑客尝试不同。
魔术师永远不应该泄露他们的秘密，但说真的，他把兔子藏在哪里了？
As a developer, and I'm certain I'm far from alone here, I'm always curious to understand what's "under the hood". DOM parsers are one of the list-toppers of this curiosity for me. We all know the famous post. I have even hacked together a bit of an "O RLY?", out of both temporary necessity and curiosity.
However my need to meet the man-behind-the-curtain remains unmet. How do DOM parsers, or any structured document parsers for that matter, parse documents? As far as my intermediate web application developer understanding can muster, it's a combination of recursive string parsing and state-keeping logic, not unlike my own hackish attempt.
Magicians should never reveal their secrets, but seriously, where is he hiding the rabbit?
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有一个完善的解析理论，以及无数的工具来支持它。一般来说，您一次查看每个字符，然后决定您迄今为止创建的字符何时构成一个令牌。然后，您查看这一系列标记，并决定标记序列何时构成更高级别的语法结构——在本例中为 HTML 元素。当您识别结构时，您会构建一棵节点树来表示它们——在本例中为 DOM 树。
那么您熟悉上下文无关语法以及编译器-编译器（如 yacc、bison 及其更现代的对应物）吗？如果您理解这些，DOM 解析器就不应该是一个谜。
There's a well-developed theory of parsing, and untold numbers of tools to support it. In general, you look at each character, one at a time, and decide when the characters you've made so far constitute a token. Then you look at the series of tokens, and decide when the sequence of tokens constitute a higher-level grammatical construct -- in this case, an HTML element. As you recognize constructs, you build a tree of nodes to represent them -- in this case, the DOM tree.
So are you familiar with context-free grammars, and compiler-compilers like yacc, bison, and their more modern counterparts? If you understand those, a DOM parser shouldn't be a mystery.