PureHTML.TreeBuilder.Modes.InHead (PureHTML v0.5.0)

HTML5 "in head" insertion mode.

This mode handles content inside the <head> element.

Per HTML5 spec:

Whitespace: Insert the character
Comment: Insert a comment
DOCTYPE: Parse error, ignore
<html> start tag: Process using "in body" rules
<base>, <basefont>, <bgsound>, <link>, <meta>: Insert void element
<title>: generic RCDATA element parsing
<noscript> (scripting on), <noframes>, <style>: generic raw text element parsing
<noscript> (scripting off): insert, switch to "in head noscript"
<script>: insert, switch the tokenizer to script data, switch to "text"
<template>: insert, marker, frameset-ok "not ok", push "in template"
</head>: pop the current node, switch to "after head"
</body>, </html>, </br>: Act as "anything else"
</template>: pop through the template, clear formatting to the marker, pop the template insertion mode, reset the insertion mode
<head>: Parse error, ignore
Any other end tag: Parse error, ignore
Anything else: pop the current node, switch to "after head", reprocess