virt2/api/soft/CodeMirror/demo/spanaffectswrapping_shim.html

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<!doctype html>
<title>CodeMirror: Automatically derive odd wrapping behavior for your browser</title>
<meta charset="utf-8"/>
<link rel=stylesheet href="../doc/docs.css">
<div id=nav>
<a href="https://codemirror.net"><h1>CodeMirror</h1><img id=logo src="../doc/logo.png"></a>
<ul>
<li><a href="../index.html">Home</a>
<li><a href="../doc/manual.html">Manual</a>
<li><a href="https://github.com/codemirror/codemirror">Code</a>
</ul>
<ul>
<li><a class=active href="#">Automatically derive odd wrapping behavior for your browser</a>
</ul>
</div>
<article>
<h2>Automatically derive odd wrapping behavior for your browser</h2>
<p>This is a hack to automatically derive
a <code>spanAffectsWrapping</code> regexp for a browser. See the
comments above that variable
in <a href="../lib/codemirror.js"><code>lib/codemirror.js</code></a>
for some more details.</p>
<div style="white-space: pre-wrap; width: 50px;" id="area"></div>
<pre id="output"></pre>
<script id="script">
var a = document.getElementById("area"), bad = Object.create(null);
var chars = "a~`!@#$%^&*()-_=+}{[]\\|'\"/?.>,<:;", l = chars.length;
for (var x = 0; x < l; ++x) for (var y = 0; y < l; ++y) {
var s1 = "foooo" + chars.charAt(x), s2 = chars.charAt(y) + "br";
a.appendChild(document.createTextNode(s1 + s2));
var h1 = a.offsetHeight;
a.innerHTML = "";
a.appendChild(document.createElement("span")).appendChild(document.createTextNode(s1));
a.appendChild(document.createElement("span")).appendChild(document.createTextNode(s2));
if (a.offsetHeight != h1)
bad[chars.charAt(x)] = (bad[chars.charAt(x)] || "") + chars.charAt(y);
a.innerHTML = "";
}
var re = "";
function toREElt(str) {
if (str.length > 1) {
var invert = false;
if (str.length > chars.length * .6) {
invert = true;
var newStr = "";
for (var i = 0; i < l; ++i) if (str.indexOf(chars.charAt(i)) == -1) newStr += chars.charAt(i);
str = newStr;
}
str = str.replace(/[\-\.\]\"\'\\\/\^a]/g, function(orig) { return orig == "a" ? "\\w" : "\\" + orig; });
return "[" + (invert ? "^" : "") + str + "]";
} else if (str == "a") {
return "\\w";
} else if (/[?$*()+{}[\]\.|/\'\"]/.test(str)) {
return "\\" + str;
} else {
return str;
}
}
var newRE = "";
for (;;) {
var left = null;
for (var left in bad) break;
if (left == null) break;
var right = bad[left];
delete bad[left];
for (var other in bad) if (bad[other] == right) {
left += other;
delete bad[other];
}
newRE += (newRE ? "|" : "") + toREElt(left) + toREElt(right);
}
document.getElementById("output").appendChild(document.createTextNode("Your regexp is: " + (newRE || "^$")));
</script>
</article>