Move yoga docs into docs folder on master branch

Summary: Move yoga docs into master branch so that pull requests are able to include doc updates as part of other changes.

Reviewed By: JoelMarcey

Differential Revision: D4365700

fbshipit-source-id: 2f46a88974104c454c00bcdf1257abb5c4075a68

docs/_includes/katex_render.html

@@ -0,0 +1,210 @@
+<script type="text/javascript">
+/* global katex */
+
+var findEndOfMath = function(delimiter, text, startIndex) {
+    // Adapted from
+    // https://github.com/Khan/perseus/blob/master/src/perseus-markdown.jsx
+    var index = startIndex;
+    var braceLevel = 0;
+
+    var delimLength = delimiter.length;
+
+    while (index < text.length) {
+        var character = text[index];
+
+        if (braceLevel <= 0 &&
+            text.slice(index, index + delimLength) === delimiter) {
+            return index;
+        } else if (character === "\\") {
+            index++;
+        } else if (character === "{") {
+            braceLevel++;
+        } else if (character === "}") {
+            braceLevel--;
+        }
+
+        index++;
+    }
+
+    return -1;
+};
+
+var splitAtDelimiters = function(startData, leftDelim, rightDelim, display) {
+    var finalData = [];
+
+    for (var i = 0; i < startData.length; i++) {
+        if (startData[i].type === "text") {
+            var text = startData[i].data;
+
+            var lookingForLeft = true;
+            var currIndex = 0;
+            var nextIndex;
+
+            nextIndex = text.indexOf(leftDelim);
+            if (nextIndex !== -1) {
+                currIndex = nextIndex;
+                finalData.push({
+                    type: "text",
+                    data: text.slice(0, currIndex)
+                });
+                lookingForLeft = false;
+            }
+
+            while (true) {
+                if (lookingForLeft) {
+                    nextIndex = text.indexOf(leftDelim, currIndex);
+                    if (nextIndex === -1) {
+                        break;
+                    }
+
+                    finalData.push({
+                        type: "text",
+                        data: text.slice(currIndex, nextIndex)
+                    });
+
+                    currIndex = nextIndex;
+                } else {
+                    nextIndex = findEndOfMath(
+                        rightDelim,
+                        text,
+                        currIndex + leftDelim.length);
+                    if (nextIndex === -1) {
+                        break;
+                    }
+
+                    finalData.push({
+                        type: "math",
+                        data: text.slice(
+                            currIndex + leftDelim.length,
+                            nextIndex),
+                        rawData: text.slice(
+                            currIndex,
+                            nextIndex + rightDelim.length),
+                        display: display
+                    });
+
+                    currIndex = nextIndex + rightDelim.length;
+                }
+
+                lookingForLeft = !lookingForLeft;
+            }
+
+            finalData.push({
+                type: "text",
+                data: text.slice(currIndex)
+            });
+        } else {
+            finalData.push(startData[i]);
+        }
+    }
+
+    return finalData;
+};
+
+var splitWithDelimiters = function(text, delimiters) {
+    var data = [{type: "text", data: text}];
+    for (var i = 0; i < delimiters.length; i++) {
+        var delimiter = delimiters[i];
+        data = splitAtDelimiters(
+            data, delimiter.left, delimiter.right,
+            delimiter.display || false);
+    }
+    return data;
+};
+
+var renderMathInText = function(text, delimiters) {
+    var data = splitWithDelimiters(text, delimiters);
+
+    var fragment = document.createDocumentFragment();
+
+    for (var i = 0; i < data.length; i++) {
+        if (data[i].type === "text") {
+            fragment.appendChild(document.createTextNode(data[i].data));
+        } else {
+            var span = document.createElement("span");
+            var math = data[i].data;
+            try {
+                katex.render(math, span, {
+                    displayMode: data[i].display
+                });
+            } catch (e) {
+                if (!(e instanceof katex.ParseError)) {
+                    throw e;
+                }
+                console.error(
+                    "KaTeX auto-render: Failed to parse `" + data[i].data +
+                    "` with ",
+                    e
+                );
+                fragment.appendChild(document.createTextNode(data[i].rawData));
+                continue;
+            }
+            fragment.appendChild(span);
+        }
+    }
+
+    return fragment;
+};
+
+var renderElem = function(elem, delimiters, ignoredTags) {
+    for (var i = 0; i < elem.childNodes.length; i++) {
+        var childNode = elem.childNodes[i];
+        if (childNode.nodeType === 3) {
+            // Text node
+            var frag = renderMathInText(childNode.textContent, delimiters);
+            i += frag.childNodes.length - 1;
+            elem.replaceChild(frag, childNode);
+        } else if (childNode.nodeType === 1) {
+            // Element node
+            var shouldRender = ignoredTags.indexOf(
+                childNode.nodeName.toLowerCase()) === -1;
+
+            if (shouldRender) {
+                renderElem(childNode, delimiters, ignoredTags);
+            }
+        }
+        // Otherwise, it's something else, and ignore it.
+    }
+};
+
+var defaultOptions = {
+    delimiters: [
+        {left: "$$", right: "$$", display: true},
+        {left: "\\[", right: "\\]", display: true},
+        {left: "\\(", right: "\\)", display: false}
+        // LaTeX uses this, but it ruins the display of normal `$` in text:
+        // {left: "$", right: "$", display: false}
+    ],
+
+    ignoredTags: [
+        "script", "noscript", "style", "textarea", "pre", "code"
+    ]
+};
+
+var extend = function(obj) {
+    // Adapted from underscore.js' `_.extend`. See LICENSE.txt for license.
+    var source, prop;
+    for (var i = 1, length = arguments.length; i < length; i++) {
+        source = arguments[i];
+        for (prop in source) {
+            if (Object.prototype.hasOwnProperty.call(source, prop)) {
+                obj[prop] = source[prop];
+            }
+        }
+    }
+    return obj;
+};
+
+var renderMathInElement = function(elem, options) {
+    if (!elem) {
+        throw new Error("No element provided to render");
+    }
+
+    options = extend({}, defaultOptions, options);
+
+    renderElem(elem, options.delimiters, options.ignoredTags);
+};
+
+renderMathInElement(document.body);
+
+</script>