Refactor most of the javascript

Summary: Move MJLite into its own file, make a module. Now includes underscore.

Test Plan: Make sure it still parses stuff.

Reviewers: spicyj

Reviewed By: spicyj

CC: divad12

Differential Revision: http://phabricator.benalpert.com/D32

MJLite.js

@@ -0,0 +1,108 @@
+var MJLite = (function() {
+
+    var buildExpression = function(expression) {
+        return _.map(expression, function(ex, i) {
+            var prev = i > 0 ? expression[i-1] : null;
+
+            return buildGroup(ex, prev);
+        });
+    };
+
+    var makeSpan = function(className, children) {
+        var span = document.createElement("span");
+        span.className = className;
+
+        if (_.isArray(children)) {
+            _.each(children, function(v) {
+                span.appendChild(v);
+            });
+        } else if (children) {
+            span.appendChild(children);
+        }
+
+        return span;
+    };
+
+    var buildGroup = function(group, prev) {
+        if (group.type === "ord") {
+            return makeSpan("mord", mathit(group.value));
+        } else if (group.type === "bin") {
+            var className = "mbin";
+            if (prev == null || prev.type === "bin" || prev.type === "open") {
+                group.type = "ord";
+                elem.className = "mord";
+            }
+            return makeSpan(className, mathit(group.value));
+        } else if (group.type === "sup") {
+            var sup = makeSpan("msup", buildExpression(group.value.sup));
+            return makeSpan("mord", buildExpression(group.value.base).concat(sup));
+        } else if (group.type === "sub") {
+            var sub = makeSpan("msub", buildExpression(group.value.sub, sub));
+            return makeSpan("mord", buildExpression(group.value.base, elem).concat(sub));
+        } else if (group.type === "supsub") {
+            var sup = makeSpan("msup", buildExpression(group.value.sup, sup));
+            var sub = makeSpan("msub", buildExpression(group.value.sub, sub));
+
+            var supsub = makeSpan("msupsub", [sup, sub]);
+
+            return makeSpan("mord", buildExpression(group.value.base, elem).concat(supsub));
+        } else if (group.type === "open") {
+            return makeSpan("mopen", mathit(group.value));
+        } else if (group.type === "close") {
+            return makeSpan("mclose", mathit(group.value));
+        } else if (group.type === "cdot") {
+            return makeSpan("mbin", textit("cdot"));
+        } else if (group.type === "frac") {
+            var numer = makeSpan("mfracnum", buildExpression(group.value.numer, numer));
+            var mid = makeSpan("mfracmid", makeSpan());
+            var denom = makeSpan("mfracden", buildExpression(group.value.denom, denom));
+
+            return makeSpan("mord mfrac", [numer, mid, denom]);
+        } else {
+            console.log("Unknown type:", group.type);
+        }
+    };
+
+    var charLookup = {
+        '*': '\u2217',
+        '-': '\u2212',
+        'cdot': '\u22C5'
+    };
+
+    var textit = function(value) {
+        if (value in charLookup) {
+            value = charLookup[value];
+        }
+        return document.createTextNode(value);
+    };
+
+    var mathit = function(value) {
+        var text = textit(value);
+
+        if (/[a-zA-Z]/.test(value)) {
+            return makeSpan("mathit", text);
+        } else {
+            return text;
+        }
+    };
+
+    var clearNode = function(node) {
+        var children = node.childNodes;
+        for (var i = children.length - 1; i >= 0; i--) {
+            node.removeChild(children[i]);
+        }
+    };
+
+    var process = function(toParse, baseElem) {
+        var tree = parser.parse(toParse);
+        clearNode(baseElem);
+        _.each(buildExpression(tree), function(elem) {
+            baseElem.appendChild(elem);
+        });
+    };
+
+    return {
+        process: process
+    };
+
+})();