Attempt to merge ords together

Summary:
Try not to waste spans by putting a bunch of numbers or letters
together into the same ord box. I don't think that this breaks any of the
current stuff.

Test Plan:
Write lots of expressions that have ords in them. Make sure that all
the reasonable ords are grouped together, and that the formatting still works.

Reviewers: spicyj

Reviewed By: spicyj

Differential Revision: http://phabricator.benalpert.com/D52

MJLite.js

@@ -30,8 +30,10 @@ var makeSpan = function(className, children) {
 };
 
 var buildGroup = function(group, prev) {
-    if (group.type === "ord") {
+    if (group.type === "mathord") {
         return makeSpan("mord", mathit(group.value));
+    } else if (group.type === "textord") {
+        return makeSpan("mord", textit(group.value));
     } else if (group.type === "bin") {
         var className = "mbin";
         if (prev == null || _.contains(["bin", "open", "rel"], prev.type)) {
@@ -123,13 +125,7 @@ var textit = function(value) {
 };
 
 var mathit = function(value) {
-    var text = textit(value);
-
-    if (/[a-zA-Z]/.test(value)) {
-        return makeSpan("mathit", text);
-    } else {
-        return text;
-    }
+    return makeSpan("mathit", textit(value));
 };
 
 var clearNode = function(node) {

lexer.js

@@ -2,7 +2,8 @@ function Lexer() {
 };
 
 var normals = [
-    [/^[/|a-zA-Z0-9.]/, 'ORD'],
+    [/^[/|0-9.]+/, 'TEXTORD'],
+    [/^[a-zA-Z]+/, 'MATHORD'],
     [/^[*+-]/, 'BIN'],
     [/^[=<>]/, 'REL'],
     [/^[,;]/, 'PUNCT'],

parser.jison

@@ -143,8 +143,10 @@ func
     ;
 
 atom
-    : 'ORD'
-        {$$ = [{type: 'ord', value: yytext}];}
+    : 'TEXTORD'
+        {$$ = [{type: 'textord', value: yytext}];}
+    | 'MATHORD'
+        {$$ = [{type: 'mathord', value: yytext}];}
     | 'BIN'
         {$$ = [{type: 'bin', value: yytext}];}
     | 'REL'