Support \bgroup and \egroup

src/macros.js

@@ -8,6 +8,13 @@ function defineMacro(name, body) {
     module.exports[name] = body;
 }
 
+//////////////////////////////////////////////////////////////////////
+// basics
+defineMacro("\\bgroup", "{");
+defineMacro("\\egroup", "}");
+defineMacro("\\begingroup", "{");
+defineMacro("\\endgroup", "}");
+
 //////////////////////////////////////////////////////////////////////
 // amsmath.sty
 

test/screenshotter/ss_data.js

@@ -26,5 +26,8 @@ for (var key in dict) {
         }
     });
     itm.query = querystring.stringify(query);
+    if (itm.macros) {
+        itm.query += "&" + querystring.stringify(itm.macros);
+    }
 }
 module.exports = dict;

test/screenshotter/ss_data.yaml

@@ -74,6 +74,11 @@ Exponents: a^{a^a_a}_{a^a_a}
 FractionTest: \dfrac{a}{b}\frac{a}{b}\tfrac{a}{b}\;-\dfrac12\;1\tfrac12\;{1 \atop 2}
 Functions: \sin\cos\tan\ln\log
 GreekLetters: \alpha\beta\gamma\omega
+GroupMacros:
+    macros:
+        \startExp: e^\bgroup
+        \endExp: \egroup
+    tex: \startExp a+b\endExp
 KaTeX: \KaTeX
 Kern:
     tex: \frac{a\kern{1em}b}{c}a\kern{1em}b\kern{1ex}c\kern{-0.25em}d

test/screenshotter/test.html

@@ -47,6 +47,12 @@
       if (query["errorColor"]) {
           settings.errorColor = query["errorColor"];
       }
+      var macros = {};
+      var macroRegex = /(?:^\?|&)(?:\\|%5[Cc])([A-Za-z]+)=([^&]*)/g;
+      while ((match = macroRegex.exec(window.location.search)) !== null) {
+          settings.macros = macros;
+          macros["\\" + match[1]] = decodeURIComponent(match[2]);
+      }
 
       katex.render(query["tex"], mathNode, settings);
       document.getElementById("pre").innerHTML = query["pre"] || "";