patch SingleOperator in CodeMirror2

IPython/frontend/html/notebook/static/codemirror/mode/python/python.js

@@ -5,7 +5,10 CodeMirror.defineMode("python", function(conf, parserConf) {
         return new RegExp("^((" + words.join(")|(") + "))\\b");
     }
     
-    var singleOperators = new RegExp("^[\\+\\-\\*/%&|\\^~<>!]");
+    // IPython-specific changes: add '?' as recognized character.
+    var singleOperators = new RegExp("^[\\+\\-\\*/%&|\\^~<>!\\?]");
+    // End IPython changes.
+
     var singleDelimiters = new RegExp('^[\\(\\)\\[\\]\\{\\}@,:`=;\\.]');
     var doubleOperators = new RegExp("^((==)|(!=)|(<=)|(>=)|(<>)|(<<)|(>>)|(//)|(\\*\\*))");
     var doubleDelimiters = new RegExp("^((\\+=)|(\\-=)|(\\*=)|(%=)|(/=)|(&=)|(\\|=)|(\\^=))");