--- a/coffee/rivets.coffee	Tue Mar 22 13:33:56 2016 +0800
+++ b/coffee/rivets.coffee	Tue Mar 22 15:05:34 2016 +0800
@@ -13,7 +13,7 @@
 
 
 rivets.formatters['first-letter'] = (value) ->
-  if value? then value.charAt(0) else ' '
+  value?.charAt?(0) ? ' '
 
 
 rivets.formatters['only'] = (value, allowed...) ->

--- a/js/rivets.js	Tue Mar 22 13:33:56 2016 +0800
+++ b/js/rivets.js	Tue Mar 22 15:05:34 2016 +0800
@@ -19,11 +19,8 @@
   };
 
   rivets.formatters['first-letter'] = function(value) {
-    if (value != null) {
-      return value.charAt(0);
-    } else {
-      return ' ';
-    }
+    var ref;
+    return (ref = value != null ? typeof value.charAt === "function" ? value.charAt(0) : void 0 : void 0) != null ? ref : ' ';
   };
 
   rivets.formatters['only'] = function() {

--- a/js/rivets.js.map	Tue Mar 22 13:33:56 2016 +0800
+++ b/js/rivets.js.map	Tue Mar 22 15:05:34 2016 +0800
@@ -6,5 +6,5 @@
     "coffee/rivets.coffee"
   ],
   "names": [],
-  "mappings": ";AAAA;AAAA,MAAA;;;EAAA,MAAM,CAAC,QAAS,CAAA,GAAA,CAAhB,GACE;IAAA,OAAA,EAAS,SAAC,GAAD,EAAM,OAAN,EAAe,QAAf;aACP,GAAG,CAAC,EAAJ,CAAO,SAAA,GAAY,OAAnB,EAA4B,QAA5B;IADO,CAAT;IAGA,SAAA,EAAW,SAAC,GAAD,EAAM,OAAN,EAAe,QAAf;aACT,GAAG,CAAC,GAAJ,CAAQ,SAAA,GAAY,OAApB,EAA6B,QAA7B;IADS,CAHX;IAMA,GAAA,EAAK,SAAC,GAAD,EAAM,OAAN;aACH,GAAG,CAAC,GAAJ,CAAQ,OAAR;IADG,CANL;IASA,GAAA,EAAK,SAAC,GAAD,EAAM,OAAN,EAAe,KAAf;aACH,GAAG,CAAC,GAAJ,CAAQ,OAAR,EAAiB,KAAjB;IADG,CATL;;;EAaF,MAAM,CAAC,UAAW,CAAA,cAAA,CAAlB,GAAoC,SAAC,KAAD;IAClC,IAAG,aAAH;aAAe,KAAK,CAAC,MAAN,CAAa,CAAb,EAAf;KAAA,MAAA;aAAoC,IAApC;;EADkC;;EAIpC,MAAM,CAAC,UAAW,CAAA,MAAA,CAAlB,GAA4B,SAAA;AAC1B,QAAA;IAD2B,sBAAO;IAClC,IAAG,aAAS,OAAT,EAAA,KAAA,MAAH;aAAyB,MAAzB;KAAA,MAAA;aAAoC,GAApC;;EAD0B;;EAI5B,MAAM,CAAC,UAAW,CAAA,IAAA,CAAlB,GAA0B,SAAC,CAAD,EAAI,CAAJ;WACxB,CAAA,KAAK;EADmB;;EAI1B,MAAM,CAAC,UAAW,CAAA,aAAA,CAAlB,GAAmC,SAAC,KAAD,EAAQ,MAAR;IACjC,IAAG,aAAH;aAAe,KAAK,CAAC,MAAN,CAAa,MAAb,EAAf;KAAA,MAAA;aAAyC,GAAzC;;EADiC;;EAInC,MAAM,CAAC,UAAW,CAAA,UAAA,CAAlB,GAAgC,SAAC,KAAD;IAC9B,IAAG,aAAH;aAAe,KAAK,CAAC,WAAN,CAAA,EAAf;KAAA,MAAA;aAAwC,GAAxC;;EAD8B;;EAIhC,MAAM,CAAC,UAAW,CAAA,UAAA,CAAlB,GAAgC,SAAC,KAAD;IAC9B,IAAG,aAAH;aAAe,KAAK,CAAC,OAAN,CAAA,EAAf;KAAA,MAAA;aAAoC,GAApC;;EAD8B;AAlChC"
+  "mappings": ";AAAA;AAAA,MAAA;;;EAAA,MAAM,CAAC,QAAS,CAAA,GAAA,CAAhB,GACE;IAAA,OAAA,EAAS,SAAC,GAAD,EAAM,OAAN,EAAe,QAAf;aACP,GAAG,CAAC,EAAJ,CAAO,SAAA,GAAY,OAAnB,EAA4B,QAA5B;IADO,CAAT;IAGA,SAAA,EAAW,SAAC,GAAD,EAAM,OAAN,EAAe,QAAf;aACT,GAAG,CAAC,GAAJ,CAAQ,SAAA,GAAY,OAApB,EAA6B,QAA7B;IADS,CAHX;IAMA,GAAA,EAAK,SAAC,GAAD,EAAM,OAAN;aACH,GAAG,CAAC,GAAJ,CAAQ,OAAR;IADG,CANL;IASA,GAAA,EAAK,SAAC,GAAD,EAAM,OAAN,EAAe,KAAf;aACH,GAAG,CAAC,GAAJ,CAAQ,OAAR,EAAiB,KAAjB;IADG,CATL;;;EAaF,MAAM,CAAC,UAAW,CAAA,cAAA,CAAlB,GAAoC,SAAC,KAAD;AAClC,QAAA;0HAAoB;EADc;;EAIpC,MAAM,CAAC,UAAW,CAAA,MAAA,CAAlB,GAA4B,SAAA;AAC1B,QAAA;IAD2B,sBAAO;IAClC,IAAG,aAAS,OAAT,EAAA,KAAA,MAAH;aAAyB,MAAzB;KAAA,MAAA;aAAoC,GAApC;;EAD0B;;EAI5B,MAAM,CAAC,UAAW,CAAA,IAAA,CAAlB,GAA0B,SAAC,CAAD,EAAI,CAAJ;WACxB,CAAA,KAAK;EADmB;;EAI1B,MAAM,CAAC,UAAW,CAAA,aAAA,CAAlB,GAAmC,SAAC,KAAD,EAAQ,MAAR;IACjC,IAAG,aAAH;aAAe,KAAK,CAAC,MAAN,CAAa,MAAb,EAAf;KAAA,MAAA;aAAyC,GAAzC;;EADiC;;EAInC,MAAM,CAAC,UAAW,CAAA,UAAA,CAAlB,GAAgC,SAAC,KAAD;IAC9B,IAAG,aAAH;aAAe,KAAK,CAAC,WAAN,CAAA,EAAf;KAAA,MAAA;aAAwC,GAAxC;;EAD8B;;EAIhC,MAAM,CAAC,UAAW,CAAA,UAAA,CAAlB,GAAgC,SAAC,KAAD;IAC9B,IAAG,aAAH;aAAe,KAAK,CAAC,OAAN,CAAA,EAAf;KAAA,MAAA;aAAoC,GAApC;;EAD8B;AAlChC"
 }
\ No newline at end of file