try catches in closures

Author: calvinmetcalf

lib/loader.js

@@ -110,18 +110,20 @@ function logloads(loads) {
     var traceur;
 
     var defineProperty;
-    try {
-      if (!!Object.defineProperty({}, 'a', {})) {
-        defineProperty = Object.defineProperty;
-      }
-    } catch (e) {
-      defineProperty = function (obj, prop, opt) {
-        try {
-          obj[prop] = opt.value || opt.get.call(obj);
+    (function () {
+      try {
+        if (!!Object.defineProperty({}, 'a', {})) {
+          defineProperty = Object.defineProperty;
+        }
+      } catch (e) {
+        defineProperty = function (obj, prop, opt) {
+          try {
+            obj[prop] = opt.value || opt.get.call(obj);
+          }
+          catch(e) {}
         }
-        catch(e) {}
       }
-    }
+    }());
 
     console.assert = console.assert || function() {};
 
@@ -190,64 +192,66 @@ function logloads(loads) {
 
       console.assert(load.source, 'Non-empty source');
 
-      var depsList;
-      try {
-        var parser = new traceur.syntax.Parser(new traceur.syntax.SourceFile(load.address, load.source));
-        var body = parser.parseModule();
+      var depsList, curRegister, curSystem, oldSourceMaps, oldModules;
+      (function () {
+        try {
+          var parser = new traceur.syntax.Parser(new traceur.syntax.SourceFile(load.address, load.source));
+          var body = parser.parseModule();
 
-        load.kind = 'declarative';
-        depsList = getImports(body);
+          load.kind = 'declarative';
+          depsList = getImports(body);
 
-        var oldSourceMaps = traceur.options.sourceMaps;
-        var oldModules = traceur.options.modules;
+          oldSourceMaps = traceur.options.sourceMaps;
+          oldModules = traceur.options.modules;
 
-        traceur.options.sourceMaps = true;
-        traceur.options.modules = 'instantiate';
+          traceur.options.sourceMaps = true;
+          traceur.options.modules = 'instantiate';
 
-        var reporter = new traceur.util.ErrorReporter();
+          var reporter = new traceur.util.ErrorReporter();
 
-        reporter.reportMessageInternal = function(location, kind, format, args) {
-          throw new SyntaxError(kind, location.start && location.start.line_, location.start && location.start.column_);
-        }
+          reporter.reportMessageInternal = function(location, kind, format, args) {
+            throw new SyntaxError(kind, location.start && location.start.line_, location.start && location.start.column_);
+          }
 
-        // traceur expects its version of System
-        var curSystem = __global.System;
-        __global.System = __global.traceurSystem;
+          // traceur expects its version of System
+          curSystem = __global.System;
+          __global.System = __global.traceurSystem;
 
-        var tree = (new traceur.codegeneration.module.AttachModuleNameTransformer(load.name)).transformAny(body);
-        tree = (new traceur.codegeneration.FromOptionsTransformer(reporter)).transform(tree);
+          var tree = (new traceur.codegeneration.module.AttachModuleNameTransformer(load.name)).transformAny(body);
+          tree = (new traceur.codegeneration.FromOptionsTransformer(reporter)).transform(tree);
 
-        var sourceMapGenerator = new traceur.outputgeneration.SourceMapGenerator({ file: load.address });
-        var options = { sourceMapGenerator: sourceMapGenerator };
+          var sourceMapGenerator = new traceur.outputgeneration.SourceMapGenerator({ file: load.address });
+          var options = { sourceMapGenerator: sourceMapGenerator };
 
-        var source = traceur.outputgeneration.TreeWriter.write(tree, options);
+          var source = traceur.outputgeneration.TreeWriter.write(tree, options);
 
-        if (__global.btoa)
-          source += '\n//# sourceMappingURL=data:application/json;base64,' + btoa(unescape(encodeURIComponent(options.sourceMap))) + '\n';
+          if (__global.btoa)
+            source += '\n//# sourceMappingURL=data:application/json;base64,' + btoa(unescape(encodeURIComponent(options.sourceMap))) + '\n';
 
-        // now run System.register
-        var curRegister = System.register;
+          // now run System.register
+          curRegister = System.register;
 
-        System.register = function(name, deps, declare) {
-          // store the registered declaration as load.declare
-          load.declare = typeof name == 'string' ? declare : deps;
-        }
+          System.register = function(name, deps, declare) {
+            // store the registered declaration as load.declare
+            load.declare = typeof name == 'string' ? declare : deps;
+          }
 
-        __eval(source, __global, load.name);
-      }
-      catch(e) {
-        if (e.name == 'SyntaxError' || e.name == 'TypeError')
-          e.message = 'Evaluating ' + (load.name || load.address) + '\n\t' + e.message;
-        if (curRegister)
-          System.register = curRegister;
-        if (curSystem)
-          __global.System = curSystem;
-        if (oldSourceMaps)
-          traceur.options.sourceMaps = oldSourceMaps;
-        if (oldModules)
-          traceur.options.modules = oldModules;
-        throw e;
-      }
+          __eval(source, __global, load.name);
+        }
+        catch(e) {
+          if (e.name == 'SyntaxError' || e.name == 'TypeError')
+            e.message = 'Evaluating ' + (load.name || load.address) + '\n\t' + e.message;
+          if (curRegister)
+            System.register = curRegister;
+          if (curSystem)
+            __global.System = curSystem;
+          if (oldSourceMaps)
+            traceur.options.sourceMaps = oldSourceMaps;
+          if (oldModules)
+            traceur.options.modules = oldModules;
+          throw e;
+        }
+      }());
       System.register = curRegister;
       __global.System = curSystem;
       traceur.options.sourceMaps = oldSourceMaps;