diff --git a/bin/condense b/bin/condense
index 45fde8c6..35c8032c 100755
--- a/bin/condense
+++ b/bin/condense
@@ -2,13 +2,14 @@
 
 var tern = require("../lib/tern"), condense = require("../lib/condense");
 var path = require("path"), fs = require("fs");
-require("../plugin/doc_comment");
+var disableDocComment = process.argv.indexOf("--disable-doc-comment") > -1;
+if (!disableDocComment) require("../plugin/doc_comment");
 
 var localDir = process.cwd(), ourDir = path.resolve(__dirname, "..");
 var spans = true;
 
 function usage(exit) {
-  console.error("usage: " + process.argv[1] + " [--name name] [--plugin name]* [--def name]* [+extrafile.js]* [file.js]+");
+  console.error("usage: " + process.argv[1] + " [--no-spans] [--disable-doc-comment] [--name name] [--plugin name]* [--def name]* [+extrafile.js]* [file.js]+");
   if (exit != null) process.exit(exit);
 }
 
@@ -60,6 +61,7 @@ for (var i = 2, len = process.argv.length; i < len; ++i) {
     loadDef(process.argv[++i]);
   } else if (cur == "--name" && i < len - 1) {
     name = process.argv[++i];
+  } else if (cur == "--disable-doc-comment") {
   } else if (cur == "--no-spans") {
     spans = false;
   } else if (cur.charAt(0) == "-") {
diff --git a/bin/test b/bin/test
index 72565937..3c5e4610 100755
--- a/bin/test
+++ b/bin/test
@@ -7,5 +7,6 @@ require("../test/fragments").runTests(filter);
 require("../test/condense").runTests(filter);
 require("../test/timeout").runTests(filter);
 require("../test/reload").runTests(filter);
+require("../test/def-parser").runTests(filter);
 
 process.exit(require("../test/util").hasFailed());
diff --git a/lib/condense.js b/lib/condense.js
index 9895727e..1272ff60 100644
--- a/lib/condense.js
+++ b/lib/condense.js
@@ -94,6 +94,10 @@
 
   function reach(type, path, id, state, byName) {
     var actual = type.getType(false);
+    if (!actual && type.path && type.path !== "?") {
+      state.altPaths[id] = type;
+      return;
+    }
     if (!actual) return;
     var orig = type.origin || actual.origin, relevant = false;
     if (orig) {
@@ -113,7 +117,7 @@
           state.altPaths[oldPath] = actual;
         } else data = {type: actual};
         data.span = state.getSpan(type) || (actual != type && state.isTarget(actual.origin) && state.getSpan(actual)) || data.span;
-        data.doc = type.doc || (actual != type && state.isTarget(actual.origin) && type.doc) || data.doc;
+        data.doc = type.doc || (actual != type && state.isTarget(actual.origin) && actual.doc) || data.doc;
         data.data = actual.metaData;
         data.byName = data.byName == null ? !!byName : data.byName && byName;
         state.types[newPath] = data;
@@ -129,6 +133,8 @@
 
   infer.Prim.prototype.reached = function() {return true;};
 
+  infer.UnionType.prototype.reached = function() {return true;};
+
   infer.Arr.prototype.reached = function(path, state, concrete) {
     if (!concrete) reachByName(this.getProp("<i>"), path, "<i>", state);
     return true;
@@ -226,6 +232,8 @@
     return name;
   }
 
+  infer.UnionType.prototype.typeName = function () { return this.toString(); }
+
   infer.Prim.prototype.typeName = function() { return this.name; };
 
   infer.Arr.prototype.typeName = function() {
diff --git a/lib/def.js b/lib/def.js
index 8bb83c0e..e1187030 100644
--- a/lib/def.js
+++ b/lib/def.js
@@ -76,7 +76,18 @@
       if (computeRetStart != null) fn.computeRetSource = this.spec.slice(computeRetStart, this.pos);
       return fn;
     },
+    parseUnionType: function(name, top) {
+      var types = [];
+      while (true) {
+        types.push(this.parseType());
+        if(!this.eat("|")) break;
+      }
+      return new infer.UnionType(types);
+    },
     parseType: function(name, top) {
+      if (this.eat("(")) {
+        return this.parseUnionType(name, top);
+      }
       if (this.eat("fn(")) {
         return this.parseFnType(name, top);
       } else if (this.eat("[")) {
@@ -332,6 +343,7 @@
       if (typeof inner == "string") {
         if (type) continue;
         parseType(inner, innerPath).propagate(known);
+        known.path = inner;
       } else {
         if (!isSimpleAnnotation(inner)) {
           passTwo(type, inner, innerPath);
diff --git a/lib/infer.js b/lib/infer.js
index 716fbf02..df73b543 100644
--- a/lib/infer.js
+++ b/lib/infer.js
@@ -410,6 +410,24 @@
       if (this.proto) this.proto.gatherProperties(f, depth);
     }
   });
+  
+  var UnionType = exports.UnionType = function(array) { this.value = array; }
+  UnionType.prototype = extend(Type.prototype, {
+    constructor: UnionType,
+    toString: function() {
+        var format = "(";
+        for (var i = 0; i < this.value.length; i++) {
+          format += this.value[i].getType().toString();
+          if (i < this.value.length-1 ) format += "|";
+        }
+        format += ")";
+        return format;
+    },
+    gatherProperties: function(f, depth) {
+      for (var i = 0; i < this.value.length; ++i)
+        this.value[i].gatherProperties(f, depth);
+    }
+  })
 
   var Obj = exports.Obj = function(proto, name) {
     if (!this.props) this.props = Object.create(null);
diff --git a/test/condense-utils.js b/test/condense-utils.js
new file mode 100644
index 00000000..833ed5e4
--- /dev/null
+++ b/test/condense-utils.js
@@ -0,0 +1,59 @@
+var util = require("./util");
+var tern = require("../lib/tern"), condense = require("../lib/condense");
+var fs = require("fs"), path = require("path");
+
+var condenseDir = "test/condense";
+exports.condenseConf = {
+  projectDir: path.resolve(__dirname, ".."),
+  resolve: function(pth) { return path.resolve(this.projectDir, pth); },
+  jsonFile: function(name) { return this.resolve(condenseDir + "/" + name.replace(/\.js$/, ".json")) }
+}
+
+exports.runTest = function(conf,options) {
+  var server = new tern.Server({
+    defs: [util.ecma5, util.browser],
+    plugins: options.plugins,
+    projectDir: conf.resolve(condenseDir),
+    getFile: function(name) {
+      return fs.readFileSync(path.resolve(condenseDir, name), "utf8");
+    }
+  });
+  options.load.forEach(function(file) {
+    server.addFile(file);
+  });
+  server.flush(function() {
+    var origins = options.include || options.load;
+    var condensed = condense.condense(origins, null, {sortOutput: true});
+    var out = JSON.stringify(condensed, null, 2);
+    var expect = fs.readFileSync(conf.jsonFile(origins[0]), "utf8").trim();
+    if (out != expect)
+      return util.failure("condense/" + origins[0] + ": Mismatch in condense output.\nGot " +
+                          out + "\nExpected " + expect);
+
+    // Test loading the condensed defs.
+    var server2 = new tern.Server({
+      defs: [util.ecma5, util.browser, condensed],
+      plugins: options.plugins
+    });
+    server2.flush(function() {
+      var condensed = condense.condense(origins, null, {sortOutput: true});
+      var out = JSON.stringify(condensed, null, 2);
+      if (out != expect)
+        util.failure("condense/" + origins[0] + ": Mismatch in condense output after loading defs. Got " +
+                     out + "\nExpected " + expect);
+    });
+  });
+}
+
+function jsFile(f) {
+  return f + ".js";
+}
+exports.testConf = function(condenseConf,filter,options) {
+  if (typeof options == "string") options = {load: [options]};
+  options.load = options.load.map(jsFile);
+  if (options.include) options.include = options.include.map(jsFile);
+  if (filter && options.load[0].indexOf(filter) == -1) return;
+  util.addTest();
+  util.addFile();
+  exports.runTest(condenseConf,options);
+}
\ No newline at end of file
diff --git a/test/condense.js b/test/condense.js
index bcd8a007..c93b8290 100644
--- a/test/condense.js
+++ b/test/condense.js
@@ -1,61 +1,9 @@
-var util = require("./util");
-var tern = require("../lib/tern"), condense = require("../lib/condense");
-var fs = require("fs"), path = require("path");
 require("../plugin/angular");
 require("../plugin/node");
-
-var condenseDir = "test/condense";
-function jsonFile(name) { return util.resolve(condenseDir + "/" + name.replace(/\.js$/, ".json")); }
-
-function runTest(options) {
-  var server = new tern.Server({
-    defs: [util.ecma5, util.browser],
-    plugins: options.plugins,
-    projectDir: util.resolve(condenseDir),
-    getFile: function(name) {
-      return fs.readFileSync(path.resolve(condenseDir, name), "utf8");
-    }
-  });
-  options.load.forEach(function(file) {
-    server.addFile(file);
-  });
-  server.flush(function() {
-    var origins = options.include || options.load;
-    var condensed = condense.condense(origins, null, {sortOutput: true});
-    var out = JSON.stringify(condensed, null, 2);
-    var expect = fs.readFileSync(jsonFile(origins[0]), "utf8").trim();
-    if (out != expect)
-      return util.failure("condense/" + origins[0] + ": Mismatch in condense output. Got " +
-                          out + "\nExpected " + expect);
-
-    // Test loading the condensed defs.
-    var server2 = new tern.Server({
-      defs: [util.ecma5, util.browser, condensed],
-      plugins: options.plugins
-    });
-    server2.flush(function() {
-      var condensed = condense.condense(origins, null, {sortOutput: true});
-      var out = JSON.stringify(condensed, null, 2);
-      if (out != expect)
-        util.failure("condense/" + origins[0] + ": Mismatch in condense output after loading defs. Got " +
-                     out + "\nExpected " + expect);
-    });
-  });
-}
+var condenseUtils = require("./condense-utils");
 
 exports.runTests = function(filter) {
-  function jsFile(f) {
-    return f + ".js";
-  }
-  function test(options) {
-    if (typeof options == "string") options = {load: [options]};
-    options.load = options.load.map(jsFile);
-    if (options.include) options.include = options.include.map(jsFile);
-    if (filter && options.load[0].indexOf(filter) == -1) return;
-    util.addTest();
-    util.addFile();
-    runTest(options);
-  }
+  function test(options) { condenseUtils.testConf(condenseUtils.condenseConf, filter, options) };
 
   test("basic");
   test("fn");
@@ -86,4 +34,4 @@ exports.runTests = function(filter) {
   test({load: ["requirejs_const", "requirejs_dep"], include: ["requirejs_dep", "requirejs_const"], plugins: {requirejs: true}});
 
   test("recursive");
-};
+}
diff --git a/test/def-parser.js b/test/def-parser.js
new file mode 100644
index 00000000..9463dedc
--- /dev/null
+++ b/test/def-parser.js
@@ -0,0 +1,30 @@
+var util = require("./util");
+
+var infer = require("../lib/infer");
+var def = require("../lib/def").init({}, infer);
+
+exports.runTests = function(filter) {
+  var cx = new infer.Context([],null);
+  infer.withContext(cx, function() {
+    cx.protos.Object = new infer.Obj(null, "Object.prototype");
+    cx.topScope = new infer.Scope();
+    cx.topScope.name = "<top>";
+    cx.protos.Array = new infer.Obj(true, "Array.prototype");
+    cx.protos.Function = new infer.Obj(true, "Function.prototype");
+    cx.protos.RegExp = new infer.Obj(true, "RegExp.prototype");
+    cx.protos.String = new infer.Obj(true, "String.prototype");
+    cx.protos.Number = new infer.Obj(true, "Number.prototype");
+    cx.protos.Boolean = new infer.Obj(true, "Boolean.prototype");
+    cx.str = new infer.Prim(cx.protos.String, "string");
+    cx.bool = new infer.Prim(cx.protos.Boolean, "bool");
+    cx.num = new infer.Prim(cx.protos.Number, "number");
+    cx.curOrigin = null;
+
+    var typeString = "(number|string)";
+    var unionType = new def.TypeParser(typeString, "", null, true).parseType("??", true);
+    util.addTest();
+    util.addFile();
+    if (unionType.toString() !== "(number|string)") util.failure("parsing " + typeString + " failed, got: " + unionType.toString());
+  });
+
+}
\ No newline at end of file