Add simple binary that prints the inferred type information of a single function

bin/show_inferred_types.dart

Index: bin/show_inferred_types.dart
diff --git a/bin/show_inferred_types.dart b/bin/show_inferred_types.dart
new file mode 100644
index 0000000000000000000000000000000000000000..f8d509adea3116bafb7bc198189cb6423eee496c
--- /dev/null
+++ b/bin/show_inferred_types.dart
@@ -0,0 +1,58 @@
+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// Simple script that shows the inferred types of a function.
+library compiler.tool.show_inferred_types;
+
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:dart2js_info/info.dart';
+import 'package:dart2js_info/src/util.dart';
+
+main(args) {
+  if (args.length < 2) {
+    var scriptName = Platform.script.pathSegments.last;
+    print('usage: dart $scriptName <info.json> <function-name-regex> [-l]');
+    print('  -l: print the long qualified name for a function.');
+    exit(1);
+  }
+
+  var showLongName = args.length > 2 && args[2] == '-l';
+
+  var json = JSON.decode(new File(args[0]).readAsStringSync());
+  var info = new AllInfoJsonCodec().decode(json);
+  var nameRegExp = new RegExp(args[1]);
+  matches(e) => nameRegExp.hasMatch(longName(e));
+
+  bool noResults = true;
+  void showMethods() {
+    var sources = info.functions.where(matches).toList();
+    if (sources.isEmpty) return;
+    noResults = false;
+    for (var s in sources) {
+      var params = s.parameters.map((p) => '${p.name}: ${p.type}').join(', ');
+      var name = showLongName ? longName(s) : s.name;
+      print('$name($params): ${s.returnType}');
+    }
+  }
+
+  void showFields() {
+    var sources = info.fields.where(matches).toList();
+    if (sources.isEmpty) return;
+    noResults = false;
+    for (var s in sources) {
+      var name = showLongName ? longName(s) : s.name;
+      print('$name: ${s.inferredType}');
+    }
+  }
+
+  showMethods();
+  showFields();
+  if (noResults) {
+    print('error: no function or field that matches ${args[1]} was found.');
+    exit(1);
+  }
+}
+