Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/smoke/src/common.dart

+// Copyright (c) 2014, 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.
+
+/// Some common utilities used by other libraries in this package.
+library smoke.src.common;
+
+import 'package:smoke/smoke.dart' as smoke show isSubclassOf;
+
+/// Returns [input] adjusted to be within [min] and [max] length. Truncating it
+/// if it's longer, or padding it with nulls if it's shorter. The returned list
+/// is a new copy if any modification is needed, otherwise [input] is returned.
+List adjustList(List input, int min, int max) {
+  if (input.length < min) {
+    return new List(min)..setRange(0, input.length, input);
+  }
+
+  if (input.length > max) {
+    return new List(max)..setRange(0, max, input);
+  }
+  return input;
+}
+
+/// Returns whether [metadata] contains any annotation that is either equal to
+/// an annotation in [queryAnnotations] or whose type is listed in
+/// [queryAnnotations].
+bool matchesAnnotation(Iterable metadata, Iterable queryAnnotations) {
+  for (var meta in metadata) {
+    for (var queryMeta in queryAnnotations) {
+      if (meta == queryMeta) return true;
+      if (queryMeta is Type &&
+          smoke.isSubclassOf(meta.runtimeType, queryMeta)) return true;
+    }
+  }
+  return false;
+}
+
+/// Number of arguments supported by [minArgs] and [maxArgs].
+const SUPPORTED_ARGS = 3;
+
+typedef _Func0();
+typedef _Func1(a);
+typedef _Func2(a, b);
+typedef _Func3(a, b, c);
+
+/// Returns the minimum number of arguments that [f] takes as input, in other
+/// words, the total number of required arguments of [f]. If [f] expects more
+/// than [SUPPORTED_ARGS], this function returns `SUPPORTED_ARGS + 1`.
+/// 
+/// For instance, the current implementation only supports calculating the
+/// number of arguments between `0` and `3`. If the function takes `4` or more,
+/// this function automatically returns `4`.
+int minArgs(Function f) {
+  if (f is _Func0) return 0;
+  if (f is _Func1) return 1;
+  if (f is _Func2) return 2;
+  if (f is _Func3) return 3;
+  return SUPPORTED_ARGS + 1;
+}
+
+/// Returns the maximum number of arguments that [f] takes as input, which is
+/// the total number of required and optional arguments of [f]. If
+/// [f] may take more than [SUPPORTED_ARGS] required arguments, this function
+/// returns `-1`. However, if it takes less required arguments, but more than
+/// [SUPPORTED_ARGS] arguments including optional arguments, the result will be
+/// [SUPPORTED_ARGS].
+///
+/// For instance, the current implementation only supports calculating the
+/// number of arguments between `0` and `3`.  If the function takes `4`
+/// mandatory arguments, this function returns `-1`, but if the funtion takes
+/// `2` mandatory arguments and 10 optional arguments, this function returns
+/// `3`.
+int maxArgs(Function f) {
+  if (f is _Func3) return 3;
+  if (f is _Func2) return 2;
+  if (f is _Func1) return 1;
+  if (f is _Func0) return 0;
+  return -1;
+}
+
+/// Shallow comparison of two lists.
+bool compareLists(List a, List b, {bool unordered: false}) {
+  if (a == null && b != null) return false;
+  if (a != null && b == null) return false;
+  if (a.length != b.length) return false;
+  if (unordered) {
+    var countMap = {};
+    for (var x in b) {
+      var count = countMap[x];
+      if (count == null) count = 0;
+      countMap[x] = count + 1;
+    }
+    for (var x in a) {
+      var count = countMap[x];
+      if (count == null) return false;
+      if (count == 1) {
+        countMap.remove(x);
+      } else {
+        countMap[x] = count - 1;
+      }
+    }
+    return countMap.isEmpty;
+  } else {
+    for (int i = 0; i < a.length; i++) {
+      if (a[i] != b[i]) return false;
+    }
+  }
+  return true;
+}
+
+/// Shallow comparison of two maps.
+bool compareMaps(Map a, Map b) {
+  if (a == null && b != null) return false;
+  if (a != null && b == null) return false;
+  if (a.length != b.length) return false;
+  for (var k in a.keys) {
+    if (!b.containsKey(k) || a[k] != b[k]) return false;
+  }
+  return true;
+}