aboutsummaryrefslogtreecommitdiff
path: root/node_modules/fbjs/lib/minBy.js.flow
diff options
context:
space:
mode:
Diffstat (limited to 'node_modules/fbjs/lib/minBy.js.flow')
-rw-r--r--node_modules/fbjs/lib/minBy.js.flow37
1 files changed, 37 insertions, 0 deletions
diff --git a/node_modules/fbjs/lib/minBy.js.flow b/node_modules/fbjs/lib/minBy.js.flow
new file mode 100644
index 000000000..a76aec4fa
--- /dev/null
+++ b/node_modules/fbjs/lib/minBy.js.flow
@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule minBy
+ * @flow
+ */
+
+var compareNumber = (a, b) => a - b;
+
+/**
+ * Returns the minimum element as measured by a scoring function f. Returns the
+ * first such element if there are ties.
+ */
+function minBy<A, B>(as: Iterable<A>, f: (a: A) => B, compare?: ?(u: B, v: B) => number): ?A {
+ compare = compare || (compareNumber: any);
+
+ var minA = undefined;
+ var minB = undefined;
+ var seenFirst = false;
+ for (var a of as) {
+ var b = f(a);
+ if (!seenFirst || compare(b, (minB: any)) < 0) {
+ minA = a;
+ minB = b;
+ seenFirst = true;
+ }
+ }
+
+ return minA;
+}
+
+module.exports = minBy; \ No newline at end of file