aboutsummaryrefslogtreecommitdiff
path: root/node_modules/array-uniq/index.js
diff options
context:
space:
mode:
Diffstat (limited to 'node_modules/array-uniq/index.js')
-rw-r--r--node_modules/array-uniq/index.js62
1 files changed, 62 insertions, 0 deletions
diff --git a/node_modules/array-uniq/index.js b/node_modules/array-uniq/index.js
new file mode 100644
index 0000000..edd09f8
--- /dev/null
+++ b/node_modules/array-uniq/index.js
@@ -0,0 +1,62 @@
+'use strict';
+
+// there's 3 implementations written in increasing order of efficiency
+
+// 1 - no Set type is defined
+function uniqNoSet(arr) {
+ var ret = [];
+
+ for (var i = 0; i < arr.length; i++) {
+ if (ret.indexOf(arr[i]) === -1) {
+ ret.push(arr[i]);
+ }
+ }
+
+ return ret;
+}
+
+// 2 - a simple Set type is defined
+function uniqSet(arr) {
+ var seen = new Set();
+ return arr.filter(function (el) {
+ if (!seen.has(el)) {
+ seen.add(el);
+ return true;
+ }
+
+ return false;
+ });
+}
+
+// 3 - a standard Set type is defined and it has a forEach method
+function uniqSetWithForEach(arr) {
+ var ret = [];
+
+ (new Set(arr)).forEach(function (el) {
+ ret.push(el);
+ });
+
+ return ret;
+}
+
+// V8 currently has a broken implementation
+// https://github.com/joyent/node/issues/8449
+function doesForEachActuallyWork() {
+ var ret = false;
+
+ (new Set([true])).forEach(function (el) {
+ ret = el;
+ });
+
+ return ret === true;
+}
+
+if ('Set' in global) {
+ if (typeof Set.prototype.forEach === 'function' && doesForEachActuallyWork()) {
+ module.exports = uniqSetWithForEach;
+ } else {
+ module.exports = uniqSet;
+ }
+} else {
+ module.exports = uniqNoSet;
+}