1 files changed, 48 insertions, 0 deletions
diff --git a/node_modules/postcss-zindex/lib/layerCache.js b/node_modules/postcss-zindex/lib/layerCache.js
new file mode 100644
index 00000000..b6433c60
--- /dev/null
+++ b/node_modules/postcss-zindex/lib/layerCache.js
@@ -0,0 +1,48 @@
+'use strict';
+
+var has = require('has');
+var uniq = require('uniqs');
+
+function LayerCache (opts) {
+    if (!(this instanceof LayerCache)) {
+        return new LayerCache(opts);
+    }
+    this._values = [];
+    this._startIndex = opts.startIndex || 1;
+}
+
+function ascending (a, b) {
+    return a - b;
+}
+
+function reduceValues (list, value, index) {
+    list[value] = index + this._startIndex;
+    return list;
+}
+
+LayerCache.prototype._findValue = function (value) {
+    if (has(this._values, value)) {
+        return this._values[value];
+    }
+    return false;
+};
+
+LayerCache.prototype.optimizeValues = function () {
+    this._values = uniq(this._values).sort(ascending).reduce(reduceValues.bind(this), {});
+};
+
+LayerCache.prototype.addValue = function (value) {
+    var parsedValue = parseInt(value, 10);
+    // pass only valid values
+    if (!parsedValue || parsedValue < 0) {
+        return;
+    }
+    this._values.push(parsedValue);
+};
+
+LayerCache.prototype.getValue = function (value) {
+    var parsedValue = parseInt(value, 10);
+    return this._findValue(parsedValue) || value;
+};
+
+module.exports = LayerCache;