1 files changed, 81 insertions, 0 deletions
diff --git a/src/queue.js b/src/queue.js
new file mode 100644
index 0000000..abcfb84
--- /dev/null
+++ b/src/queue.js
@@ -0,0 +1,81 @@
+SVG.Queue = SVG.invent({
+  create: function () {
+    this._first = null
+    this._last = null
+    this.length = 0
+    this.id = 0
+  },
+
+  extend: {
+    push: function (value) {
+
+      // An item stores an id and the provided value
+      var item = { id: this.id++, value: value }
+
+      // Deal with the queue being empty or populated
+      if (this._last) {
+        this._last = this._last.next = item
+      } else {
+        this._last = this._first = item
+      }
+
+      this.length++
+    },
+
+    shift: function () {
+      if (this.length == 0) {
+        return
+      }
+
+      var remove = this._first
+      this._first = remove.next
+      this._last = --this.length ? this._last : null
+      return remove.value
+    },
+
+    // Shows us the first item in the list
+    first: function () {
+      return this._first && this._first.value
+    },
+
+    // Shows us the last item in the list
+    last: function () {
+      return this._last && this._last.value
+    },
+
+    // Removes the first item from the front where matcher returns true
+    remove: function (matcher) {
+      // Find the first match
+      var previous = null
+      var current = this._first
+      while (current) {
+
+        // If we have a match, we are done
+        if (matcher(current)) break
+
+        // Otherwise, advance both of the pointers
+        previous = current
+        current = current.next
+      }
+
+      // If we got the first item, adjust the first pointer
+      if (current && current === this._first)
+        this._first = this._first.next
+
+      // If we got the last item, adjust the last pointer
+      if (current && current === this._last)
+        this._last = previous
+
+      // If we got an item, fix the list and return the item
+      if (current) {
+        --this.length
+
+        if (previous) {
+          previous.next = current.next
+        }
+
+        return current.item
+      }
+    }
+  }
+})