first commit

1 files changed, 42 insertions, 0 deletions

diff --git a/src/Sequence.php b/src/Sequence.php
new file mode 100644
index 0000000..d799e29
--- /dev/null
+++ b/src/Sequence.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Zhineng\Snowflake;
+
+final class Sequence extends Field
+{
+    use Makable;
+
+    /**
+     * The current value.
+     */
+    private int $value = 0;
+
+    public function value(): int
+    {
+        return $this->next();
+    }
+
+    public function next(): int
+    {
+        $current = $this->value++;
+
+        if ($current > $this->maxValue()) {
+            throw new \OverflowException(sprintf(
+                'Sequence "%s" exceeded its maximum value of %d.',
+                $this->name,
+                $this->maxValue()
+            ));
+        }
+
+        return $current;
+    }
+
+    public function reset(): self
+    {
+        $this->value = 0;
+
+        return $this;
+    }
+}