1 files changed, 33 insertions, 0 deletions
diff --git a/src/Search/CharSource.php b/src/Search/CharSource.php
new file mode 100644
index 0000000..165e538
--- /dev/null
+++ b/src/Search/CharSource.php
@@ -0,0 +1,33 @@
+<?php
+
+
+namespace Micropoly\Search;
+
+
+class CharSource
+{
+    private string $s;
+    private int $i = 0;
+    private int $len;
+
+    public function __construct(string $s)
+    {
+        $this->s = $s;
+        $this->len = mb_strlen($s);
+    }
+
+    public function getNext(): ?string
+    {
+        if ($this->i >= $this->len)
+            return null;
+
+        $c = mb_substr($this->s, $this->i, 1);
+        $this->i++;
+        return $c;
+    }
+
+    public function unget(): void
+    {
+        $this->i = max(0, $this->i - 1);
+    }
+}
+\ No newline at end of file