Initial commit

src/TokenList.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace NoccyLabs\PhpCalc;
+/**
+ * Helper class to iterate over a list of tokens
+ * 
+ * @license GPL V3 or later
+ * @copyright (c) 2022, NoccyLabs
+ */
+class TokenList
+{
+
+    private array $toks;
+
+    private int $ptr = 0;
+
+    public function __construct(array $toks)
+    {
+        $this->toks = $toks;
+    }
+
+    public function current(): ?string
+    {
+        return ($this->ptr >= count($this->toks) ? null : $this->toks[$this->ptr]);
+    }
+
+    public function read(): ?string
+    {
+        $v  = $this->current();
+        $this->next();
+        return $v;
+    }
+
+    public function next(): ?string
+    {
+        if ($this->ptr < count($this->toks)) {
+            $this->ptr++;
+            return ($this->ptr < count($this->toks) ? $this->toks[$this->ptr] : null);
+        }
+        return null;
+    }
+}