1 files changed, 57 insertions, 0 deletions
diff --git a/lib/querypath/src/QueryPath/CSS/InputStream.php b/lib/querypath/src/QueryPath/CSS/InputStream.php
new file mode 100644
index 0000000..2967845
--- /dev/null
+++ b/lib/querypath/src/QueryPath/CSS/InputStream.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * @file
+ *
+ * The CSS Input Stream abstraction.
+ */
+
+namespace QueryPath\CSS;
+
+/**
+ * Simple wrapper to turn a string into an input stream.
+ * This provides a standard interface on top of an array of
+ * characters.
+ */
+class InputStream {
+  protected $stream = NULL;
+  public $position = 0;
+  /**
+   * Build a new CSS input stream from a string.
+   *
+   * @param string
+   *  String to turn into an input stream.
+   */
+  function __construct($string) {
+    $this->stream = str_split($string);
+  }
+  /**
+   * Look ahead one character.
+   *
+   * @return char
+   *  Returns the next character, but does not remove it from
+   *  the stream.
+   */
+  function peek() {
+    return $this->stream[0];
+  }
+  /**
+   * Get the next unconsumed character in the stream.
+   * This will remove that character from the front of the
+   * stream and return it.
+   */
+  function consume() {
+    $ret = array_shift($this->stream);
+    if (!empty($ret)) {
+      $this->position++;
+    }
+    return $ret;
+  }
+  /**
+   * Check if the stream is empty.
+   * @return boolean
+   *   Returns TRUE when the stream is empty, FALSE otherwise.
+   */
+  function isEmpty() {
+    return count($this->stream) == 0;
+  }
+}