1 files changed, 27 insertions, 0 deletions
diff --git a/lib/exTpl/Expression.php b/lib/exTpl/Expression.php
new file mode 100644
index 0000000..15a485d
--- /dev/null
+++ b/lib/exTpl/Expression.php
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+<?php
+/*
+ * Expression.php - template parser expression interface and classes
+ *
+ * Copyright (c) 2013  Elmar Ludwig
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+namespace exTpl;
+
+/**
+ * Basic interface for expressions in the template parse tree. The
+ * only required method is "value" to get the expression's value.
+ */
+interface Expression
+{
+    /**
+     * Returns the value of this expression.
+     *
+     * @param Context $context  symbol table
+     */
+    public function value(Context $context): mixed;
+}