xo-expression: initial commit (constant + primitive)

include/xo/expression/Apply.hpp

@@ -0,0 +1,32 @@
+/** @file Apply.hpp
+ *
+ *  Author: Roland Conybeare
+ **/
+
+#pragma once
+
+#include "Expression.hpp"
+
+//#include <cstdint>
+
+namespace xo {
+    namespace ast {
+        /** @class Apply
+         *  @brief syntax for a function call.
+         *
+         *  In general we don't know function to be invoked
+         *  until runtime,  depending on the nature of Expression.
+         *
+         *  For first cut,  we'll just handle the case of a Constant
+         *  that refers to a known function
+         **/
+        class Apply : public Expression {
+            ref::rp<Expression> fn_;
+            std::vector<ref::rp<Expression>> args_;
+        };
+    } /*namespace ast*/
+
+} /*namespace xo*/
+
+
+/** end Apply.hpp **/