Add 'xo-reader/' from commit 'c46c0f1cc4'

git-subtree-dir: xo-reader
git-subtree-mainline: dacdeb2cd7
git-subtree-split: c46c0f1cc4

xo-reader/include/xo/reader/lambda_xs.hpp

@@ -0,0 +1,84 @@
+/** @file lambda_xs.hpp
+ *
+ *  Author: Roland Conybeare
+ **/
+
+#pragma once
+
+#include "exprstate.hpp"
+//#include <cstdint>
+
+namespace xo {
+    namespace scm {
+        /**
+         *   lambda ( name(1) : type(1), ..., ) body-expr ;
+         *  ^      ^                           ^         ^
+         *  |      |                           |         |
+         *  lm_0   lm_1                        lm_2      lm_3
+         *
+         *  lm_0 --on_lambda_token()--> lm_1
+         *  lm_1 --on_formal_arglist()--> lm_2
+         *  lm_2 --on_expr()--> lm_3
+         *  lm_3 --on_semicolon_token()--> (done)
+         **/
+        enum class lambdastatetype {
+            invalid = -1,
+
+            lm_0,
+            lm_1,
+            lm_2,
+            lm_3,
+
+            n_lambdastatetype
+        };
+
+        extern const char *
+        lambdastatetype_descr(lambdastatetype x);
+
+        inline std::ostream &
+        operator<< (std::ostream & os, lambdastatetype x) {
+            os << lambdastatetype_descr(x);
+            return os;
+        }
+
+        /** @class lambda_xs
+         *  @brief parsing state-machine for a lambda-expression
+         *
+         **/
+        class lambda_xs : public exprstate {
+        public:
+            lambda_xs();
+
+            static void start(parserstatemachine * p_psm);
+
+            virtual void on_lambda_token(const token_type & tk,
+                                         parserstatemachine * p_psm) override;
+            virtual void on_formal_arglist(const std::vector<rp<Variable>> & argl,
+                                           parserstatemachine * p_psm) override;
+            virtual void on_expr(ref::brw<Expression> expr,
+                                 parserstatemachine * p_psm) override;
+            virtual void on_expr_with_semicolon(ref::brw<Expression> expr,
+                                                parserstatemachine * p_psm) override;
+            virtual void on_semicolon_token(const token_type & tk,
+                                            parserstatemachine * p_psm) override;
+
+            virtual void print(std::ostream & os) const override;
+
+        private:
+            static std::unique_ptr<lambda_xs> make();
+
+        private:
+            /** parsing state-machine state **/
+            lambdastatetype lmxs_type_ = lambdastatetype::lm_0;
+
+            /** formal parameter list **/
+            std::vector<rp<Variable>> argl_;
+
+            /** body expression **/
+            rp<Expression> body_;
+        };
+    } /*namespace scm*/
+} /*namespace xo*/
+
+
+/** end lambda_xs.hpp **/