xo-reader: wip: + envframe, envframestack [not used]

include/xo/reader/envframe.hpp

@@ -0,0 +1,48 @@
+/* file envframe.hpp
+ *
+ * author: Roland Conybeare, Aug 2024
+ */
+
+#pragma once
+
+#include "xo/expression/Variable.hpp"
+#include <vector>
+
+namespace xo {
+    namespace scm {
+        /** @class envframe
+         *  @brief names/types of formal paremeters introduced by a function
+         *
+         *
+         **/
+        class envframe {
+        public:
+            using Variable = xo::ast::Variable;
+
+        public:
+            envframe() = default;
+            envframe(const std::vector<rp<Variable>> & argl) : argl_(argl) {}
+
+            const std::vector<rp<Variable>> & argl() const { return argl_; }
+
+            /** lookup variable by name.  If found, return it.
+             *  Otherwise return nullptr
+             **/
+            rp<Variable> lookup(const std::string & name) const;
+
+            void print (std::ostream & os) const;
+
+        private:
+            std::vector<rp<Variable>> argl_;
+        };
+
+        inline std::ostream &
+        operator<< (std::ostream & os, const envframe & x) {
+            x.print(os);
+            return os;
+        }
+    } /*namespace scm*/
+} /*namespace xo*/
+
+
+/* end envframe.hpp */

include/xo/reader/envframestack.hpp

@@ -0,0 +1,66 @@
+/* file envframestack.hpp
+ *
+ * author: Roland Conybeare, Aug 2024
+ */
+
+#pragma once
+
+#include "envframe.hpp"
+
+namespace xo {
+    namespace scm {
+        /** @class envframestack
+         *  @brief A stack of envframe objects
+         **/
+        class envframestack {
+        public:
+            envframestack() {}
+
+            bool empty() const { return stack_.empty(); }
+            std::size_t size() const { return stack_.size(); }
+
+            envframe & top_envframe();
+            void push_envframe(envframe x);
+            void pop_envframe();
+
+            /** relative to top-of-stack.
+             *  0 -> top (last in),  z-1 -> bottom (first in)
+             **/
+            envframe & operator[](std::size_t i) {
+                std::size_t z = stack_.size();
+
+                assert(i < z);
+
+                return stack_[z - i - 1];
+            }
+
+            const envframe & operator[](std::size_t i) const {
+                std::size_t z = stack_.size();
+
+                assert(i < z);
+
+                return stack_[z - i - 1];
+            }
+
+            void print (std::ostream & os) const;
+
+        private:
+            std::vector<envframe> stack_;
+        };
+
+        inline std::ostream &
+        operator<< (std::ostream & os, const envframestack & x) {
+            x.print(os);
+            return os;
+        }
+
+        inline std::ostream &
+        operator<< (std::ostream & os, const envframestack * x) {
+            x->print(os);
+            return os;
+        }
+    } /*namespace scm*/
+} /*namespace xo*/
+
+
+/* end envframestack.hpp */

src/reader/CMakeLists.txt

@@ -13,11 +13,12 @@ set(SELF_SRCS
     exprseq_xs.cpp
     expect_expr_xs.cpp
     expect_symbol_xs.cpp
-
     expect_formal_xs.cpp
     expect_formal_arglist_xs.cpp
     expect_type_xs.cpp
-    lambda_xs.cpp)
+    lambda_xs.cpp
+    envframestack.cpp
+    envframe.cpp)
 
 xo_add_shared_library4(${SELF_LIB} ${PROJECT_NAME}Targets ${PROJECT_VERSION} 1 ${SELF_SRCS})
 xo_dependency(${SELF_LIB} xo_expression)

src/reader/envframe.cpp

@@ -0,0 +1,34 @@
+/* file envframe.cpp
+ *
+ * author: Roland Conybeare
+ */
+
+#include "envframe.hpp"
+#include "xo/indentlog/print/vector.hpp"
+
+namespace xo {
+    using xo::ast::Variable;
+
+    namespace scm {
+        rp<Variable>
+        envframe::lookup(const std::string & x) const {
+            for (const auto & var : argl_) {
+                if (x == var->name())
+                    return var;
+            }
+
+            return nullptr;
+        }
+
+        void
+        envframe::print(std::ostream & os) const {
+            os << "<envframe"
+               << xtag("argl", argl_)
+               << ">";
+        }
+
+    } /*namespace scm */
+} /*namespace xo*/
+
+
+/* end envframe.cpp */

src/reader/envframestack.cpp

@@ -0,0 +1,70 @@
+/* file envframestack.cpp
+ *
+ * author: Roland Conybeare
+ */
+
+#include "envframestack.hpp"
+
+namespace xo {
+    namespace scm {
+        envframe &
+        envframestack::top_envframe() {
+            std::size_t z = stack_.size();
+
+            if (z == 0) {
+                throw std::runtime_error
+                    ("parser::top_exprstate: unexpected empty stack");
+            }
+
+            return stack_[z-1];
+        }
+
+        void
+        envframestack::push_envframe(envframe frame) {
+            constexpr bool c_debug_flag = true;
+            scope log(XO_DEBUG(c_debug_flag),
+                      xtag("frame", frame));
+
+            std::size_t z = stack_.size();
+
+            stack_.resize(z+1);
+
+            stack_[z] = std::move(frame);
+        }
+
+        void
+        envframestack::pop_envframe() {
+            constexpr bool c_debug_flag = true;
+            scope log(XO_DEBUG(c_debug_flag));
+
+            std::size_t z = stack_.size();
+
+            if (z > 0) {
+                //std::unique_ptr<exprstate> top = std::move(stack_[z-1]);
+
+                stack_.resize(z-1);
+
+                //return top;
+            } else {
+                //return nullptr;
+            }
+        }
+
+        void
+        envframestack::print(std::ostream & os) const {
+            os << "<envframestack"
+               << xtag("size", stack_.size())
+               << std::endl;
+
+            for (std::size_t i = 0, z = stack_.size(); i < z; ++i) {
+                os << "  [" << z-i-1 << "] "
+                   << stack_[i]
+                   << std::endl;
+            }
+
+            os << ">" << std::endl;
+        }
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end envframestack.cpp */