xo-expression/xo-reader: refactor Environment -> SymbolTable

xo-expression/src/expression/GlobalSymtab.cpp

@@ -0,0 +1,61 @@
+/* file GlobalEnv.cpp
+ *
+ * author: Roland Conybeare, Jul 2025
+ */
+
+#include "xo/indentlog/print/ppdetail_atomic.hpp"
+#include "GlobalSymtab.hpp"
+#include "Expression.hpp"
+
+namespace xo {
+    namespace scm {
+        GlobalSymtab::GlobalSymtab() = default;
+
+        bp<Expression>
+        GlobalSymtab::require_global(const std::string & vname,
+                                  bp<Expression> expr)
+        {
+            this->global_map_[vname] = expr.get();
+
+            return expr;
+        } /*require_global*/
+
+        void
+        GlobalSymtab::upsert_local(bp<Variable> target) {
+            // in practice: paraphrase of .require_global()
+
+            this->global_map_[target->name()] = target.promote();
+        }
+
+        void
+        GlobalSymtab::print(std::ostream & os) const {
+            os << "<GlobalEnv"
+               << xtag("size", global_map_.size())
+               << ">";
+        }
+
+        std::uint32_t
+        GlobalSymtab::pretty_print(const xo::print::ppindentinfo & ppii) const
+        {
+            using xo::print::ppstate;
+
+            ppstate * pps = ppii.pps();
+
+            if (ppii.upto()) {
+                if (!pps->print_upto("<GlobalEnv"))
+                    return false;
+                if (!pps->print_upto_tag("size", global_map_.size()))
+                    return false;
+                pps->write(">");
+
+                return true;
+            } else {
+                pps->write("<GlobalEnv");
+                pps->newline_pretty_tag(ppii.ci1(), "size", global_map_.size());
+                pps->write(">");
+
+                return false;
+            }
+        }
+    } /*namespace scm*/
+} /*namespace xo*/