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

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

xo-reader/src/reader/parser.cpp

@@ -0,0 +1,81 @@
+/* file parser.cpp
+ *
+ * author: Roland Conybeare
+ */
+
+#include "parser.hpp"
+#include "parserstatemachine.hpp"
+#include "define_xs.hpp"
+#include "exprseq_xs.hpp"
+#include "xo/expression/DefineExpr.hpp"
+#include "xo/expression/Constant.hpp"
+#include "xo/expression/ConvertExpr.hpp"
+//#include <regex>
+#include <stdexcept>
+
+namespace xo {
+    using xo::ast::Expression;
+    //using xo::ast::DefineExpr;
+    //using xo::ast::ConvertExpr;
+    //using xo::ast::Constant;
+    //using xo::reflect::Reflect;
+    using xo::reflect::TypeDescr;
+
+    namespace scm {
+        // ----- parser -----
+
+        bool
+        parser::has_incomplete_expr() const {
+            return !xs_stack_.empty();
+        }
+
+        void
+        parser::begin_translation_unit() {
+            /* note: not using emit expr here */
+            parserstatemachine psm(&xs_stack_,
+                                   &env_stack_,
+                                   nullptr /*p_emit_expr*/);
+
+            exprseq_xs::start(&psm);
+        }
+
+        rp<Expression>
+        parser::include_token(const token_type & tk)
+        {
+            constexpr bool c_debug_flag = true;
+            scope log(XO_DEBUG(c_debug_flag), xtag("tk", tk));
+
+            if (xs_stack_.empty()) {
+                throw std::runtime_error(tostr("parser::include_token",
+                                                ": parser not expecting input"
+                                               "(call parser.begin_translation_unit()..?)",
+                                               xtag("token", tk)));
+            }
+
+            /* stack_ is non-empty */
+
+            rp<Expression> retval;
+
+            parserstatemachine psm(&xs_stack_, &env_stack_, &retval);
+
+            xs_stack_.top_exprstate().on_input(tk, &psm);
+
+            log && log(xtag("retval", retval));
+
+            return retval;
+        } /*include_token*/
+
+        void
+        parser::print(std::ostream & os) const {
+            os << "<parser"
+               << std::endl;
+
+            xs_stack_.print(os);
+
+            os << ">" << std::endl;
+        }
+    } /*namespace scm*/
+} /*namespace xo*/
+
+
+/* end parser.cpp */