xo-expression2 xo-reader2 DSequenceExpr, DSequenceSsm [WIP]

include/xo/reader2/DDefineSsm.hpp

@@ -169,21 +169,6 @@ namespace xo {
             void on_parsed_typedescr(TypeDescr td,
                                      ParserStateMachine * p_psm);
 
-#ifdef OBSOLETE
-            /** update state for this ssm to consume param (name,value)
-             *  emitted by nested @p_psm
-             **/
-            void on_parsed_formal(const DUniqueString * param_name,
-                                  TypeDescr param_type,
-                                  ParserStateMachine * p_psm);
-
-            /** consume formal params @p arglist from completed nested ssm,
-             *  with overall parser state in @p p_psm.
-             **/
-            void on_parsed_formal_arglist(DArray * arglist,
-                                          ParserStateMachine * p_psm);
-#endif
-
             /** update state for this syntax after parsing an expression @p expr,
              *  overall parser state in @p p_psm
              **/

include/xo/reader2/DSequenceSsm.hpp

@@ -0,0 +1,57 @@
+/** @file DSequenceSsm.hpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#pragma once
+
+#include "DSyntaxStateMachine.hpp"
+//#include "exprstate.hpp"
+
+namespace xo {
+    namespace scm { class Sequence; }
+    namespace scm { class Lambda; }
+
+    namespace scm {
+        class DSequenceSsm : public DSyntaxStateMachine<DSequenceSsm> {
+        public:
+            using Sequence = xo::scm::Sequence;
+            using Lambda = xo::scm::Lambda;
+
+        public:
+            const char * ssm_classname() const noexcept { return "DSequenceSsm"; }
+
+#ifdef NOT_YET
+            /** start parsing a sequence-expr.
+             *  input begins with first expression in the sequence.
+             **/
+            static void start(parserstatemachine * p_psm);
+
+            /** named ctor idiom **/
+            static std::unique_ptr<sequence_xs> make();
+
+            virtual void on_expr(bp<Expression> expr,
+                                 parserstatemachine * p_psm) override;
+            virtual void on_expr_with_semicolon(bp<Expression> expr,
+                                                parserstatemachine * p_psm) override;
+
+            virtual void on_rightbrace_token(const token_type & tk,
+                                             parserstatemachine * p_psm) override;
+
+            virtual void print(std::ostream & os) const override;
+            virtual bool pretty_print(const xo::print::ppindentinfo & ppii) const override;
+#endif
+
+        private:
+            DSequenceSsm();
+
+        private:
+            /** will build SequenceExpr from in-order contents of this array **/
+            DArray * expr_v_;
+            //std::vector<rp<Expression>> expr_v_;
+        };
+    } /*namespace scm*/
+} /*namespace xo*/
+
+
+/* end DSequenceSsm.hpp */