xo-reader: doc: ++ comments

include/xo/reader/parserstatemachine.hpp

@@ -50,6 +50,9 @@ namespace xo {
             exprstatestack * p_stack_;
             /** stack of environment frames, one for each enclosing lambda **/
             envframestack * p_env_stack_;
+            /** if non-null,  store next non-nested complete expressions in
+             *  *p_emit_expr
+             **/
             rp<Expression> * p_emit_expr_;
         };
     } /*namespace scm*/

include/xo/reader/progress_xs.hpp

@@ -11,7 +11,11 @@
 
 namespace xo {
     namespace scm {
-        /* represent an infix operator */
+        /** represent an infix operator.
+         *
+         *  See @ref progress_xs::assemble_expr() for translation
+         *  to Expression
+         **/
         enum class optype {
             invalid = -1,
 
@@ -26,6 +30,9 @@ namespace xo {
         extern const char *
         optype_descr(optype x);
 
+        /** report operator precedence.
+         *  lowest operator precedence is 1
+         **/
         extern int
         precedence(optype x);
 

src/reader/expect_expr_xs.cpp

@@ -92,8 +92,6 @@ namespace xo {
             constexpr bool c_debug_flag = true;
             scope log(XO_DEBUG(c_debug_flag));
 
-            //constexpr const char * self_name = "exprstate::on_leftparen";
-
             /* push lparen_0 to remember to look for subsequent rightparen. */
             sequence_xs::start(p_psm);
         }