xo-interpreter2 stack: wrap TokenizerError as DRuntimeError

Also fix _read_eval_print() to report them!

src/tokenizer2/CMakeLists.txt

@@ -11,6 +11,7 @@ set(SELF_SRCS
 
 xo_add_shared_library4(${SELF_LIB} ${PROJECT_NAME}Targets ${PROJECT_VERSION} 1 ${SELF_SRCS})
 # deps must coordinate with xo-tokenizer/cmake/xo_tokenizer2Config.cmake.in
+xo_dependency(${SELF_LIB} xo_stringtable2)
 xo_dependency(${SELF_LIB} xo_arena)
 xo_dependency(${SELF_LIB} indentlog)
 

src/tokenizer2/TokenizerError.cpp

@@ -54,6 +54,20 @@ namespace xo {
             }
         }
 
+        DString *
+        TokenizerError::report_to_string(obj<AAllocator> dest_mm) const
+        {
+            // FIXME:
+            // using heap here for scratch space.
+            // Would prefer to checkpoint + realloc.
+
+            std::stringstream ss;
+
+            this->report(ss);
+
+            return DString::from_str(dest_mm, ss.str());
+        }
+
     } /*namespace scm*/
 } /*namespace xo*/