ParameterHandler::parse_input_from_json(): mangle entries internally

Co-authored-by: Magdalena Schreter-Fleischhacker <schreter.magdalena@gmail.com>

doc/news/changes/incompatibilities/20240126SchreterMunch

@@ -0,0 +1,4 @@
+Changed:`ParameterHandler::parse_input_from_json()` reads now a json-file 
+without mangled parameter names.
+<br>
+(Magdalena Schreter, Peter Munch, 2024/01/26)

source/base/parameter_handler.cc

@@ -332,15 +332,15 @@ namespace
   }
 
   /**
-   * Demangle all parameters recursively and attach them to @p tree_out.
+   * Mangle or demangle all parameters recursively and attach them to @p tree_out.
    * @p is_parameter_or_alias_node indicates, whether a given node
    * @p tree_in is a parameter node or an alias node (as opposed to being
    * a subsection).
    */
   void
-  recursively_demangle(const boost::property_tree::ptree &tree_in,
-                       boost::property_tree::ptree       &tree_out,
-                       const bool is_parameter_or_alias_node = false)
+  recursively_mangle_or_demangle(const boost::property_tree::ptree &tree_in,
+                                 boost::property_tree::ptree       &tree_out,
+                                 const bool is_parameter_or_alias_node = false)
   {
     for (const auto &p : tree_in)
       {
@@ -355,10 +355,10 @@ namespace
             if (const auto val = p.second.get_value_optional<std::string>())
               temp.put_value<std::string>(*val);
 
-            recursively_demangle(p.second,
-                                 temp,
-                                 is_parameter_node(p.second) ||
-                                   is_alias_node(p.second));
+            recursively_mangle_or_demangle(p.second,
+                                           temp,
+                                           is_parameter_node(p.second) ||
+                                             is_alias_node(p.second));
             tree_out.put_child(demangle(p.first), temp);
           }
       }
@@ -808,9 +808,12 @@ ParameterHandler::parse_input_from_json(std::istream &in,
     }
 
   // The xml function is reused to read in the xml into the parameter file.
-  // This means that only mangled files can be read.
+  // This function can only read mangled files. Therefore, we create a mangeled
+  // tree first.
+  boost::property_tree::ptree node_tree_mangled;
+  recursively_mangle_or_demangle(node_tree, node_tree_mangled);
   read_xml_recursively(
-    node_tree, "", path_separator, patterns, skip_undefined, *this);
+    node_tree_mangled, "", path_separator, patterns, skip_undefined, *this);
 }
 
 
@@ -1343,7 +1346,8 @@ ParameterHandler::print_parameters(std::ostream     &out,
   if ((style & JSON) != 0)
     {
       boost::property_tree::ptree current_entries_damangled;
-      recursively_demangle(current_entries, current_entries_damangled);
+      recursively_mangle_or_demangle(current_entries,
+                                     current_entries_damangled);
       write_json(out, current_entries_damangled);
       return out;
     }

tests/parameter_handler/parameter_handler_read_json.cc → tests/parameter_handler/parameter_handler_read_json_01.cc

@@ -15,7 +15,7 @@
 
 
 
-// check ParameterHandler::parse_input_from_xml
+// check ParameterHandler::parse_input_from_json
 
 #include <deal.II/base/parameter_handler.h>
 
@@ -61,7 +61,7 @@ main()
   prm.leave_subsection();
 
   // read from json
-  std::ifstream in(SOURCE_DIR "/prm/parameter_handler_read_json.prm");
+  std::ifstream in(SOURCE_DIR "/prm/parameter_handler_read_json_01.json");
   prm.parse_input_from_json(in);
 
   Assert(int1 == 2, ExcNotImplemented());

tests/parameter_handler/parameter_handler_read_json_02.cc

@@ -43,7 +43,7 @@ main()
   prm.leave_subsection();
 
   // read from json
-  std::ifstream in(SOURCE_DIR "/prm/parameter_handler_read_json_02.prm");
+  std::ifstream in(SOURCE_DIR "/prm/parameter_handler_read_json_02.json");
   prm.parse_input_from_json(in, true);
 
   AssertDimension(int1, 1);

tests/parameter_handler/prm/parameter_handler_read_json.prm → tests/parameter_handler/prm/parameter_handler_read_json_01.json

@@ -18,7 +18,7 @@
     },
     "ss1":
     {
-        "double_201":
+        "double 1":
         {
             "value": "2.234",
             "default_value": "1.234",
@@ -28,7 +28,7 @@
         },
         "ss2":
         {
-            "double_202":
+            "double 2":
             {
                 "value": "5.321",
                 "default_value": "4.321",
@@ -38,25 +38,25 @@
             }
         }
     },
-    "Testing_25testing":
+    "Testing%testing":
     {
-        "string_26list":
+        "string&list":
         {
             "value": "< & > ; \/",
             "default_value": "< & > ; \/",
             "documentation": "docs 1",
             "pattern": "4",
             "pattern_description": "[Anything]"
         },
-        "int_2aint":
+        "int*int":
         {
             "value": "2",
             "default_value": "2",
             "documentation": "",
             "pattern": "5",
             "pattern_description": "[Integer range -2147483648...2147483647 (inclusive)]"
         },
-        "double_2bdouble":
+        "double+double":
         {
             "value": "7.1415926",
             "default_value": "6.1415926",