json_to_storage.cc

Go to the documentation of this file.

/*
 * json_to_storage.cc
 *
 *  Created on: May 7, 2012
 *      Author: jb
 */

#include <boost/cstdint.hpp>
#include <limits>
#include <boost/iostreams/device/file.hpp>
#include <boost/iostreams/filtering_stream.hpp>

#include "json_to_storage.hh"
#include "input/comment_filter.hh"

#include "json_spirit/json_spirit_error_position.h"

namespace Input {
using namespace std;
using namespace internal;



/********************************************
 * Implementation of  internal::JSONPath
 */


JSONPath::JSONPath(const Node& root_node)
{
    path_.push_back( make_pair( (int)(-1), string("/") ) );
    nodes_.push_back( &root_node );
}

const JSONPath::Node * JSONPath::down(unsigned int index)
{
    const Node * head_node = nodes_.back();
    const json_spirit::mArray &array = head_node->get_array(); // the type should be checked in make_storage

    if (  index >= array.size()) return NULL;
    path_.push_back( make_pair( index, string("") ) );
    nodes_.push_back( &( array[index] ) );

    return nodes_.back();
}


const JSONPath::Node * JSONPath::down(const string& key)
{
    const Node * head_node = nodes_.back();
    const json_spirit::mObject &obj = head_node->get_obj(); // the type should be checked in make_storage

    json_spirit::mObject::const_iterator it = obj.find(key);
    if (it == obj.end()) {
        return NULL;
    } else {
        path_.push_back( make_pair( (int)(-1), key) );
        nodes_.push_back( &( it->second ) );
    }
    return nodes_.back();
}


void JSONPath::up()
{
    if (path_.size() > 1) {
        path_.pop_back();
        nodes_.pop_back();
    }
}

void JSONPath::go_to_root() {
    path_.resize(1);
    nodes_.resize(1);
}


bool JSONPath::get_ref_from_head(string & ref_address)
{
    const Node * head_node = nodes_.back();
    if (head_node->type() != json_spirit::obj_type) return false;
    const json_spirit::mObject &obj = head_node->get_obj();
    if (obj.size() != 1) return false;
    if (obj.begin()->first != "REF") return false;

    const Node &ref_node = obj.begin()->second;
    if (ref_node.type() != json_spirit::str_type) {
        THROW( ExcRefOfWrongType() << EI_ErrorAddress(*this) );

    }
    ref_address = ref_node.get_str();
    return true;
}


/**
 * This returns path to reference given by address in ref_address.
 *
 */
JSONPath JSONPath::find_ref_node(const string& ref_address)
{
    namespace ba = boost::algorithm;

    JSONPath ref_path(*this);

    string::size_type pos = 0;
    string::size_type new_pos = 0;
    string address = ref_address + '/';
    string tmp_str;
    bool relative_ref = false;

    std::set<string>::iterator it = previous_references_.find(ref_address);
    if (it == previous_references_.end()) {
        ref_path.previous_references_.insert(ref_address);
    } else {
        THROW( ExcReferenceNotFound() << EI_RefAddress(*this) << EI_ErrorAddress(ref_path) << EI_RefStr(ref_address)
               << EI_Specification("cannot follow reference") );
    }

    while ( ( new_pos=address.find('/',pos) ) != string::npos ) {
        tmp_str = address.substr(pos, new_pos - pos);
        if (pos==0 && tmp_str == "") {
            // absolute path
            ref_path.go_to_root();

        } else if ( ba::all( tmp_str, ba::is_digit()) ) {
            // integer == index in array
            if (ref_path.head() -> type() != json_spirit::array_type) {
                THROW( ExcReferenceNotFound() << EI_RefAddress(*this) << EI_ErrorAddress(ref_path) << EI_RefStr(ref_address)
                        << EI_Specification("there should be Array") );
            }

            if ( ref_path.down( atoi(tmp_str.c_str()) ) == NULL) {
                THROW( ExcReferenceNotFound() << EI_RefAddress(*this) << EI_ErrorAddress(ref_path) << EI_RefStr(ref_address)
                        << EI_Specification("index out of size of Array") );
            }

        } else if (tmp_str == "..") {
            relative_ref = true;
            if (ref_path.level() <= 0 ) {
                THROW( ExcReferenceNotFound() << EI_RefAddress(*this) << EI_ErrorAddress(ref_path) << EI_RefStr(ref_address)
                        << EI_Specification("can not go up from root") );
            }
            ref_path.up();

        } else {
            if (ref_path.head() -> type() != json_spirit::obj_type)
                THROW( ExcReferenceNotFound() << EI_RefAddress(*this) << EI_ErrorAddress(ref_path) << EI_RefStr(ref_address)
                        << EI_Specification("there should be Record") );
            if ( ref_path.down(tmp_str) == NULL )
                THROW( ExcReferenceNotFound() << EI_RefAddress(*this) << EI_ErrorAddress(ref_path) << EI_RefStr(ref_address)
                        << EI_Specification("key '"+tmp_str+"' not found") );
        }
        pos = new_pos+1;
    }
    if (relative_ref) {
        xprintf(Msg, "Referencing '%s' to '%s'.\n", this->str().c_str(), ref_path.str().c_str());
    }
    return ref_path;
}



void JSONPath::output(ostream &stream) const {
    if (level() == 0) {
        stream << "/";
        return;
    }

    for(vector< pair<int, string> >::const_iterator it = path_.begin()+1; it != path_.end(); ++it) {
        if ( it->first < 0 ) {
            stream << "/" << it->second;
        } else {
            stream << "/" << it->first;
        }
    }
}



string JSONPath::str() {
    stringstream ss;
    output(ss);
    return ss.str();
}



void JSONPath::put_address() {
    previous_references_.insert(str());
}



std::ostream& operator<<(std::ostream& stream, const JSONPath& path) {
    path.output(stream);
    return stream;
}


/********************************************
 * Implementation of public part of JSONToStorage
 */

JSONToStorage::JSONToStorage()
: storage_(nullptr),
  root_type_(nullptr)
{
    /* from json_spirit_value.hh:
     * enum Value_type{ obj_type, array_type, str_type, bool_type, int_type, real_type, null_type };
     */
    json_type_names.push_back("JSON object");
    json_type_names.push_back("JSON array");
    json_type_names.push_back("JSON string");
    json_type_names.push_back("JSON bool");
    json_type_names.push_back("JSON int");
    json_type_names.push_back("JSON real");
    json_type_names.push_back("JSON null");
}



JSONToStorage::JSONToStorage(istream &in, const Type::TypeBase &root_type)
: JSONToStorage()
{
    read_stream(in,root_type);
}



JSONToStorage::JSONToStorage( const string &str, const Type::TypeBase &root_type)
: JSONToStorage()
{
    try {
        istringstream is(str);
        read_stream(is, root_type);
    } catch (ExcNotJSONFormat &e) {
        e << EI_File("STRING: "+str); throw;
    }
}



void JSONToStorage::read_stream(istream &in, const Type::TypeBase &root_type)
{
    namespace io = boost::iostreams;
    ASSERT(storage_==nullptr," ");

    // finish all lazy input types
    Input::Type::TypeBase::lazy_finish();

    io::filtering_istream filter_in;

    filter_in.push(uncommenting_filter());
    filter_in.push(in);

    JSONPath::Node node;


    try {
        json_spirit::read_or_throw( filter_in, node);
    } catch (json_spirit::Error_position &e ) {
        THROW( ExcNotJSONFormat() << EI_JSONLine(e.line_) << EI_JSONColumn(e.column_) << EI_JSONReason(e.reason_));
    }

    JSONPath root_path(node);

    root_type_ = &root_type;
    storage_ = make_storage(root_path, root_type_);

    ASSERT(  storage_ != nullptr, "Internal error in JSON reader, the storage pointer is NULL after reading the stream.\n");
}






/********************************************
 * Implementation of private part of JSONToStorage - make_storage dispatch
 */


StorageBase * JSONToStorage::make_storage(JSONPath &p, const Type::TypeBase *type)
{
    ASSERT(type != NULL, "Can not dispatch, NULL pointer to TypeBase.\n");

    // first check reference
    string ref_address;
    if (p.get_ref_from_head(ref_address)) {
        // todo: mark passed references and check cyclic references

        // dereference and take data from there
        JSONPath ref_path = p.find_ref_node(ref_address);
        return make_storage( ref_path, type );
    }

    // return Null storage if there is null on the current location
    if (p.head()->type() == json_spirit::null_type)
        return new StorageNull();

    // dispatch types
    if (typeid(*type) == typeid(Type::Record)) {
        return make_storage(p, static_cast<const Type::Record *>(type) );
    } else
    if (typeid(*type) == typeid(Type::Array)) {
        return make_storage(p, static_cast<const Type::Array *>(type) );
    } else
    if (typeid(*type) == typeid(Type::Integer)) {
        return make_storage(p, static_cast<const Type::Integer *>(type) );
    } else
    if (typeid(*type) == typeid(Type::Double)) {
        return make_storage(p, static_cast<const Type::Double *>(type) );
    } else
    if (typeid(*type) == typeid(Type::Bool)) {
        return make_storage(p, static_cast<const Type::Bool *>(type) );
    } else
    if (typeid(*type) == typeid(Type::Selection)) {
        return make_storage(p, static_cast<const Type::Selection *>(type) );
    } else {
        const Type::AbstractRecord * abstract_record_type = dynamic_cast<const Type::AbstractRecord *>(type);
        if (abstract_record_type != NULL ) return make_storage(p, abstract_record_type );

        const Type::String * string_type = dynamic_cast<const Type::String *>(type);
        if (string_type != NULL ) return make_storage(p, string_type );

        // default -> error
        xprintf(Err,"Unknown descendant of TypeBase class, name: %s\n", typeid(type).name());
    }

    return new StorageNull();
}


StorageBase * JSONToStorage::make_storage(JSONPath &p, const Type::Record *record)
{
    if (p.head()->type() == json_spirit::obj_type) {
        const json_spirit::mObject & j_map = p.head()->get_obj();
        std::set<string> keys_to_process;
        json_spirit::mObject::const_iterator map_it;
        std::set<string>::iterator set_it;

        for( map_it = j_map.begin(); map_it != j_map.end(); ++map_it) {
           keys_to_process.insert(map_it->first);
        }

        /*Type::Record::KeyIter key_it;
        if ( record->has_key_iterator("TYPE", key_it) && record->auto_conversion_key_iter() != record->end() ) {
            JSONPath type_path(p);
            if (type_path.down( "TYPE" ) != NULL) {
                try {
                    if ( type_path.head()->get_str() != record->type_name() ) {
                        xprintf(UsrErr, "Invalid value of TYPE key of record %s.", record->type_name().c_str());
                    }
                    make_storage(type_path, key_it->type_.get() )->get_int();
                } catch(Type::Selection::ExcSelectionKeyNotFound &e) {
                    return record_automatic_conversion(p, record);
                }
            }
            else {  // automatic conversion
                return record_automatic_conversion(p, record);
            }
        }*/

        StorageArray *storage_array = new StorageArray(record->size());
        // check individual keys
        for( Type::Record::KeyIter it= record->begin(); it != record->end(); ++it) {
            // remove processed key from keys_to_process
            set_it = keys_to_process.find(it->key_);
            if (set_it != keys_to_process.end()) {
                keys_to_process.erase(set_it);
            }

            if (p.down(it->key_) != NULL) {
                // key on input => check & use it
                storage_array->new_item(it->key_index, make_storage(p, it->type_.get()) );
                p.up();
            } else {
                // key not on input
                if (it->default_.is_obligatory() ) {
                    THROW( ExcInputError() << EI_Specification("Missing obligatory key '"+ it->key_ +"'.")
                            << EI_ErrorAddress(p) << EI_InputType(record->desc()) );
                } else if (it->default_.has_value_at_declaration() ) {
                   storage_array->new_item(it->key_index,
                           make_storage_from_default( it->default_.value(), it->type_.get() ) );
                } else { // defalut - optional or default at read time
                    // set null
                    storage_array->new_item(it->key_index, new StorageNull() );
                }
            }
        }

        for( set_it = keys_to_process.begin(); set_it != keys_to_process.end(); ++set_it) {
            xprintf(Warn, "Unprocessed key '%s' in record '%s'.\n", (*set_it).c_str(), p.str().c_str() );
        }

        return storage_array;

    } else { // automatic conversion
        return record_automatic_conversion(p, record);
    }
    // possibly construction of reduced record
}


StorageBase * JSONToStorage::record_automatic_conversion(JSONPath &p, const Type::Record *record)
{
    Type::Record::KeyIter auto_key_it = record->auto_conversion_key_iter();
    if ( auto_key_it != record->end() ) {
        try {
            StorageArray *storage_array = new StorageArray(record->size());
            for( Type::Record::KeyIter it= record->begin(); it != record->end(); ++it) {
                if ( it == auto_key_it ) {
                    // one key is initialized by input
                    storage_array->new_item(it->key_index, make_storage(p, it->type_.get()) );
                } else if (it->default_.has_value_at_declaration() ) {
                    // other key from default values
                    storage_array->new_item(it->key_index,
                            make_storage_from_default( it->default_.value(), it->type_.get() ) );
                 } else { // defalut - optional or default at read time
                     ASSERT( ! it->default_.is_obligatory() ,
                             "Obligatory key: '%s' in auto-convertible record, wrong check during finish().", it->key_.c_str());
                     // set null
                     storage_array->new_item(it->key_index, new StorageNull() );
                 }
            }

            return storage_array;
        } catch (ExcInputError &e ) {
            THROW( ExcAutomaticConversionError() << EI_RecordName(record->type_name()) << EI_InputErrorMessage(e.what()) );
        }

    } else {
        THROW( ExcInputError() << EI_Specification("The value should be 'JSON object', but we found: ")
                << EI_ErrorAddress(p) << EI_JSON_Type( json_type_names[ p.head()->type() ] ) << EI_InputType( record->desc()) );
    }

    return NULL;
}



StorageBase * JSONToStorage::make_storage(JSONPath &p, const Type::AbstractRecord *abstr_rec)
{
    if (p.head()->type() == json_spirit::obj_type) {

        JSONPath type_path(p);
        if ( type_path.down("TYPE") == NULL ) {
            if ( ! abstr_rec->begin()->default_.has_value_at_declaration() ) {
                THROW( ExcInputError() << EI_Specification("Missing key 'TYPE' in AbstractRecord.") << EI_ErrorAddress(p) << EI_InputType(abstr_rec->desc()) );
            } else { // auto conversion
                return abstract_rec_automatic_conversion(p, abstr_rec);
            }
        } else {
            try {
                // convert to base type to force type dispatch and reference chatching
                const Type::TypeBase * type_of_type = &( abstr_rec->get_type_selection() );
                unsigned int descendant_index = make_storage(type_path, type_of_type )->get_int();
                return make_storage(p, &( abstr_rec->get_descendant(descendant_index) ) );
            } catch(Type::Selection::ExcSelectionKeyNotFound &e) {

                THROW( ExcInputError() << EI_Specification("Wrong TYPE='"+Type::EI_KeyName::ref(e)+"' of AbstractRecord.") << EI_ErrorAddress(p) << EI_InputType(abstr_rec->desc()) );
            }
        }
    } else {
        if ( ! abstr_rec->begin()->default_.has_value_at_declaration() ) {
            THROW( ExcInputError() << EI_Specification("The value should be 'JSON object', but we found: ")
                << EI_ErrorAddress(p) << EI_JSON_Type( json_type_names[ p.head()->type() ] ) << EI_InputType(abstr_rec->desc()) );
        } else { // auto conversion
            return abstract_rec_automatic_conversion(p, abstr_rec);
        }
    }

    return NULL;
}



StorageBase * JSONToStorage::abstract_rec_automatic_conversion(JSONPath &p, const Type::AbstractRecord *abstr_rec)
{
    // perform automatic conversion
    const Type::Record *default_child = abstr_rec->get_default_descendant();
    if (! default_child) THROW(ExcInputError()
            << EI_Specification("Auto conversion of AbstractRecord not allowed.\n")
            << EI_ErrorAddress(p)
            << EI_InputType(abstr_rec->desc())
            );
    return make_storage(p, default_child );
}



StorageBase * JSONToStorage::make_storage(JSONPath &p, const Type::Array *array)
{

    if (p.head()->type() == json_spirit::array_type) {
        const json_spirit::mArray & j_array = p.head()->get_array();
        if ( array->match_size( j_array.size() ) ) {
          // copy the array and check type of values
          StorageArray *storage_array = new StorageArray(j_array.size());
          for( unsigned int idx=0; idx < j_array.size(); idx++)  {
              p.down(idx);
              const Type::TypeBase &sub_type = array->get_sub_type();
              storage_array->new_item(idx, make_storage(p, &sub_type) );
              p.up();
          }
          return storage_array;

        } else {
            THROW( ExcInputError()
                    << EI_Specification("Do not fit into size limits of the Array.")
                    << EI_ErrorAddress(p) << EI_InputType(array->desc()) );
        }
    } else {
        // try automatic conversion to array with one element
        if ( array->match_size( 1 ) ) {
            StorageArray *storage_array = new StorageArray(1);
            const Type::TypeBase &sub_type = array->get_sub_type();
            storage_array->new_item(0, make_storage(p, &sub_type) );

            return storage_array;
        } else {
            THROW( ExcInputError() << EI_Specification("Automatic conversion to array not allowed. The value should be 'JSON array', but we found: ")
                    << EI_ErrorAddress(p) << EI_JSON_Type( json_type_names[ p.head()->type() ] ) << EI_InputType(array->desc()) );
        }
    }

    return NULL;
}



StorageBase * JSONToStorage::make_storage(JSONPath &p, const Type::Selection *selection)
{
    string item_name;
    if (p.head()->type() == json_spirit::str_type) {
        try {
            item_name = p.head()->get_str();
            int value = selection->name_to_int( item_name  );
            return new StorageInt( value );
        } catch (Type::Selection::ExcSelectionKeyNotFound &exc) {
            THROW( ExcInputError() << EI_Specification("Wrong value '" + item_name + "' of the Selection.")
                    << EI_ErrorAddress(p) << EI_JSON_Type( "" ) << EI_InputType(selection->desc()) );
        }
    }

    THROW( ExcInputError() << EI_Specification("The value should be 'JSON string', but we found: ")
            << EI_ErrorAddress(p) << EI_JSON_Type( json_type_names[ p.head()->type() ] ) << EI_InputType(selection->desc())  );

    return NULL;
}



StorageBase * JSONToStorage::make_storage(JSONPath &p, const Type::Bool *bool_type)
{
    if (p.head()->type() == json_spirit::bool_type) {
        return new StorageBool( p.head()->get_bool() );
    } else {
        THROW( ExcInputError() << EI_Specification("The value should be 'JSON bool', but we found: ")
                << EI_ErrorAddress(p) << EI_JSON_Type( json_type_names[ p.head()->type() ] ) << EI_InputType(bool_type->desc())  );
    }
    return NULL;
}



StorageBase * JSONToStorage::make_storage(JSONPath &p, const Type::Integer *int_type)
{
    if (p.head()->type() == json_spirit::int_type) {
        boost::int64_t value = p.head()->get_int64();

        if ( value >= std::numeric_limits<int>::min() &&
             value <= std::numeric_limits<int>::max() &&
             int_type->match(value) )
        {
            return new StorageInt( value );
        } else {
            THROW( ExcInputError() << EI_Specification("Value out of bounds.") << EI_ErrorAddress(p) << EI_InputType(int_type->desc()) );
        }

    } else {
        THROW( ExcInputError() << EI_Specification("The value should be 'JSON int', but we found: ")
                << EI_ErrorAddress(p) << EI_JSON_Type( json_type_names[ p.head()->type() ] ) << EI_InputType(int_type->desc()) );

    }
    return NULL;
}



StorageBase * JSONToStorage::make_storage(JSONPath &p, const Type::Double *double_type)
{
    double value;

    auto value_type = p.head()->type();
    if (    value_type== json_spirit::real_type
         || value_type == json_spirit::int_type) {
        value = p.head()->get_real();
    } else {
        THROW( ExcInputError() << EI_Specification("The value should be 'JSON real', but we found: ")
                << EI_ErrorAddress(p) << EI_JSON_Type( json_type_names[ p.head()->type() ] ) << EI_InputType(double_type->desc()) );
    }

    if (double_type->match(value)) {
        return new StorageDouble( value );
    } else {
        THROW( ExcInputError() << EI_Specification("Value out of bounds.") << EI_ErrorAddress(p) << EI_InputType(double_type->desc()) );
    }

    return NULL;
}



StorageBase * JSONToStorage::make_storage(JSONPath &p, const Type::String *string_type)
{
    if (p.head()->type() == json_spirit::str_type) {
        string value = p.head()->get_str();
        if (string_type->match(value))
            return new StorageString( value );
        else
            THROW( ExcInputError() << EI_Specification("Output file can not be given by absolute path: '" + value + "'")
                            << EI_ErrorAddress(p) << EI_JSON_Type("") << EI_InputType(string_type->desc()) );
    } else {
        THROW( ExcInputError() << EI_Specification("The value should be 'JSON string', but we found: ")
                << EI_ErrorAddress(p) << EI_JSON_Type( json_type_names[ p.head()->type() ] ) << EI_InputType(string_type->desc()) );

    }
    return NULL;
}



StorageBase * JSONToStorage::make_storage_from_default(const string &dflt_str, const Type::TypeBase *type) {
    try {
        /*
        // Possible simplification of this method (need default strings to be valid JSON)
        JSONToStorage  tmp_storage(dflt_str, *type);
        return tmp_storage.storage_;
        */

        // an auto-convertible AbstractRecord can be initialized form default value
        const Type::AbstractRecord *a_record = dynamic_cast<const Type::AbstractRecord *>(type);
        if (a_record != NULL ) {
            if (a_record->begin()->default_.has_value_at_declaration() )    // a_record->bagin() ... TYPE key
                return make_storage_from_default( dflt_str, a_record->get_default_descendant() );
            else
                xprintf(PrgErr,"Can not initialize (non-auto-convertible) AbstractRecord '%s' by default value\n", type->type_name().c_str());
        } else
        if (typeid(*type) == typeid(Type::Record) ) {
            // an auto-convertible Record can be initialized form default value
            const Type::Record *record = static_cast<const Type::Record *>(type);
            Type::Record::KeyIter auto_key_it = record->auto_conversion_key_iter();
            if ( auto_key_it != record->end() ) {
                StorageArray *storage_array = new StorageArray(record->size());
                for( Type::Record::KeyIter it= record->begin(); it != record->end(); ++it) {
                    if ( it == auto_key_it ) {
                        // one key is initialized by the record default string
                        storage_array->new_item(it->key_index, make_storage_from_default(dflt_str, it->type_.get()) );
                    } else {

                        ASSERT( ! it->default_.is_obligatory(),
                                "Missing default value for key: '%s' in auto-convertible record, wrong check during finish().", it->key_.c_str());

                        if (it->default_.has_value_at_declaration() ) {
                           storage_array->new_item(it->key_index,
                                   make_storage_from_default( it->default_.value(), it->type_.get() ) );
                        } else { // defalut - optional or default at read time
                            // set null
                            storage_array->new_item(it->key_index, new StorageNull() );
                        }
                    }
                }

                return storage_array;
            } else {
                xprintf(PrgErr,"Can not initialize (non-auto-convertible) Record '%s' by default value\n", type->type_name().c_str());
            }
        } else
        if (typeid(*type) == typeid(Type::Array) ) {
            const Type::Array *array = static_cast<const Type::Array *>(type);
            if ( array->match_size(1) ) {
               // try auto conversion to array
                StorageArray *storage_array = new StorageArray(1);
                const Type::TypeBase &sub_type = array->get_sub_type();
                storage_array->new_item(0, make_storage_from_default(dflt_str, &sub_type) );
                return storage_array;
            } else {
                xprintf(PrgErr,"Can not initialize Array '%s' by default value, size 1 not allowed.\n", type->type_name().c_str());
            }

        } else
        if (typeid(*type) == typeid(Type::Integer)) {
            return new StorageInt( static_cast<const Type::Integer *>(type) ->from_default(dflt_str) );
        } else
        if (typeid(*type) == typeid(Type::Double)) {
            return new StorageDouble( static_cast<const Type::Double *>(type) ->from_default(dflt_str) );
        } else
        if (typeid(*type) == typeid(Type::Bool)) {
            return new StorageBool( static_cast<const Type::Bool *>(type) ->from_default(dflt_str) );
        } else
        if (typeid(*type) == typeid(Type::Selection)) {
                return new StorageInt( static_cast<const Type::Selection *>(type) ->from_default(dflt_str) );
        } else {
            const Type::String * string_type = dynamic_cast<const Type::String *>(type);
            if (string_type != NULL ) return new StorageString( string_type->from_default(dflt_str) );

            // default error
            xprintf(PrgErr,"Can not store default value for type: %s\n", typeid(type).name());
        }


    } catch (Input::Type::ExcWrongDefault & e) {
        // message to distinguish exceptions thrown during Default value check at declaration
        xprintf(Msg, "Wrong default value while reading an input stream:\n");
        e << EI_KeyName("UNKNOWN KEY");
        throw;
    }

    return NULL;
}



} // namespace Input