Integrated generic resource: Representation structures ISO 10303-43:2021(E)
© ISO

Cover page
Table of contents
Copyright
Foreword
Introduction
1 Scope
2 Normative references
3 Terms, definitions and abbreviated terms
    3.1 Terms and definitions
    3.2 Abbreviated terms

4 Representation
   4.1 General
   4.2 Fundamental concepts and assumptions
   4.3 Representation type definitions
   4.4 Representation entity definitions
   4.5 Representation function definitions

A Short names of entities
B Information object registration
C Computer interpretable listings
D EXPRESS-G diagrams
E Change history
Bibliography
Index

(*
ISO/TC 184/SC 4/WG 12 N10587 - ISO 10303-43 Representation structures - EXPRESS
Supersedes ISO/TC 184/SC 4/WG 12 N9770
*)



SCHEMA representation_schema;

REFERENCE FROM basic_attribute_schema   -- ISO 10303-41
  (description_attribute,
   description_attribute_select,
   get_description_value,
   get_id_value,
   id_attribute,
   id_attribute_select);

REFERENCE FROM measure_schema   -- ISO 10303-41
  (measure_value,
   measure_with_unit);

REFERENCE FROM support_resource_schema   -- ISO 10303-41
  (bag_to_set,
   identifier,
   label,
   text);


TYPE compound_item_definition = SELECT
   (list_representation_item,
    set_representation_item);
END_TYPE;

TYPE founded_item_select = SELECT
   (founded_item,
    representation_item);
END_TYPE;

TYPE list_representation_item = LIST[1:?] OF representation_item;
END_TYPE;

TYPE representation_or_representation_reference = SELECT
   (representation,
    representation_reference);
END_TYPE;

TYPE rs_description_attribute_select = SELECT BASED_ON description_attribute_select WITH
   (representation);
END_TYPE;

TYPE rs_id_attribute_select = SELECT BASED_ON id_attribute_select WITH
   (representation);
END_TYPE;

TYPE set_item_defined_transformation = SET[1:?] OF item_defined_transformation;
END_TYPE;

TYPE set_representation_item = SET[1:?] OF representation_item;
END_TYPE;

TYPE transformation = SELECT
   (item_defined_transformation,
    functionally_defined_transformation,
    set_item_defined_transformation);
END_TYPE;

ENTITY binary_representation_item
  SUBTYPE OF (representation_item);
  binary_value : BINARY;
END_ENTITY;

ENTITY bytes_representation_item
  SUBTYPE OF (binary_representation_item);
DERIVE
  no_of_bytes : INTEGER := BLENGTH(SELF\binary_representation_item.binary_value) DIV 8;
WHERE
  WR1: BLENGTH(SELF\binary_representation_item.binary_value) MOD 8 = 0;
END_ENTITY;

ENTITY compound_representation_item
  SUBTYPE OF (representation_item);
  item_element : compound_item_definition;
END_ENTITY;

ENTITY definitional_representation
  SUBTYPE OF (representation);
WHERE
  WR1: 'REPRESENTATION_SCHEMA.PARAMETRIC_REPRESENTATION_CONTEXT' IN TYPEOF (SELF\representation.context_of_items );
END_ENTITY;

ENTITY definitional_representation_relationship
  SUBTYPE OF (representation_relationship);
WHERE
  WR1: acyclic_representation_relationship(SELF, [SELF\representation_relationship.rep_2], 'REPRESENTATION_SCHEMA.'+'REPRESENTATION');
END_ENTITY;

ENTITY definitional_representation_relationship_with_same_context
  SUBTYPE OF (definitional_representation_relationship);
WHERE
  WR1: SELF\representation_relationship.rep_1.context_of_items :=: SELF\representation_relationship.rep_2.context_of_items;
END_ENTITY;

ENTITY founded_item;
DERIVE
  users : SET[0:?] OF founded_item_select := using_items(SELF,[]);
WHERE
  WR1: SIZEOF(users) > 0;
  WR2: NOT(SELF IN users);
END_ENTITY;

ENTITY functionally_defined_transformation;
  name : label;
  description : OPTIONAL text;
END_ENTITY;

ENTITY global_uncertainty_assigned_context
  SUBTYPE OF (representation_context);
  uncertainty : SET[1:?] OF uncertainty_measure_with_unit;
END_ENTITY;

ENTITY item_defined_transformation;
  name : label;
  description : OPTIONAL text;
  transform_item_1 : representation_item;
  transform_item_2 : representation_item;
END_ENTITY;

ENTITY mapped_item
  SUBTYPE OF (representation_item);
  mapping_source : representation_map;
  mapping_target : representation_item;
WHERE
  WR1: acyclic_mapped_representation(SELF);
END_ENTITY;

ENTITY parametric_representation_context
  SUBTYPE OF (representation_context);
END_ENTITY;

ENTITY representation;
  name : label;
  items : SET[1:?] OF representation_item;
  context_of_items : representation_context;
DERIVE
  id : identifier := get_id_value (SELF);
  description : text := get_description_value (SELF);
WHERE
  WR1: SIZEOF (USEDIN (SELF, 'BASIC_ATTRIBUTE_SCHEMA.' + 'ID_ATTRIBUTE.IDENTIFIED_ITEM')) <= 1;
  WR2: SIZEOF (USEDIN (SELF, 'BASIC_ATTRIBUTE_SCHEMA.' + 'DESCRIPTION_ATTRIBUTE.DESCRIBED_ITEM')) <= 1;
END_ENTITY;

ENTITY representation_context;
  context_identifier : identifier;
  context_type : text;
INVERSE
  representations_in_context : SET[1:?] OF representation FOR context_of_items;
END_ENTITY;

ENTITY representation_context_reference;
  context_identifier : identifier;
INVERSE
  representations_in_context : SET[1:?] OF representation_reference FOR context_of_items;
END_ENTITY;

ENTITY representation_item
  SUPERTYPE OF (ONEOF (binary_representation_item,
                       compound_representation_item,
                       mapped_item,
                       value_representation_item));
  name : label;
WHERE
  WR1: SIZEOF(using_representations(SELF)) > 0;
END_ENTITY;

ENTITY representation_item_relationship;
  name : label;
  description : OPTIONAL text;
  relating_representation_item : representation_item;
  related_representation_item : representation_item;
END_ENTITY;

ENTITY representation_map;
  mapping_origin : representation_item;
  mapped_representation : representation;
INVERSE
  map_usage : SET[1:?] OF mapped_item FOR mapping_source;
WHERE
  WR1: item_in_context(mapping_origin, mapped_representation\representation.context_of_items);
END_ENTITY;

ENTITY representation_reference;
  id : identifier;
  context_of_items : representation_context_reference;
END_ENTITY;

ENTITY representation_relationship;
  name : label;
  description : OPTIONAL text;
  rep_1 : representation_or_representation_reference;
  rep_2 : representation_or_representation_reference;
END_ENTITY;

ENTITY representation_relationship_with_transformation
  SUBTYPE OF (representation_relationship);
  transformation_operator : transformation;
WHERE
  WR1: SELF\representation_relationship.rep_1.context_of_items :<>: SELF\representation_relationship.rep_2.context_of_items;
  WR2: NOT('REPRESENTATION_SCHEMA.ITEM_DEFINED_TRANSFORMATION' IN TYPEOF(transformation_operator)) OR (SELF\representation_relationship.rep_1 IN using_representations(transformation_operator\item_defined_transformation.transform_item_1)) AND (SELF\representation_relationship.rep_2 IN using_representations(transformation_operator\item_defined_transformation.transform_item_2));
END_ENTITY;

ENTITY uncertainty_assigned_representation
  SUBTYPE OF (representation);
  uncertainty : SET[1:?] OF uncertainty_measure_with_unit;
END_ENTITY;

ENTITY uncertainty_measure_with_unit
  SUBTYPE OF (measure_with_unit);
  name : label;
  description : OPTIONAL text;
WHERE
  WR1: valid_measure_value (SELF\measure_with_unit.value_component);
END_ENTITY;

ENTITY value_representation_item
  SUBTYPE OF (representation_item);
  value_component : measure_value;
WHERE
  WR1: SIZEOF (QUERY (rep <* using_representations (SELF) | NOT ('MEASURE_SCHEMA.GLOBAL_UNIT_ASSIGNED_CONTEXT' IN TYPEOF (rep.context_of_items) ))) = 0;
END_ENTITY;

FUNCTION acyclic_mapped_representation
 (mi : mapped_item) : BOOLEAN;
LOCAL
      rms : SET OF representation_map;
      mis : SET OF mapped_item;
      rs1, rs2 : SET OF representation;
    END_LOCAL;
 
    rs1 := using_representations(mi);
    rs2 := [];
    -- loop as long as there are elements in rs1
    REPEAT WHILE SIZEOF(rs1) > 0; 
      REPEAT i := 1 TO HIINDEX(rs1);
        -- Determine the set of representation_map that reference the parent_set
        rms := bag_to_set(USEDIN(rs1[i], 'REPRESENTATION_SCHEMA.REPRESENTATION_MAP.MAPPED_REPRESENTATION'));
        IF SIZEOF(rms) > 0 THEN
          REPEAT j := 1 TO HIINDEX(rms);
            mis := bag_to_set(USEDIN(rms[i], 'REPRESENTATION_SCHEMA.MAPPED_ITEM.MAPPING_SOURCE'));
            IF SIZEOF(mis) > 0 THEN
              REPEAT j := 1 TO HIINDEX(mis);
                -- check mis members for instance equal with mi. If so then there is a cycle
                IF mis[i] :=: mi THEN
                  RETURN (FALSE);
                END_IF;
                rs2 := rs2 + using_representations(mis[i]);
              END_REPEAT;
            END_IF;
          END_REPEAT;
        END_IF;
      END_REPEAT;
      rs1 := rs2;
      rs2 := [];
    END_REPEAT;
    RETURN (TRUE);
END_FUNCTION;

FUNCTION acyclic_representation_relationship
 (relation : representation_relationship; relatives : SET[1:?] OF representation; specific_relation : STRING) : BOOLEAN;
LOCAL
      x : SET OF representation_relationship;
    END_LOCAL;

    IF relation.rep_1 IN relatives THEN
      RETURN (FALSE);
    END_IF;
    x := QUERY(r <* bag_to_set(USEDIN(relation.rep_1, 'REPRESENTATION_SCHEMA.' + 'REPRESENTATION_RELATIONSHIP.' + 'REP_2')) | specific_relation IN TYPEOF(r));
    REPEAT i := 1 TO HIINDEX(x);
      IF NOT acyclic_representation_relationship(x[i], relatives + relation.rep_1, specific_relation) THEN
        RETURN (FALSE);
      END_IF;
    END_REPEAT;
    RETURN (TRUE);
END_FUNCTION;

FUNCTION get_representations_for_items
 (input : SET[0:?] OF founded_item_select) : SET[0:?] OF representation;
LOCAL
      r_set : SET OF representation := [];
    END_LOCAL;
    REPEAT i := LOINDEX(input) TO HIINDEX(input);
        r_set := r_set + using_representations(input[i]);
    END_REPEAT;
    RETURN (r_set);
END_FUNCTION;

FUNCTION item_in_context
 (item : representation_item; cntxt : representation_context) : BOOLEAN;
LOCAL
      y : BAG OF representation_item;
    END_LOCAL;
    -- If there is one or more representation using both the item
    -- and cntxt return true.
    IF SIZEOF(USEDIN(item,'REPRESENTATION_SCHEMA.REPRESENTATION.ITEMS')
      * cntxt.representations_in_context) > 0 THEN
      RETURN (TRUE);
      -- Determine the bag of representation_items that reference
      -- item
      ELSE y := QUERY(z <* USEDIN (item , '') |
             'REPRESENTATION_SCHEMA.REPRESENTATION_ITEM' IN TYPEOF(z));
        -- Ensure that the bag is not empty
        IF SIZEOF(y) > 0 THEN
        -- For each element in the bag
        REPEAT i := 1 TO HIINDEX(y);
          -- Check to see it is an item in the input cntxt.
          IF item_in_context(y[i], cntxt) THEN
            RETURN (TRUE);
          END_IF;
        END_REPEAT;
      END_IF;
    END_IF;
    -- Return false when all possible branches have been checked
    -- with no success.
    RETURN (FALSE);
END_FUNCTION;

FUNCTION using_items
 (item : founded_item_select; checked_items : SET[0:?] OF founded_item_select) : SET[0:?] OF founded_item_select;
LOCAL
      new_check_items    : SET OF founded_item_select;
      result_items       : SET OF founded_item_select;
      next_items         : SET OF founded_item_select;
    END_LOCAL;
    result_items := [];
    new_check_items := checked_items + item;
    -- Find the set of representation_items or founded_items
    -- in which item is used directly.
    next_items := QUERY(z <* bag_to_set( USEDIN(item , '')) |
      ('REPRESENTATION_SCHEMA.REPRESENTATION_ITEM' IN TYPEOF(z)) OR
      ('REPRESENTATION_SCHEMA.FOUNDED_ITEM'        IN TYPEOF(z)));
    -- If the set of next_items is not empty;
    IF SIZEOF(next_items) > 0 THEN
      -- For each element in the set, find the using_items recursively
      REPEAT i := 1 TO HIINDEX(next_items);
        -- Check for loop in data model, i.e. one of the next_items
        -- occurred earlier in the set of check_items;
        IF NOT(next_items[i] IN new_check_items) THEN
          result_items := result_items + next_items[i] +
                          using_items(next_items[i],new_check_items);
        END_IF;
      END_REPEAT;
    END_IF;
    -- return the set of representation_items or founded_items
    -- in which the input item is used directly and indirectly.
    RETURN (result_items);
END_FUNCTION;

FUNCTION using_representations
 (item : founded_item_select) : SET[0:?] OF representation;
LOCAL
      results            : SET OF representation;
      result_bag         : BAG OF representation;
      intermediate_items : SET OF founded_item_select;
    END_LOCAL;
    -- Find the representations in which the item is used and add to the
    -- results set.
    results := [];
    result_bag := USEDIN(item,'REPRESENTATION_SCHEMA.REPRESENTATION.ITEMS');
    IF SIZEOF(result_bag) > 0 THEN
      REPEAT i := 1 TO HIINDEX(result_bag);
        results := results + result_bag[i];
      END_REPEAT;
    END_IF;
    -- Find all representation_items or founded_items
    -- by which item is referenced directly or indirectly.
    intermediate_items := using_items(item,[]);
    -- If the set of intermediate items is not empty;
    IF SIZEOF(intermediate_items) > 0 THEN
      -- For each element in the set, add the
      -- representations of that element.
      REPEAT i := 1 TO HIINDEX(intermediate_items);
        result_bag := USEDIN(intermediate_items[i],
                      'REPRESENTATION_SCHEMA.REPRESENTATION.ITEMS');
        IF SIZEOF(result_bag) > 0 THEN
          REPEAT j := 1 TO HIINDEX(result_bag);
            results := results + result_bag[j];
          END_REPEAT;
        END_IF;
      END_REPEAT;
    END_IF;
    -- Return the set of representation in which the input item is
    -- used directly and indirectly (through intervening
    -- representation_items or founded items).
    RETURN (results);
END_FUNCTION;

FUNCTION valid_measure_value
 (m : measure_value) : BOOLEAN;
IF ('REAL' IN TYPEOF (m)) THEN
    RETURN (m > 0.0);
    ELSE
     IF ('INTEGER' IN TYPEOF (m)) THEN
      RETURN (m > 0);
      ELSE
        RETURN (TRUE);
      END_IF;
    END_IF;
END_FUNCTION;

END_SCHEMA;  -- representation_schema


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