ListType

ListType

new ListType(parameters)

Description:

  • Specifies a list type, i.e. an strictly ordered container of elements.

    Extends: Type. This class extends Type, with all public methods available.

    Type parameters

    General parameters

    • name: ... The type name. By default the type name is list-of-$itemType.
    • itemType: ... The type elements if any. By default, "value", means any value.

    Parameters for the syntactic projection

    • minLength: ... The minimal number of items in the list. By default 0.
    • maxLength: ... The maximal number of items in the list. By default unbounded (-1).

    Parameters for the cost calculation

    • deleteCost: ... The non-negative deleting cost value.
      • By default uses the getDistance() between the item and an empty data structure.
    • insertCost: ... The non-negative inserting cost value.
      • By default equals to the deleteCost.
    • editCost: ... The non-negative editing cost value.
      • By default uses the getDistance() between each item.

    ListType specification

    Syntactic projection - If the value is empty, it corresponds to an empty list.
    - If the value is not a list, it is encapsulated in a [ value ] singleton.
    - If the list length is not in the (optional) [minLength, maxLength] bounds a message is issued, but the list is neither truncated nor extended.
    - Each list item is syntactically projected.
    Semantic projection - Each list item is semantically projected.
    Distance value - The minimal distance is computed using the Levenshtein distance calculation applied on the list element and delegating the edition cost to the item Type distance computation.
         - The algorithmic complexity order of magnitude is thus quadratic with respect to the list length considering the item type complexity as basic operation.
    - The editing distance can be either:
         - parameterized defining fixed deletion, insertion and editing costs, or
         - parameterized rederiving the cost() function.
    Geodesic path - The geodesic path corresponds to the Wagner-Fischer algorithm shortest path in the matrix distance yielding to the minimal distance computation.
    Comparison - Returns 0 If each element pair compares equal and both lists have the same length.
    - Returns <0 If either the value of the first item that does not match is lower in the left hand side list, or all compared items match but the left hand side list is shorter.
    - Returns >0 If either the value of the first item that does not match is greater in the left hand side list, or all compared items match but the left hand side list is longer.
    Bounds - Considers all list lengths beetwen `minLength` and `maxLength` to calculate the bounds, from the item type bounds.
Parameters:
Name Type Description
parameters JSON | String

The type parameters.

Methods

cost(what, lhs, i, rhs, j) → {double}

Description:

  • Cost function of the editing distance

    • The ListType::cost() implements the deleteCost, insertCost and editCost parameters related cost.
    • A typical re-implementation is of the form:
    class MyListType : public ListType {
../..
  double cost(char what, JSON lhs, unsigned int i, JSON rhs, unsigned int j) const {
   // Implements the MyListType specific features, if appropriate and returns the value
   return ListType::cost(what, lhs, i, rhs, j); // Delegates to the parent implementation otherwise
 }
}
Parameters:
Name Type Description
what char

The editing operation:

  • 'd' : deletion cost for the lhs[i] value.
  • 'i' : insertion cost for the rhs[j] value.
  • 'e' : edition cost to transform the lhs[i] to rhs[j]
lhs Value

The left hand-size value.
i uint

The lhs index.
rhs Value

The right hand-size value.
j uint

The rhs index.
Returns:

The cost value.

Type
double