deprecated

- The JSON conversion library has been moved to library(json_convert). This stub loads and reexports the new library. Please update your code accordingly.

Re-exported predicates

The following predicates are exported from this file while their implementation is defined in imported modules or non-module files loaded by this module.

 json_object(+Declaration)

Declare a JSON object. The declaration takes the same format as using in record/1 from library(record). E.g.

?- json_object
      point(x:int, y:int, z:int=0).

The type arguments are either types as know to library(error) or functor names of other JSON objects. The constant any indicates an untyped argument. If this is a JSON term, it becomes subject to json_to_prolog/2. I.e., using the type list(any) causes the conversion to be executed on each element of the list.

If a field has a default, the default is used if the field is not specified in the JSON object. Extending the record type definition, types can be of the form (Type1|Type2). The type null means that the field may not be present.

Conversion of JSON to Prolog applies if all non-defaulted arguments can be found in the JSON object. If multiple rules match, the term with the highest arity gets preference.

 prolog_to_json(:Term, -JSONObject) is det

Translate a Prolog application Term into a JSON object term. This transformation is based on :- json_object/1 declarations. If a json_object/1 declaration declares a field of type boolean, commonly used truth-values in Prolog are converted to JSON booleans. Boolean translation accepts one of true, on, 1, @true, false, fail, off or 0, @false.

Errors

- type_error(json_term, X)

- instantiation_error

 json_to_prolog(+JSON, -Term) is det

Translate a JSON term into an application term. This transformation is based on :- json_object/1 declarations. An efficient transformation is non-trivial, but we rely on the assumption that, although the order of fields in JSON terms is irrelevant and can therefore vary a lot, practical applications will normally generate the JSON objects in a consistent order.

If a field in a json_object is declared of type boolean, @true and @false are translated to true or false, the most commonly used Prolog representation for truth-values.