.. index:: single: jwt_helpers
.. _jwt_helpers/0:

.. rst-class:: right

**category**

``jwt_helpers``
===============

Internal shared helpers for the jwt library.

| **Availability:** 
|    ``logtalk_load(jwt(loader))``

| **Author:** Paulo Moura
| **Version:** 1:0:0
| **Date:** 2026-07-06

| **Compilation flags:**
|    ``static``


| **Extends:**
|    ``public`` :ref:`options <options/0>`
| **Uses:**
|    :ref:`base64url_no_padding <base64url_no_padding/0>`
|    :ref:`list <list/0>`

| **Remarks:**
|    (none)

| **Inherited public predicates:**
|     :ref:`options_protocol/0::check_option/1`  :ref:`options_protocol/0::check_options/1`  :ref:`options_protocol/0::default_option/1`  :ref:`options_protocol/0::default_options/1`  :ref:`options_protocol/0::option/2`  :ref:`options_protocol/0::option/3`  :ref:`options_protocol/0::valid_option/1`  :ref:`options_protocol/0::valid_options/1`  

.. contents::
   :local:
   :backlinks: top

Public predicates
-----------------

(no local declarations; see entity ancestors if any)

Protected predicates
--------------------

.. index:: json_member/3
.. _jwt_helpers/0::json_member/3:

``json_member/3``
^^^^^^^^^^^^^^^^^

Enumerates JSON object member values for a given key.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``json_member(Key,Object,Value)``
| **Mode and number of proofs:**
|    ``json_member(+atom,+term,-term)`` - ``zero_or_more``


------------

.. index:: json_member_default/4
.. _jwt_helpers/0::json_member_default/4:

``json_member_default/4``
^^^^^^^^^^^^^^^^^^^^^^^^^

Returns a JSON object member value or a default when the key is absent.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``json_member_default(Key,Object,Default,Value)``
| **Mode and number of proofs:**
|    ``json_member_default(+atom,+term,+term,-term)`` - ``one``


------------

.. index:: json_object_pairs/2
.. _jwt_helpers/0::json_object_pairs/2:

``json_object_pairs/2``
^^^^^^^^^^^^^^^^^^^^^^^

Extracts the key-value pairs from a JSON object term.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``json_object_pairs(Object,Pairs)``
| **Mode and number of proofs:**
|    ``json_object_pairs(+term,-list(compound))`` - ``zero_or_one``


------------

.. index:: json_object/1
.. _jwt_helpers/0::json_object/1:

``json_object/1``
^^^^^^^^^^^^^^^^^

Validates that a JSON term is an object without duplicate member names.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``json_object(Object)``
| **Mode and number of proofs:**
|    ``json_object(+term)`` - ``one_or_error``

| **Exceptions:**
|    ``Object`` is not a JSON object or contains duplicate member names:
|        ``domain_error(jwt_json_object,Object)``


------------

.. index:: pair_key_value/3
.. _jwt_helpers/0::pair_key_value/3:

``pair_key_value/3``
^^^^^^^^^^^^^^^^^^^^

Extracts the key and value from a JSON pair compound term.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``pair_key_value(Pair,Key,Value)``
| **Mode and number of proofs:**
|    ``pair_key_value(+compound,-term,-term)`` - ``one``


------------

.. index:: base64url_atom_bytes/2
.. _jwt_helpers/0::base64url_atom_bytes/2:

``base64url_atom_bytes/2``
^^^^^^^^^^^^^^^^^^^^^^^^^^

Converts between unpadded Base64URL atoms and byte lists.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``base64url_atom_bytes(Atom,Bytes)``
| **Mode and number of proofs:**
|    ``base64url_atom_bytes(+atom,-list(byte))`` - ``one_or_error``
|    ``base64url_atom_bytes(-atom,+list(byte))`` - ``one_or_error``

| **Exceptions:**
|    ``Atom`` is a variable or the sink is a variable:
|        ``instantiation_error``
|    ``Atom`` is neither a variable nor a valid Base64URL source term:
|        ``domain_error(base64url_source,codes(Codes))``
|    ``Bytes`` cannot be encoded in the requested Base64URL sink representation:
|        ``domain_error(base64url_sink,codes(Codes))``
|    ``Atom`` contains Base64URL data with characters outside the Base64URL alphabet:
|        ``representation_error(base64)``


------------

.. index:: atom_bytes/2
.. _jwt_helpers/0::atom_bytes/2:

``atom_bytes/2``
^^^^^^^^^^^^^^^^

Converts between an atom and its byte list representation.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``atom_bytes(Atom,Bytes)``
| **Mode and number of proofs:**
|    ``atom_bytes(+atom,-list(byte))`` - ``one``
|    ``atom_bytes(-atom,+list(byte))`` - ``one``


------------

.. index:: bytes_atom/2
.. _jwt_helpers/0::bytes_atom/2:

``bytes_atom/2``
^^^^^^^^^^^^^^^^

Converts a byte list into an atom.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``bytes_atom(Bytes,Atom)``
| **Mode and number of proofs:**
|    ``bytes_atom(+list(byte),-atom)`` - ``one``


------------

.. index:: atom_list/1
.. _jwt_helpers/0::atom_list/1:

``atom_list/1``
^^^^^^^^^^^^^^^

Validates that a list contains only atoms.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``atom_list(Atoms)``
| **Mode and number of proofs:**
|    ``atom_list(+list(atom))`` - ``zero_or_one``


------------

Private predicates
------------------

(no local declarations; see entity ancestors if any)

Operators
---------

(none)