.. index:: single: cogc_metric
.. _cogc_metric/0:

.. rst-class:: right

**object**

``cogc_metric``
===============

Cognitive complexity metric (approximation). For each non-auxiliary predicate, the score contribution is the number of extra clauses (i.e. number of clauses minus one, for multi-clause branching) plus one if the predicate is directly recursive. The entity score is the sum of all predicate contributions. Protocols are not scored as they cannot define predicates.

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

| **Author:** Paulo Moura
| **Version:** 1:0:0
| **Date:** 2026-03-14

| **Compilation flags:**
|    ``static, context_switching_calls``


| **Imports:**
|    ``public`` :ref:`code_metrics_utilities <code_metrics_utilities/0>`
|    ``public`` :ref:`code_metric <code_metric/0>`
| **Provides:**
|    :ref:`logtalk::message_tokens//2 <logtalk/0::message_tokens//2>`
| **Uses:**
|    :ref:`list <list/0>`
|    :ref:`logtalk <logtalk/0>`
|    :ref:`numberlist <numberlist/0>`

| **Remarks:**

   - Limitations: The reflection API does not expose control constructs such as cuts, conditionals, or disjunctions. This metric approximates cognitive complexity using only clause-level branching and direct recursion.
   - Branching: A predicate with N clauses contributes N-1 to the score, representing the N-1 extra choices a reader must track.
   - Recursion: A predicate that directly calls itself (within the same entity) contributes an additional 1 to the score.
   - Score interpretation: The score is represented by a non-negative integer. Higher scores indicate predicates or entities that are harder to understand due to more branching choices or self-recursion. A score of 0 means all predicates are single-clause and non-recursive.
   - Aggregation: File, directory, and library scores are computed by summing the individual entity scores.

| **Inherited public predicates:**
|     :ref:`code_metric/0::all/0`  :ref:`code_metric/0::all/1`  :ref:`code_metric/0::all_score/1`  :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:`code_metric/0::directory/1`  :ref:`code_metric/0::directory/2`  :ref:`code_metric/0::directory_score/2`  :ref:`code_metric/0::entity/1`  :ref:`code_metric/0::entity_score/2`  :ref:`code_metric/0::file/1`  :ref:`code_metric/0::file/2`  :ref:`code_metric/0::file_score/2`  :ref:`code_metric/0::format_entity_score//2`  :ref:`code_metric/0::library/1`  :ref:`code_metric/0::library/2`  :ref:`code_metric/0::library_score/2`  :ref:`options_protocol/0::option/2`  :ref:`options_protocol/0::option/3`  :ref:`code_metric/0::rdirectory/1`  :ref:`code_metric/0::rdirectory/2`  :ref:`code_metric/0::rdirectory_score/2`  :ref:`code_metric/0::rlibrary/1`  :ref:`code_metric/0::rlibrary/2`  :ref:`code_metric/0::rlibrary_score/2`  :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
--------------------

(no local declarations; see entity ancestors if any)

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

(no local declarations; see entity ancestors if any)

Operators
---------

(none)