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 code_metrics_utilities

public code_metric

Provides:

logtalk::message_tokens//2

Uses:

list
logtalk
numberlist

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.