parse_rules_cpp: Low-level C++ parser for association rules

In niarules: Numerical Association Rule Mining using Population-Based Nature-Inspired Algorithms

Low-level C++ parser for association rules

Description

'parse_rules_cpp()' is the Rcpp-exposed engine behind parse_rules. It accepts a data frame of association rules and returns a layout-agnostic parsed structure consisting of an items table and a rules table. This function is exported by Rcpp primarily for internal use and testing.

Usage

parse_rules_cpp(rules_df)

Arguments

rules_df

A data frame with the required columns: Antecedent (character) Consequence (character) Support (numeric) Confidence (numeric) Fitness (numeric; treated as lift by convention)

Details

Parsing rules

• Both LHS and RHS are split on "," or "&" outside of brackets; leading/trailing whitespace is trimmed.

• A single outer brace pair {...} on RHS is stripped if present.

• Supported item syntaxes:

  • Categorical equality: feature = value (value may be quoted).

  • Numeric interval: feature in [lo, hi], (lo, hi], etc.

  • Relational: feature >= x, > x, <= x, < x.

• For relational items, the unused bound is set to NA.

• Fitness is carried through as lift.

Value

A list with two data frames:

items

Columns:

• item_id: integer, 0-based stable ID within this parsed object.

• label: original item string.

• feature: base feature name.

• kind: one of "numeric", "categorical", "set", "unknown".

• category_value: categorical value (quotes removed).

• lo, hi: numeric bounds (may be NA).

• incl_low, incl_high: logical inclusivity flags.

• op: one of "<", "<=", ">", ">=", "=", "in".

• label_long, label_short: preformatted interval labels.

rules

Columns:

• rule_id: 1-based rule index (for display).

• support, confidence, lift: rule-level metrics.

• lhs_item_ids, rhs_item_ids: list-columns of integer vectors of 0-based item_ids.

• antecedent_length, consequent_length: integer lengths of LHS/RHS.

Errors

Throws an error if required columns are missing or have inconsistent lengths.

niarules documentation built on Sept. 15, 2025, 5:08 p.m.