orthonym.decomposition.fragment_ranker#

Note

Internal API. Names and behaviour may change between releases.

Fragment seniority ranking for decomposition parent/substituent assignment.

Implements IUPAC seniority-based fragment ranking to determine which fragment becomes the parent structure in decomposition naming. Uses existing seniority.py and functional_groups.py infrastructure – this is a thin wrapper.

Ranking criteria (applied in order until tie-broken): 1. Most principal characteristic groups 2. Most senior principal group type 3. Senior heteroatom: N > O > S 4. Ring system present beats chain-only 5. Most heavy atoms size tiebreaker)

Scores are tuples where LOWER = MORE SENIOR (natural sort order).

orthonym.decomposition.fragment_ranker.score_fragment_seniority(frag_smiles)#

_score_fragment_seniority_impl(), memoised for the life of the process: the score is a pure function of frag_smiles (an RDKit parse, the functional groups it carries and its ring/heavy-atom counts; no provenance, no budget), so one process computes it once per string. ORTHONYM_MEMO=off|verify and ORTHONYM_PROCESS_CACHE=0 bypass the memo exactly as for fg_detect.

orthonym.decomposition.fragment_ranker.rank_fragments(fragments)#

Rank fragment dicts by seniority (most senior first).

Parameters:

fragments (List[Dict]) – List of dicts, each must have a “smiles” key. All other keys are preserved.

Returns:

New list sorted by seniority (most senior first = lowest score).

Return type:

List[Dict]

orthonym.decomposition.fragment_ranker.acid_is_more_senior(acid_smiles, other_smiles)#

Check if the acid fragment is more senior or equal to the other fragment.

Convenience function for engine.py assembly decisions. When this returns False, the other fragment (amine/alkyl) is strictly more senior and should become the parent.

Parameters:

  • acid_smiles (str) – SMILES of the acid-side fragment.

  • other_smiles (str) – SMILES of the other fragment (amine/alkyl).

Returns:

True if acid is more senior or equal (normal assembly). False if other is strictly more senior (reverse assembly).

Return type:

bool