FA-66722 / Airline fare rule evaluation / Member archive

W and X day codes decoded backwards · case 02

Weekend fares are reported as weekday-only.

Member previewVariant 2 · 3 implementations · 12 checks per implementation

Case contract

Input: a fare basis string. Grammar: RBD letter A-Z (ASCII uppercase, else 'ERR_BASIS'), optional season H|L, optional day code W (WEEKEND) | X (WEEKDAY), optional advance purchase digits of any length (default 0), then two-letter tokens from CH, IN, NR (otherwise or odd length -> 'ERR_TOKEN'). Return {'rbd','season','days','ap','flags'}.

Why this case matters

Fare basis codes pack booking class, season, day-of-week application, advance purchase and passenger/penalty indicators into a positional code.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
full basis	`{"ap": 9, "days": "WEEKEND", "flags": ["NR", "CH"], "rbd": "Q", "season": "L"}`	`{"ap": 9, "days": "WEEKDAY", "flags": ["NR", "CH"], "rbd": "Q", "season": "L"}`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.