FA-79509 / Barcode symbology encoding / Member archive

Add-ons are allowed on Code 128 · case 04

Layouts reserve space for an EAN-5 next to a Code 128 symbol that scanners will never read together.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

Input {sym, modules, x_um, addon?}. Quiet zones in X: ean13 11 left / 7 right, upca 9/9, ean8 7/7, code128, code39 and itf14 10/10. Allowed X-dimensions in micrometres: EAN/UPC 264..660 inclusive, code128/code39 >= 190, itf14 >= 495. An EAN-2 (20 modules) or EAN-5 (47 modules) add-on is only allowed on EAN/UPC; it replaces the right quiet zone by a 7-module gap, the add-on and a 5-module trailing quiet zone. Return [total_um, left_quiet_um] or unknown/x-out-of-range/bad-addon.

Why this case matters

Retail, logistics, pharmacy and document workflows depend on encoders that produce exactly the module pattern, code-set switches, separators and quiet zones scanners expect; one misplaced module or separator makes a label unreadable or, worse, scan as different data.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
regression: add-on symbology restriction 0	`[68000, 4000]`	`"bad-addon"`	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.