FA-79608 / Barcode symbology encoding / Member archive

Plain Code 128 scans are parsed as GS1 · case 03

Internal Code 128 labels whose text happens to start with digits are interpreted as GTINs.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

Parse scanner output of a GS1-128 symbol: it must start with the symbology identifier "]C1"; FNC1 separators arrive as GS (0x1D) and redundant separators are skipped. AIs are recognised by the shortest matching prefix among the predefined fixed-length AIs (00:18, 01/02:14, 11/13/15/17:6, 3103:6) and variable AIs (10/21 max 20, 30/37 max 8, 400 max 30). A fixed field must be complete and contain no GS; a variable field runs to the next GS or the end and must have 1..max characters. Return [[ai, value], ...] or an error.

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: symbology identifier check 0	`[["30", "4"]]`	`{"error": "not-gs1"}`	Failed

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