FA-79615 / Barcode symbology encoding / Member archive

A separator after a fixed-length field is reported as an unknown AI · case 05

Labels from printers that add FNC1 after every field fail to parse.

Member previewVariant 5 · 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: redundant GS skipping 0	`{"at": 8, "error": "unknown-ai"}`	`[["21", "9A9"], ["17", "625625"]]`	Failed

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

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