FA-79474 / Barcode symbology encoding / Member archive

Full ASCII Code 39 leaves $ % + / unescaped · case 04

A price such as "$5" decodes in full ASCII readers as a control character.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

Encode text for Code 39 with a wide:narrow ratio of 2 or 3. Standard mode accepts only the 43 characters 0-9 A-Z - . space $ / + %. Full ASCII mode maps lowercase to "+" plus the capital, controls 1..26 to "$" plus A..Z, NUL to %U, 27..31 to %A..%E, DEL to %T, and punctuation (including the four standard shift characters $ % + /) to its two-character escape. Every symbol character, including the start/stop "*", has 6 narrow and 3 wide elements, and one narrow gap separates adjacent characters. Return the framed data and the total width in narrow modules.

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: escaping the shift characters 0	`{"data": "/J+A++B50%", "modules": 155}`	`{"data": "/J+A/K+B50/E", "modules": 181}`	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.