Weidner base52 alphabet: exact digit round trip and strict order

What this target establishes

Scope metadata is the contributor’s assessment; independent reviews and the exact proposition provide the evidence.

Obligations

codec round trip

Cost metric

none

Model

One ASCII digit represented by its natural-number code; exact integer arithmetic.

Assumptions

Digit inputs are natural numbers strictly below 52.

Implementation correspondence

algorithm model

Limitations

No whole-string parser, Unicode normalization, variable-length prefix freedom, encoded-size optimality or JavaScript numeric refinement is claimed.