The picture parses into affixes, number part, and the negative
subpattern: literal prefixes and suffixes pass through, the negative
subpattern's affixes apply (with the default minus when it has no
distinguishing ones), per-mille and percent multiply and stay literal,
the grouping size derives from the pattern's last grouping separator,
colliding decimal/grouping separators read as grouping, and U+00A4
renders as the en-US currency symbol. Digit extraction now uses one
scaled rounding and integer arithmetic, eliminating per-digit float
drift. Xalan numberformat 30 -> 1; baseline 475 -> 446.