pub fn read_unit() -> Result<Option<(i64, i64)>>Expand description
Read a unit, returning the exact TeX (num, den) conversion fraction (see
convert_unit_ratio / numeric_ops::fixpoint_unit). Internal/coerced units
(\wd0, \dimen, glue) yield (value_sp, 65536) — the floor(fix·v/65536)
path of tex.web §8983, exact in integer arithmetic.