You should check with SRFI 166 first and, if still relevant, ask the question there.

A number of issues with SRFI 159 have already been fixed there.

Am So., 16. Feb. 2020 um 05:58 Uhr schrieb Duy Nguyen <xxxxxx@gmail.com>:
The "numeric" formatter states

"These parameters may seem unwieldy, but they can also take their
defaults from state variables, described below. "

but only precision, radix and decimal-step are described in the
"standard state variables" section. The three mentioned in subject
line are used by the reference implementation but not described.

Are these undefined on purpose or just an oversight?
--
Duy


--
Prof. Dr. Marc Nieper-Wißkirchen
 
Universität Augsburg
Institut für Mathematik
Universitätsstraße 14
86159 Augsburg
 
Tel: 0821/598-2146
Fax: 0821/598-2090
 
E-Mail: xxxxxx@math.uni-augsburg.de
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