[format descriptor] heur

RRRS, R3RS: express heuristically using the minimum number of digits required to get an expression that when coerced back to a number produces the original machine representation. Exact numbers are expressed as (int) or (rat). Inexact numbers are expressed as (flo h) or (sci h) depending on their range. Complex numbers are expressed in (rect). This is the normal default of the system printer.

See also int, rat, flo, sci, rect and number->string.