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Developer Guide

Rounding

RoundingMode accepts the classic BigDecimal mode names:

Mode	Behavior
UP	Away from zero
DOWN	Toward zero (truncation)
CEILING	Toward +∞
FLOOR	Toward −∞
HALF_UP	Nearest, ties away from zero — default, matches PG round()
HALF_DOWN	Nearest, ties toward zero
HALF_EVEN	Nearest, ties to even digit (banker's rounding)

Where modes apply

Code
round("12.345", 2);                       // 12.35 (HALF_UP default)
round("12.345", 2, "HALF_EVEN");          // 12.34 (banker's)
rescale("9.876", 1);                      // 9.9
setScale("9.876", 3, "DOWN");             // 9.876 — pads or truncates to exactly 3
div(a, b, { scale: 6, rounding: "FLOOR" });// floor division at scale 6

Related transforms

• trunc(d) — integer part (toward zero)
• floor(d) / ceil(d) — integer toward −∞ / +∞
• normalize(d) — strip trailing zeros (12.3400 → 12.34; v/scale minimized). Note: normalize changes scale, so strictEq on a normalized and un-normalized equal value is false — use eq for value comparison.