Rebol Programming/round

USAGE: ROUND n /even /down /half-down /floor /ceiling /half-ceiling /to scale DESCRIPTION: Returns the nearest integer. Halves round up (away from zero) by default. ROUND is a function value. ARGUMENTS n -- The value to round (Type: number money time) REFINEMENTS /even -- Halves round toward even results /down -- Round toward zero, ignoring discarded digits. (truncate) /half-down -- Halves round toward zero /floor -- Round in negative direction /ceiling -- Round in positive direction /half-ceiling -- Halves round in positive direction /to -- Return the nearest multiple of the scale parameter scale -- Must be a non-zero value (Type: number money time) (SPECIAL ATTRIBUTES) catch SOURCE CODE round: func [ {Returns the nearest integer. Halves round up (away from zero) by default.} [catch] n [number! money! time!] "The value to round" /even "Halves round toward even results" /down {Round toward zero, ignoring discarded digits. (truncate)} /half-down "Halves round toward zero" /floor "Round in negative direction" /ceiling "Round in positive direction" /half-ceiling "Halves round in positive direction" /to "Return the nearest multiple of the scale parameter" scale [number! money! time!] "Must be a non-zero value" /local m ][ throw-on-error [ scale: abs any [scale 1] any [number? n scale: make n scale] make scale either any [even half-ceiling] [ m: 0.5 * scale + n any [ all [ m = m: m - mod m scale even positive? m - n m - mod m scale + scale ] m ] ] [ any [ floor ceiling (ceiling: (found? half-down) xor negative? n down) n: add n scale * pick [-0.5 0.5] ceiling ] either ceiling [n + mod negate n scale] [n - mod n scale] ] ] ]