< Rebol Programming
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]
]
]
]
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