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## Arbitrary precision integers.
## * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt
when not defined(js):
{.fatal: "Module jsbigints is designed to be used with the JavaScript backend.".}
when defined(nimPreviewSlimSystem):
import std/assertions
type JsBigIntImpl {.importjs: "bigint".} = int # https://github.com/nim-lang/Nim/pull/16606
type JsBigInt* = distinct JsBigIntImpl ## Arbitrary precision integer for JavaScript target.
func big*(integer: SomeInteger): JsBigInt {.importjs: "BigInt(#)".} =
## Constructor for `JsBigInt`.
runnableExamples:
doAssert big(1234567890) == big"1234567890"
doAssert 0b1111100111.big == 0o1747.big and 0o1747.big == 999.big
when nimvm: doAssert false, "JsBigInt can not be used at compile-time nor static context" else: discard
func `'big`*(num: cstring): JsBigInt {.importjs: "BigInt(#)".} =
## Constructor for `JsBigInt`.
runnableExamples:
doAssert -1'big == 1'big - 2'big
# supports decimal, binary, octal, hex:
doAssert -12'big == big"-12"
doAssert 12'big == 12.big
doAssert 0b101'big == 0b101.big
doAssert 0o701'big == 0o701.big
doAssert 0xdeadbeaf'big == 0xdeadbeaf.big
doAssert 0xffffffffffffffff'big == (1'big shl 64'big) - 1'big
doAssert not compiles(static(12'big))
when nimvm: doAssert false, "JsBigInt can not be used at compile-time nor static context" else: discard
func big*(integer: cstring): JsBigInt {.importjs: "BigInt(#)".} =
## Alias for `'big`
when nimvm: doAssert false, "JsBigInt can not be used at compile-time nor static context" else: discard
func toCstring*(this: JsBigInt; radix: 2..36): cstring {.importjs: "#.toString(#)".} =
## Converts from `JsBigInt` to `cstring` representation.
## * `radix` Base to use for representing numeric values.
## https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt/toString
runnableExamples:
doAssert big"2147483647".toCstring(2) == "1111111111111111111111111111111".cstring
func toCstring*(this: JsBigInt): cstring {.importjs: "#.toString()".}
## Converts from `JsBigInt` to `cstring` representation.
## https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt/toString
func `$`*(this: JsBigInt): string =
## Returns a `string` representation of `JsBigInt`.
runnableExamples: doAssert $big"1024" == "1024n"
$toCstring(this) & 'n'
func wrapToInt*(this: JsBigInt; bits: Natural): JsBigInt {.importjs:
"(() => { const i = #, b = #; return BigInt.asIntN(b, i) })()".} =
## Wraps `this` to a signed `JsBigInt` of `bits` bits in `-2 ^ (bits - 1)` .. `2 ^ (bits - 1) - 1`.
## https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt/asIntN
runnableExamples:
doAssert (big("3") + big("2") ** big("66")).wrapToInt(13) == big("3")
func wrapToUint*(this: JsBigInt; bits: Natural): JsBigInt {.importjs:
"(() => { const i = #, b = #; return BigInt.asUintN(b, i) })()".} =
## Wraps `this` to an unsigned `JsBigInt` of `bits` bits in 0 .. `2 ^ bits - 1`.
## https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt/asUintN
runnableExamples:
doAssert (big("3") + big("2") ** big("66")).wrapToUint(66) == big("3")
func toNumber*(this: JsBigInt): BiggestInt {.importjs: "Number(#)".} =
## Does not do any bounds check and may or may not return an inexact representation.
runnableExamples:
doAssert toNumber(big"2147483647") == 2147483647.BiggestInt
func `+`*(x, y: JsBigInt): JsBigInt {.importjs: "(# $1 #)".} =
runnableExamples:
doAssert (big"9" + big"1") == big"10"
func `-`*(x, y: JsBigInt): JsBigInt {.importjs: "(# $1 #)".} =
runnableExamples:
doAssert (big"9" - big"1") == big"8"
func `*`*(x, y: JsBigInt): JsBigInt {.importjs: "(# $1 #)".} =
runnableExamples:
doAssert (big"42" * big"9") == big"378"
func `div`*(x, y: JsBigInt): JsBigInt {.importjs: "(# / #)".} =
## Same as `div` but for `JsBigInt`(uses JavaScript `BigInt() / BigInt()`).
runnableExamples:
doAssert big"13" div big"3" == big"4"
doAssert big"-13" div big"3" == big"-4"
doAssert big"13" div big"-3" == big"-4"
doAssert big"-13" div big"-3" == big"4"
func `mod`*(x, y: JsBigInt): JsBigInt {.importjs: "(# % #)".} =
## Same as `mod` but for `JsBigInt` (uses JavaScript `BigInt() % BigInt()`).
runnableExamples:
doAssert big"13" mod big"3" == big"1"
doAssert big"-13" mod big"3" == big"-1"
doAssert big"13" mod big"-3" == big"1"
doAssert big"-13" mod big"-3" == big"-1"
func `<`*(x, y: JsBigInt): bool {.importjs: "(# $1 #)".} =
runnableExamples:
doAssert big"2" < big"9"
func `<=`*(x, y: JsBigInt): bool {.importjs: "(# $1 #)".} =
runnableExamples:
doAssert big"1" <= big"5"
func `==`*(x, y: JsBigInt): bool {.importjs: "(# == #)".} =
runnableExamples:
doAssert big"42" == big"42"
func `**`*(x, y: JsBigInt): JsBigInt {.importjs: "((#) $1 #)".} =
# (#) needed, refs https://github.com/nim-lang/Nim/pull/16409#issuecomment-760550812
runnableExamples:
doAssert big"2" ** big"64" == big"18446744073709551616"
doAssert big"-2" ** big"3" == big"-8"
doAssert -big"2" ** big"2" == big"4" # parsed as: (-2n) ** 2n
doAssert big"0" ** big"0" == big"1" # edge case
var ok = false
try: discard big"2" ** big"-1" # raises foreign `RangeError`
except: ok = true
doAssert ok
# pending https://github.com/nim-lang/Nim/pull/15940, simplify to:
# doAssertRaises: discard big"2" ** big"-1" # raises foreign `RangeError`
func `and`*(x, y: JsBigInt): JsBigInt {.importjs: "(# & #)".} =
runnableExamples:
doAssert (big"555" and big"2") == big"2"
func `or`*(x, y: JsBigInt): JsBigInt {.importjs: "(# | #)".} =
runnableExamples:
doAssert (big"555" or big"2") == big"555"
func `xor`*(x, y: JsBigInt): JsBigInt {.importjs: "(# ^ #)".} =
runnableExamples:
doAssert (big"555" xor big"2") == big"553"
func `shl`*(a, b: JsBigInt): JsBigInt {.importjs: "(# << #)".} =
runnableExamples:
doAssert (big"999" shl big"2") == big"3996"
func `shr`*(a, b: JsBigInt): JsBigInt {.importjs: "(# >> #)".} =
runnableExamples:
doAssert (big"999" shr big"2") == big"249"
func `-`*(this: JsBigInt): JsBigInt {.importjs: "($1#)".} =
runnableExamples:
doAssert -(big"10101010101") == big"-10101010101"
func inc*(this: var JsBigInt) {.importjs: "(++[#][0][0])".} =
runnableExamples:
var big1: JsBigInt = big"1"
inc big1
doAssert big1 == big"2"
func dec*(this: var JsBigInt) {.importjs: "(--[#][0][0])".} =
runnableExamples:
var big1: JsBigInt = big"2"
dec big1
doAssert big1 == big"1"
func inc*(this: var JsBigInt; amount: JsBigInt) {.importjs: "([#][0][0] += #)".} =
runnableExamples:
var big1: JsBigInt = big"1"
inc big1, big"2"
doAssert big1 == big"3"
func dec*(this: var JsBigInt; amount: JsBigInt) {.importjs: "([#][0][0] -= #)".} =
runnableExamples:
var big1: JsBigInt = big"1"
dec big1, big"2"
doAssert big1 == big"-1"
func `+=`*(x: var JsBigInt; y: JsBigInt) {.importjs: "([#][0][0] $1 #)".} =
runnableExamples:
var big1: JsBigInt = big"1"
big1 += big"2"
doAssert big1 == big"3"
func `-=`*(x: var JsBigInt; y: JsBigInt) {.importjs: "([#][0][0] $1 #)".} =
runnableExamples:
var big1: JsBigInt = big"1"
big1 -= big"2"
doAssert big1 == big"-1"
func `*=`*(x: var JsBigInt; y: JsBigInt) {.importjs: "([#][0][0] $1 #)".} =
runnableExamples:
var big1: JsBigInt = big"2"
big1 *= big"4"
doAssert big1 == big"8"
func `/=`*(x: var JsBigInt; y: JsBigInt) {.importjs: "([#][0][0] $1 #)".} =
## Same as `x = x div y`.
runnableExamples:
var big1: JsBigInt = big"11"
big1 /= big"2"
doAssert big1 == big"5"
proc `+`*(_: JsBigInt): JsBigInt {.error:
"See https://github.com/tc39/proposal-bigint/blob/master/ADVANCED.md#dont-break-asmjs".} # Can not be used by design
## **Do NOT use.** https://github.com/tc39/proposal-bigint/blob/master/ADVANCED.md#dont-break-asmjs
proc low*(_: typedesc[JsBigInt]): JsBigInt {.error:
"Arbitrary precision integers do not have a known low.".} ## **Do NOT use.**
proc high*(_: typedesc[JsBigInt]): JsBigInt {.error:
"Arbitrary precision integers do not have a known high.".} ## **Do NOT use.**
runnableExamples:
block:
let big1: JsBigInt = big"2147483647"
let big2: JsBigInt = big"666"
doAssert JsBigInt isnot int
doAssert big1 != big2
doAssert big1 > big2
doAssert big1 >= big2
doAssert big2 < big1
doAssert big2 <= big1
doAssert not(big1 == big2)
let z = JsBigInt.default
doAssert $z == "0n"
block:
var a: seq[JsBigInt]
a.setLen 2
doAssert a == @[big"0", big"0"]
doAssert a[^1] == big"0"
var b: JsBigInt
doAssert b == big"0"
doAssert b == JsBigInt.default
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