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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /js/public/BigInt.h | |
parent | Initial commit. (diff) | |
download | thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | js/public/BigInt.h | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/js/public/BigInt.h b/js/public/BigInt.h new file mode 100644 index 0000000000..94f4aab5c4 --- /dev/null +++ b/js/public/BigInt.h @@ -0,0 +1,229 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* BigInt. */ + +#ifndef js_BigInt_h +#define js_BigInt_h + +#include "mozilla/Span.h" // mozilla::Span + +#include <limits> // std::numeric_limits +#include <stdint.h> // int64_t, uint64_t +#include <type_traits> // std::enable_if_t, std::{true,false}_type, std::is_{integral,signed,unsigned}_v + +#include "jstypes.h" // JS_PUBLIC_API +#include "js/TypeDecls.h" + +namespace mozilla { +template <typename T> +class Range; +} + +namespace JS { + +class JS_PUBLIC_API BigInt; + +namespace detail { + +using Int64Limits = std::numeric_limits<int64_t>; +using Uint64Limits = std::numeric_limits<uint64_t>; + +extern JS_PUBLIC_API BigInt* BigIntFromInt64(JSContext* cx, int64_t num); +extern JS_PUBLIC_API BigInt* BigIntFromUint64(JSContext* cx, uint64_t num); +extern JS_PUBLIC_API BigInt* BigIntFromBool(JSContext* cx, bool b); + +template <typename T, typename = void> +struct NumberToBigIntConverter; + +template <typename SignedIntT> +struct NumberToBigIntConverter< + SignedIntT, + std::enable_if_t< + std::is_integral_v<SignedIntT> && std::is_signed_v<SignedIntT> && + Int64Limits::min() <= std::numeric_limits<SignedIntT>::min() && + std::numeric_limits<SignedIntT>::max() <= Int64Limits::max()>> { + static BigInt* convert(JSContext* cx, SignedIntT num) { + return BigIntFromInt64(cx, num); + } +}; + +template <typename UnsignedIntT> +struct NumberToBigIntConverter< + UnsignedIntT, + std::enable_if_t< + std::is_integral_v<UnsignedIntT> && std::is_unsigned_v<UnsignedIntT> && + std::numeric_limits<UnsignedIntT>::max() <= Uint64Limits::max()>> { + static BigInt* convert(JSContext* cx, UnsignedIntT num) { + return BigIntFromUint64(cx, num); + } +}; + +template <> +struct NumberToBigIntConverter<bool> { + static BigInt* convert(JSContext* cx, bool b) { + return BigIntFromBool(cx, b); + } +}; + +extern JS_PUBLIC_API bool BigIntIsInt64(BigInt* bi, int64_t* result); +extern JS_PUBLIC_API bool BigIntIsUint64(BigInt* bi, uint64_t* result); + +template <typename T, typename = void> +struct BigIntToNumberChecker; + +template <typename SignedIntT> +struct BigIntToNumberChecker< + SignedIntT, + std::enable_if_t< + std::is_integral_v<SignedIntT> && std::is_signed_v<SignedIntT> && + Int64Limits::min() <= std::numeric_limits<SignedIntT>::min() && + std::numeric_limits<SignedIntT>::max() <= Int64Limits::max()>> { + using TypeLimits = std::numeric_limits<SignedIntT>; + + static bool fits(BigInt* bi, SignedIntT* result) { + int64_t innerResult; + if (!BigIntIsInt64(bi, &innerResult)) { + return false; + } + if (TypeLimits::min() <= innerResult && innerResult <= TypeLimits::max()) { + *result = SignedIntT(innerResult); + return true; + } + return false; + } +}; + +template <typename UnsignedIntT> +struct BigIntToNumberChecker< + UnsignedIntT, + std::enable_if_t< + std::is_integral_v<UnsignedIntT> && std::is_unsigned_v<UnsignedIntT> && + std::numeric_limits<UnsignedIntT>::max() <= Uint64Limits::max()>> { + static bool fits(BigInt* bi, UnsignedIntT* result) { + uint64_t innerResult; + if (!BigIntIsUint64(bi, &innerResult)) { + return false; + } + if (innerResult <= std::numeric_limits<UnsignedIntT>::max()) { + *result = UnsignedIntT(innerResult); + return true; + } + return false; + } +}; + +} // namespace detail + +/** + * Create a BigInt from an integer value. All integral types not larger than 64 + * bits in size are supported. + */ +template <typename NumericT> +static inline BigInt* NumberToBigInt(JSContext* cx, NumericT val) { + return detail::NumberToBigIntConverter<NumericT>::convert(cx, val); +} + +/** + * Create a BigInt from a floating-point value. If the number isn't integral + * (that is, if it's NaN, an infinity, or contains a fractional component), + * this function returns null and throws an exception. + * + * Passing -0.0 will produce the bigint 0n. + */ +extern JS_PUBLIC_API BigInt* NumberToBigInt(JSContext* cx, double num); + +/** + * Create a BigInt by parsing a string using the ECMAScript StringToBigInt + * algorithm (https://tc39.es/ecma262/#sec-stringtobigint). Latin1 and two-byte + * character ranges are supported. It may be convenient to use + * JS::ConstLatin1Chars or JS::ConstTwoByteChars. + * + * (StringToBigInt performs parsing similar to that performed by the |Number| + * global function when passed a string, but it doesn't allow infinities, + * decimal points, or exponential notation, and neither algorithm allows numeric + * separators or an 'n' suffix character. This fast-and-loose description is + * offered purely as a convenience to the reader: see the specification + * algorithm for exact behavior.) + * + * If parsing fails, this function returns null and throws an exception. + */ +extern JS_PUBLIC_API BigInt* StringToBigInt( + JSContext* cx, mozilla::Range<const Latin1Char> chars); + +extern JS_PUBLIC_API BigInt* StringToBigInt( + JSContext* cx, mozilla::Range<const char16_t> chars); + +/** + * Create a BigInt by parsing a string consisting of an optional sign character + * followed by one or more alphanumeric ASCII digits in the provided radix. + * + * If the radix is not in the range [2, 36], or the string fails to parse, this + * function returns null and throws an exception. + */ +extern JS_PUBLIC_API BigInt* SimpleStringToBigInt( + JSContext* cx, mozilla::Span<const char> chars, uint8_t radix); + +/** + * Convert a JS::Value to a BigInt using the ECMAScript ToBigInt algorithm + * (https://tc39.es/ecma262/#sec-tobigint). + * + * (Note in particular that this will throw if passed a value whose type is + * 'number'. To convert a number to a BigInt, use one of the overloads of + * JS::NumberToBigInt().) + */ +extern JS_PUBLIC_API BigInt* ToBigInt(JSContext* cx, Handle<Value> val); + +/** + * Convert the given BigInt, modulo 2**64, to a signed 64-bit integer. + */ +extern JS_PUBLIC_API int64_t ToBigInt64(BigInt* bi); + +/** + * Convert the given BigInt, modulo 2**64, to an unsigned 64-bit integer. + */ +extern JS_PUBLIC_API uint64_t ToBigUint64(BigInt* bi); + +/** + * Convert the given BigInt to a Number value as if calling the Number + * constructor on it + * (https://tc39.es/ecma262/#sec-number-constructor-number-value). The value + * may be rounded if it doesn't fit without loss of precision. + */ +extern JS_PUBLIC_API double BigIntToNumber(BigInt* bi); + +/** + * Return true if the given BigInt is negative. + */ +extern JS_PUBLIC_API bool BigIntIsNegative(BigInt* bi); + +/** + * Return true if the given BigInt fits inside the given NumericT type without + * loss of precision, and store the value in the out parameter. Otherwise return + * false and leave the value of the out parameter unspecified. + */ +template <typename NumericT> +static inline bool BigIntFits(BigInt* bi, NumericT* out) { + return detail::BigIntToNumberChecker<NumericT>::fits(bi, out); +} + +/** + * Same as BigIntFits(), but checks if the value fits inside a JS Number value. + */ +extern JS_PUBLIC_API bool BigIntFitsNumber(BigInt* bi, double* out); + +/** + * Convert the given BigInt to a String value as if toString() were called on + * it. + * + * If the radix is not in the range [2, 36], then this function returns null and + * throws an exception. + */ +extern JS_PUBLIC_API JSString* BigIntToString(JSContext* cx, Handle<BigInt*> bi, + uint8_t radix); + +} // namespace JS + +#endif /* js_BigInt_h */ |