81 lines
2.9 KiB
C++
81 lines
2.9 KiB
C++
#ifndef RBIMPL_RBIGNUM_H /*-*-C++-*-vi:se ft=cpp:*/
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#define RBIMPL_RBIGNUM_H
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/**
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* @file
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* @author Ruby developers <ruby-core@ruby-lang.org>
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* @copyright This file is a part of the programming language Ruby.
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* Permission is hereby granted, to either redistribute and/or
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* modify this file, provided that the conditions mentioned in the
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* file COPYING are met. Consult the file for details.
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* @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are
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* implementation details. Don't take them as canon. They could
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* rapidly appear then vanish. The name (path) of this header file
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* is also an implementation detail. Do not expect it to persist
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* at the place it is now. Developers are free to move it anywhere
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* anytime at will.
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* @note To ruby-core: remember that this header can be possibly
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* recursively included from extension libraries written in C++.
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* Do not expect for instance `__VA_ARGS__` is always available.
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* We assume C99 for ruby itself but we don't assume languages of
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* extension libraries. They could be written in C++98.
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* @brief Routines to manipulate struct RBignum.
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* @note The struct RBignum itself is opaque.
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*/
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#include "ruby/internal/dllexport.h"
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#include "ruby/internal/value.h"
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#include "ruby/internal/value_type.h"
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#include "ruby/internal/stdbool.h"
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#define RBIGNUM_SIGN rb_big_sign /**< @alias{rb_big_sign} */
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/** @cond INTERNAL_MACRO */
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#define RBIGNUM_POSITIVE_P RBIGNUM_POSITIVE_P
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#define RBIGNUM_NEGATIVE_P RBIGNUM_NEGATIVE_P
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/** @endcond */
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RBIMPL_SYMBOL_EXPORT_BEGIN()
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/**
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* The "sign" of a bignum.
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*
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* @param[in] num An object of RBignum.
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* @retval 1 It is greater than or equal to zero.
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* @retval 0 It is less than zero.
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*
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* @internal
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*
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* Implementation wise, unlike fixnums (which are 2's complement), bignums are
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* signed magnitude system. Theoretically it could be possible to have
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* negative zero instances. But in reality there is no way to create such
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* thing. Nobody ever needed that kind of insanity.
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*/
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int rb_big_sign(VALUE num);
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RBIMPL_SYMBOL_EXPORT_END()
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/**
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* Checks if the bignum is positive.
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* @param[in] b An object of RBignum.
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* @retval false `b` is less than zero.
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* @retval true Otherwise.
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*/
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static inline bool
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RBIGNUM_POSITIVE_P(VALUE b)
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{
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RBIMPL_ASSERT_TYPE(b, RUBY_T_BIGNUM);
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return RBIGNUM_SIGN(b);
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}
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/**
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* Checks if the bignum is negative.
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* @param[in] b An object of RBignum.
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* @retval true `b` is less than zero.
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* @retval false Otherwise.
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*/
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static inline bool
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RBIGNUM_NEGATIVE_P(VALUE b)
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{
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RBIMPL_ASSERT_TYPE(b, RUBY_T_BIGNUM);
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return ! RBIGNUM_POSITIVE_P(b);
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}
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#endif /* RBIMPL_RBIGNUM_H */
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