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Diffstat (limited to 'include/ruby/internal/arithmetic/char.h')
| -rw-r--r-- | include/ruby/internal/arithmetic/char.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/include/ruby/internal/arithmetic/char.h b/include/ruby/internal/arithmetic/char.h new file mode 100644 index 0000000000..920fdc0c9d --- /dev/null +++ b/include/ruby/internal/arithmetic/char.h @@ -0,0 +1,81 @@ +#ifndef RBIMPL_ARITHMETIC_CHAR_H /*-*-C++-*-vi:se ft=cpp:*/ +#define RBIMPL_ARITHMETIC_CHAR_H +/** + * @file + * @author Ruby developers <ruby-core@ruby-lang.org> + * @copyright This file is a part of the programming language Ruby. + * Permission is hereby granted, to either redistribute and/or + * modify this file, provided that the conditions mentioned in the + * file COPYING are met. Consult the file for details. + * @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are + * implementation details. Don't take them as canon. They could + * rapidly appear then vanish. The name (path) of this header file + * is also an implementation detail. Do not expect it to persist + * at the place it is now. Developers are free to move it anywhere + * anytime at will. + * @note To ruby-core: remember that this header can be possibly + * recursively included from extension libraries written in C++. + * Do not expect for instance `__VA_ARGS__` is always available. + * We assume C99 for ruby itself but we don't assume languages of + * extension libraries. They could be written in C++98. + * @brief Arithmetic conversion between C's `char` and Ruby's. + */ +#include "ruby/internal/arithmetic/int.h" /* NUM2INT is here, but */ +#include "ruby/internal/arithmetic/long.h" /* INT2FIX is here.*/ +#include "ruby/internal/attr/artificial.h" +#include "ruby/internal/attr/const.h" +#include "ruby/internal/attr/constexpr.h" +#include "ruby/internal/cast.h" +#include "ruby/internal/core/rstring.h" +#include "ruby/internal/value_type.h" + +#define RB_NUM2CHR rb_num2char_inline /**< @alias{rb_num2char_inline} */ +#define NUM2CHR RB_NUM2CHR /**< @old{RB_NUM2CHR} */ +#define CHR2FIX RB_CHR2FIX /**< @old{RB_CHR2FIX} */ + +/** @cond INTERNAL_MACRO */ +#define RB_CHR2FIX RB_CHR2FIX +/** @endcond */ + +RBIMPL_ATTR_CONST_UNLESS_DEBUG() +RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Converts a C's `unsigned char` into an instance of ::rb_cInteger. + * + * @param[in] c Arbitrary `unsigned char` value. + * @return An instance of ::rb_cInteger. + * + * @internal + * + * Nobody explicitly states this but in Ruby, a char means an unsigned integer + * value of range 0..255. This is a general principle. AFAIK there is no + * single line of code where char is signed. + */ +static inline VALUE +RB_CHR2FIX(unsigned char c) +{ + return RB_INT2FIX(c); +} + +/** + * Converts an instance of ::rb_cNumeric into C's `char`. At the same time it + * accepts a String of more than one character, and returns its first byte. In + * the early days there was a Ruby level "character" literal `?c`, which + * roughly worked this way. + * + * @param[in] x Either a string or a numeric. + * @exception rb_eTypeError `x` is not a numeric. + * @exception rb_eRangeError `x` is out of range of `unsigned int`. + * @return The passed value converted into C's `char`. + */ +static inline char +rb_num2char_inline(VALUE x) +{ + if (RB_TYPE_P(x, RUBY_T_STRING) && (RSTRING_LEN(x)>=1)) + return RSTRING_PTR(x)[0]; + else + return RBIMPL_CAST((char)RB_NUM2INT(x)); +} + +#endif /* RBIMPL_ARITHMETIC_CHAR_H */ |