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-rw-r--r--rational.c2830
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diff --git a/rational.c b/rational.c
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+++ b/rational.c
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+/*
+ rational.c: Coded by Tadayoshi Funaba 2008-2012
+
+ This implementation is based on Keiju Ishitsuka's Rational library
+ which is written in ruby.
+*/
+
+#include "ruby/internal/config.h"
+
+#include <ctype.h>
+#include <float.h>
+#include <math.h>
+
+#ifdef HAVE_IEEEFP_H
+#include <ieeefp.h>
+#endif
+
+#if !defined(USE_GMP)
+#if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H)
+# define USE_GMP 1
+#else
+# define USE_GMP 0
+#endif
+#endif
+
+#include "id.h"
+#include "internal.h"
+#include "internal/array.h"
+#include "internal/complex.h"
+#include "internal/gc.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/rational.h"
+#include "ruby_assert.h"
+
+#if USE_GMP
+RBIMPL_WARNING_PUSH()
+# ifdef _MSC_VER
+RBIMPL_WARNING_IGNORED(4146) /* for mpn_neg() */
+# endif
+# include <gmp.h>
+RBIMPL_WARNING_POP()
+#endif
+
+#define ZERO INT2FIX(0)
+#define ONE INT2FIX(1)
+#define TWO INT2FIX(2)
+
+#define GMP_GCD_DIGITS 1
+
+#define INT_ZERO_P(x) (FIXNUM_P(x) ? FIXNUM_ZERO_P(x) : rb_bigzero_p(x))
+
+VALUE rb_cRational;
+
+static ID id_abs, id_integer_p,
+ id_i_num, id_i_den;
+
+#define id_idiv idDiv
+#define id_to_i idTo_i
+
+#define f_inspect rb_inspect
+#define f_to_s rb_obj_as_string
+
+static VALUE nurat_to_f(VALUE self);
+static VALUE float_to_r(VALUE self);
+
+inline static VALUE
+f_add(VALUE x, VALUE y)
+{
+ if (FIXNUM_ZERO_P(y))
+ return x;
+ if (FIXNUM_ZERO_P(x))
+ return y;
+ if (RB_INTEGER_TYPE_P(x))
+ return rb_int_plus(x, y);
+ return rb_funcall(x, '+', 1, y);
+}
+
+inline static VALUE
+f_div(VALUE x, VALUE y)
+{
+ if (y == ONE)
+ return x;
+ if (RB_INTEGER_TYPE_P(x))
+ return rb_int_div(x, y);
+ return rb_funcall(x, '/', 1, y);
+}
+
+inline static int
+f_lt_p(VALUE x, VALUE y)
+{
+ if (FIXNUM_P(x) && FIXNUM_P(y))
+ return (SIGNED_VALUE)x < (SIGNED_VALUE)y;
+ if (RB_INTEGER_TYPE_P(x)) {
+ VALUE r = rb_int_cmp(x, y);
+ if (!NIL_P(r)) return rb_int_negative_p(r);
+ }
+ return RTEST(rb_funcall(x, '<', 1, y));
+}
+
+#ifndef NDEBUG
+/* f_mod is used only in f_gcd defined when NDEBUG is not defined */
+inline static VALUE
+f_mod(VALUE x, VALUE y)
+{
+ if (RB_INTEGER_TYPE_P(x))
+ return rb_int_modulo(x, y);
+ return rb_funcall(x, '%', 1, y);
+}
+#endif
+
+inline static VALUE
+f_mul(VALUE x, VALUE y)
+{
+ if (FIXNUM_ZERO_P(y) && RB_INTEGER_TYPE_P(x))
+ return ZERO;
+ if (y == ONE) return x;
+ if (FIXNUM_ZERO_P(x) && RB_INTEGER_TYPE_P(y))
+ return ZERO;
+ if (x == ONE) return y;
+ else if (RB_INTEGER_TYPE_P(x))
+ return rb_int_mul(x, y);
+ return rb_funcall(x, '*', 1, y);
+}
+
+inline static VALUE
+f_sub(VALUE x, VALUE y)
+{
+ if (FIXNUM_P(y) && FIXNUM_ZERO_P(y))
+ return x;
+ return rb_funcall(x, '-', 1, y);
+}
+
+inline static VALUE
+f_abs(VALUE x)
+{
+ if (RB_INTEGER_TYPE_P(x))
+ return rb_int_abs(x);
+ return rb_funcall(x, id_abs, 0);
+}
+
+
+inline static int
+f_integer_p(VALUE x)
+{
+ return RB_INTEGER_TYPE_P(x);
+}
+
+inline static VALUE
+f_to_i(VALUE x)
+{
+ if (RB_TYPE_P(x, T_STRING))
+ return rb_str_to_inum(x, 10, 0);
+ return rb_funcall(x, id_to_i, 0);
+}
+
+inline static int
+f_eqeq_p(VALUE x, VALUE y)
+{
+ if (FIXNUM_P(x) && FIXNUM_P(y))
+ return x == y;
+ if (RB_INTEGER_TYPE_P(x))
+ return RTEST(rb_int_equal(x, y));
+ return (int)rb_equal(x, y);
+}
+
+inline static VALUE
+f_idiv(VALUE x, VALUE y)
+{
+ if (RB_INTEGER_TYPE_P(x))
+ return rb_int_idiv(x, y);
+ return rb_funcall(x, id_idiv, 1, y);
+}
+
+#define f_expt10(x) rb_int_pow(INT2FIX(10), x)
+
+inline static int
+f_zero_p(VALUE x)
+{
+ if (RB_INTEGER_TYPE_P(x)) {
+ return FIXNUM_ZERO_P(x);
+ }
+ else if (RB_TYPE_P(x, T_RATIONAL)) {
+ VALUE num = RRATIONAL(x)->num;
+
+ return FIXNUM_ZERO_P(num);
+ }
+ return (int)rb_equal(x, ZERO);
+}
+
+#define f_nonzero_p(x) (!f_zero_p(x))
+
+inline static int
+f_one_p(VALUE x)
+{
+ if (RB_INTEGER_TYPE_P(x)) {
+ return x == LONG2FIX(1);
+ }
+ else if (RB_TYPE_P(x, T_RATIONAL)) {
+ VALUE num = RRATIONAL(x)->num;
+ VALUE den = RRATIONAL(x)->den;
+
+ return num == LONG2FIX(1) && den == LONG2FIX(1);
+ }
+ return (int)rb_equal(x, ONE);
+}
+
+inline static int
+f_minus_one_p(VALUE x)
+{
+ if (RB_INTEGER_TYPE_P(x)) {
+ return x == LONG2FIX(-1);
+ }
+ else if (RB_BIGNUM_TYPE_P(x)) {
+ return Qfalse;
+ }
+ else if (RB_TYPE_P(x, T_RATIONAL)) {
+ VALUE num = RRATIONAL(x)->num;
+ VALUE den = RRATIONAL(x)->den;
+
+ return num == LONG2FIX(-1) && den == LONG2FIX(1);
+ }
+ return (int)rb_equal(x, INT2FIX(-1));
+}
+
+inline static int
+f_kind_of_p(VALUE x, VALUE c)
+{
+ return (int)rb_obj_is_kind_of(x, c);
+}
+
+inline static int
+k_numeric_p(VALUE x)
+{
+ return f_kind_of_p(x, rb_cNumeric);
+}
+
+inline static int
+k_integer_p(VALUE x)
+{
+ return RB_INTEGER_TYPE_P(x);
+}
+
+inline static int
+k_float_p(VALUE x)
+{
+ return RB_FLOAT_TYPE_P(x);
+}
+
+inline static int
+k_rational_p(VALUE x)
+{
+ return RB_TYPE_P(x, T_RATIONAL);
+}
+
+#define k_exact_p(x) (!k_float_p(x))
+#define k_inexact_p(x) k_float_p(x)
+
+#define k_exact_zero_p(x) (k_exact_p(x) && f_zero_p(x))
+#define k_exact_one_p(x) (k_exact_p(x) && f_one_p(x))
+
+#if USE_GMP
+VALUE
+rb_gcd_gmp(VALUE x, VALUE y)
+{
+ const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGIT)*CHAR_BIT;
+ mpz_t mx, my, mz;
+ size_t count;
+ VALUE z;
+ long zn;
+
+ mpz_init(mx);
+ mpz_init(my);
+ mpz_init(mz);
+ mpz_import(mx, BIGNUM_LEN(x), -1, sizeof(BDIGIT), 0, nails, BIGNUM_DIGITS(x));
+ mpz_import(my, BIGNUM_LEN(y), -1, sizeof(BDIGIT), 0, nails, BIGNUM_DIGITS(y));
+
+ mpz_gcd(mz, mx, my);
+
+ mpz_clear(mx);
+ mpz_clear(my);
+
+ zn = (mpz_sizeinbase(mz, 16) + SIZEOF_BDIGIT*2 - 1) / (SIZEOF_BDIGIT*2);
+ z = rb_big_new(zn, 1);
+ mpz_export(BIGNUM_DIGITS(z), &count, -1, sizeof(BDIGIT), 0, nails, mz);
+
+ mpz_clear(mz);
+
+ return rb_big_norm(z);
+}
+#endif
+
+#ifndef NDEBUG
+#define f_gcd f_gcd_orig
+#endif
+
+inline static long
+i_gcd(long x, long y)
+{
+ unsigned long u, v, t;
+ int shift;
+
+ if (x < 0)
+ x = -x;
+ if (y < 0)
+ y = -y;
+
+ if (x == 0)
+ return y;
+ if (y == 0)
+ return x;
+
+ u = (unsigned long)x;
+ v = (unsigned long)y;
+ for (shift = 0; ((u | v) & 1) == 0; ++shift) {
+ u >>= 1;
+ v >>= 1;
+ }
+
+ while ((u & 1) == 0)
+ u >>= 1;
+
+ do {
+ while ((v & 1) == 0)
+ v >>= 1;
+
+ if (u > v) {
+ t = v;
+ v = u;
+ u = t;
+ }
+ v = v - u;
+ } while (v != 0);
+
+ return (long)(u << shift);
+}
+
+inline static VALUE
+f_gcd_normal(VALUE x, VALUE y)
+{
+ VALUE z;
+
+ if (FIXNUM_P(x) && FIXNUM_P(y))
+ return LONG2NUM(i_gcd(FIX2LONG(x), FIX2LONG(y)));
+
+ if (INT_NEGATIVE_P(x))
+ x = rb_int_uminus(x);
+ if (INT_NEGATIVE_P(y))
+ y = rb_int_uminus(y);
+
+ if (INT_ZERO_P(x))
+ return y;
+ if (INT_ZERO_P(y))
+ return x;
+
+ for (;;) {
+ if (FIXNUM_P(x)) {
+ if (FIXNUM_ZERO_P(x))
+ return y;
+ if (FIXNUM_P(y))
+ return LONG2NUM(i_gcd(FIX2LONG(x), FIX2LONG(y)));
+ }
+ z = x;
+ x = rb_int_modulo(y, x);
+ y = z;
+ }
+ /* NOTREACHED */
+}
+
+VALUE
+rb_gcd_normal(VALUE x, VALUE y)
+{
+ return f_gcd_normal(x, y);
+}
+
+inline static VALUE
+f_gcd(VALUE x, VALUE y)
+{
+#if USE_GMP
+ if (RB_BIGNUM_TYPE_P(x) && RB_BIGNUM_TYPE_P(y)) {
+ size_t xn = BIGNUM_LEN(x);
+ size_t yn = BIGNUM_LEN(y);
+ if (GMP_GCD_DIGITS <= xn || GMP_GCD_DIGITS <= yn)
+ return rb_gcd_gmp(x, y);
+ }
+#endif
+ return f_gcd_normal(x, y);
+}
+
+#ifndef NDEBUG
+#undef f_gcd
+
+inline static VALUE
+f_gcd(VALUE x, VALUE y)
+{
+ VALUE r = f_gcd_orig(x, y);
+ if (f_nonzero_p(r)) {
+ RUBY_ASSERT(f_zero_p(f_mod(x, r)));
+ RUBY_ASSERT(f_zero_p(f_mod(y, r)));
+ }
+ return r;
+}
+#endif
+
+inline static VALUE
+f_lcm(VALUE x, VALUE y)
+{
+ if (INT_ZERO_P(x) || INT_ZERO_P(y))
+ return ZERO;
+ return f_abs(f_mul(f_div(x, f_gcd(x, y)), y));
+}
+
+#define get_dat1(x) \
+ struct RRational *dat = RRATIONAL(x)
+
+#define get_dat2(x,y) \
+ struct RRational *adat = RRATIONAL(x), *bdat = RRATIONAL(y)
+
+inline static VALUE
+nurat_s_new_internal(VALUE klass, VALUE num, VALUE den)
+{
+ NEWOBJ_OF(obj, struct RRational, klass, T_RATIONAL | (RGENGC_WB_PROTECTED_RATIONAL ? FL_WB_PROTECTED : 0),
+ sizeof(struct RRational), 0);
+
+ RATIONAL_SET_NUM((VALUE)obj, num);
+ RATIONAL_SET_DEN((VALUE)obj, den);
+ OBJ_FREEZE((VALUE)obj);
+
+ return (VALUE)obj;
+}
+
+static VALUE
+nurat_s_alloc(VALUE klass)
+{
+ return nurat_s_new_internal(klass, ZERO, ONE);
+}
+
+inline static VALUE
+f_rational_new_bang1(VALUE klass, VALUE x)
+{
+ return nurat_s_new_internal(klass, x, ONE);
+}
+
+inline static void
+nurat_int_check(VALUE num)
+{
+ if (!RB_INTEGER_TYPE_P(num)) {
+ if (!k_numeric_p(num) || !f_integer_p(num))
+ rb_raise(rb_eTypeError, "not an integer");
+ }
+}
+
+inline static VALUE
+nurat_int_value(VALUE num)
+{
+ nurat_int_check(num);
+ if (!k_integer_p(num))
+ num = f_to_i(num);
+ return num;
+}
+
+static void
+nurat_canonicalize(VALUE *num, VALUE *den)
+{
+ RUBY_ASSERT(num); RUBY_ASSERT(RB_INTEGER_TYPE_P(*num));
+ RUBY_ASSERT(den); RUBY_ASSERT(RB_INTEGER_TYPE_P(*den));
+ if (INT_NEGATIVE_P(*den)) {
+ *num = rb_int_uminus(*num);
+ *den = rb_int_uminus(*den);
+ }
+ else if (INT_ZERO_P(*den)) {
+ rb_num_zerodiv();
+ }
+}
+
+static void
+nurat_reduce(VALUE *x, VALUE *y)
+{
+ VALUE gcd;
+ if (*x == ONE || *y == ONE) return;
+ gcd = f_gcd(*x, *y);
+ *x = f_idiv(*x, gcd);
+ *y = f_idiv(*y, gcd);
+}
+
+inline static VALUE
+nurat_s_canonicalize_internal(VALUE klass, VALUE num, VALUE den)
+{
+ nurat_canonicalize(&num, &den);
+ nurat_reduce(&num, &den);
+
+ return nurat_s_new_internal(klass, num, den);
+}
+
+inline static VALUE
+nurat_s_canonicalize_internal_no_reduce(VALUE klass, VALUE num, VALUE den)
+{
+ nurat_canonicalize(&num, &den);
+
+ return nurat_s_new_internal(klass, num, den);
+}
+
+inline static VALUE
+f_rational_new2(VALUE klass, VALUE x, VALUE y)
+{
+ RUBY_ASSERT(!k_rational_p(x));
+ RUBY_ASSERT(!k_rational_p(y));
+ return nurat_s_canonicalize_internal(klass, x, y);
+}
+
+inline static VALUE
+f_rational_new_no_reduce2(VALUE klass, VALUE x, VALUE y)
+{
+ RUBY_ASSERT(!k_rational_p(x));
+ RUBY_ASSERT(!k_rational_p(y));
+ return nurat_s_canonicalize_internal_no_reduce(klass, x, y);
+}
+
+static VALUE nurat_convert(VALUE klass, VALUE numv, VALUE denv, int raise);
+static VALUE nurat_s_convert(int argc, VALUE *argv, VALUE klass);
+
+/*
+ * call-seq:
+ * Rational(x, y, exception: true) -> rational or nil
+ * Rational(arg, exception: true) -> rational or nil
+ *
+ * Returns +x/y+ or +arg+ as a Rational.
+ *
+ * Rational(2, 3) #=> (2/3)
+ * Rational(5) #=> (5/1)
+ * Rational(0.5) #=> (1/2)
+ * Rational(0.3) #=> (5404319552844595/18014398509481984)
+ *
+ * Rational("2/3") #=> (2/3)
+ * Rational("0.3") #=> (3/10)
+ *
+ * Rational("10 cents") #=> ArgumentError
+ * Rational(nil) #=> TypeError
+ * Rational(1, nil) #=> TypeError
+ *
+ * Rational("10 cents", exception: false) #=> nil
+ *
+ * Syntax of the string form:
+ *
+ * string form = extra spaces , rational , extra spaces ;
+ * rational = [ sign ] , unsigned rational ;
+ * unsigned rational = numerator | numerator , "/" , denominator ;
+ * numerator = integer part | fractional part | integer part , fractional part ;
+ * denominator = digits ;
+ * integer part = digits ;
+ * fractional part = "." , digits , [ ( "e" | "E" ) , [ sign ] , digits ] ;
+ * sign = "-" | "+" ;
+ * digits = digit , { digit | "_" , digit } ;
+ * digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ;
+ * extra spaces = ? \s* ? ;
+ *
+ * See also String#to_r.
+ */
+static VALUE
+nurat_f_rational(int argc, VALUE *argv, VALUE klass)
+{
+ VALUE a1, a2, opts = Qnil;
+ int raise = TRUE;
+
+ if (rb_scan_args(argc, argv, "11:", &a1, &a2, &opts) == 1) {
+ a2 = Qundef;
+ }
+ if (!NIL_P(opts)) {
+ raise = rb_opts_exception_p(opts, raise);
+ }
+ return nurat_convert(rb_cRational, a1, a2, raise);
+}
+
+/*
+ * call-seq:
+ * rat.numerator -> integer
+ *
+ * Returns the numerator.
+ *
+ * Rational(7).numerator #=> 7
+ * Rational(7, 1).numerator #=> 7
+ * Rational(9, -4).numerator #=> -9
+ * Rational(-2, -10).numerator #=> 1
+ */
+static VALUE
+nurat_numerator(VALUE self)
+{
+ get_dat1(self);
+ return dat->num;
+}
+
+/*
+ * call-seq:
+ * rat.denominator -> integer
+ *
+ * Returns the denominator (always positive).
+ *
+ * Rational(7).denominator #=> 1
+ * Rational(7, 1).denominator #=> 1
+ * Rational(9, -4).denominator #=> 4
+ * Rational(-2, -10).denominator #=> 5
+ */
+static VALUE
+nurat_denominator(VALUE self)
+{
+ get_dat1(self);
+ return dat->den;
+}
+
+/*
+ * call-seq:
+ * -self -> rational
+ *
+ * Returns +self+, negated:
+ *
+ * -(1/3r) # => (-1/3)
+ * -(-1/3r) # => (1/3)
+ *
+ */
+VALUE
+rb_rational_uminus(VALUE self)
+{
+ const int unused = (RUBY_ASSERT(RB_TYPE_P(self, T_RATIONAL)), 0);
+ get_dat1(self);
+ (void)unused;
+ return f_rational_new2(CLASS_OF(self), rb_int_uminus(dat->num), dat->den);
+}
+
+#ifndef NDEBUG
+#define f_imul f_imul_orig
+#endif
+
+inline static VALUE
+f_imul(long a, long b)
+{
+ VALUE r;
+
+ if (a == 0 || b == 0)
+ return ZERO;
+ else if (a == 1)
+ return LONG2NUM(b);
+ else if (b == 1)
+ return LONG2NUM(a);
+
+ if (MUL_OVERFLOW_LONG_P(a, b))
+ r = rb_big_mul(rb_int2big(a), rb_int2big(b));
+ else
+ r = LONG2NUM(a * b);
+ return r;
+}
+
+#ifndef NDEBUG
+#undef f_imul
+
+inline static VALUE
+f_imul(long x, long y)
+{
+ VALUE r = f_imul_orig(x, y);
+ RUBY_ASSERT(f_eqeq_p(r, f_mul(LONG2NUM(x), LONG2NUM(y))));
+ return r;
+}
+#endif
+
+inline static VALUE
+f_addsub(VALUE self, VALUE anum, VALUE aden, VALUE bnum, VALUE bden, int k)
+{
+ VALUE num, den;
+
+ if (FIXNUM_P(anum) && FIXNUM_P(aden) &&
+ FIXNUM_P(bnum) && FIXNUM_P(bden)) {
+ long an = FIX2LONG(anum);
+ long ad = FIX2LONG(aden);
+ long bn = FIX2LONG(bnum);
+ long bd = FIX2LONG(bden);
+ long ig = i_gcd(ad, bd);
+
+ VALUE g = LONG2NUM(ig);
+ VALUE a = f_imul(an, bd / ig);
+ VALUE b = f_imul(bn, ad / ig);
+ VALUE c;
+
+ if (k == '+')
+ c = rb_int_plus(a, b);
+ else
+ c = rb_int_minus(a, b);
+
+ b = rb_int_idiv(aden, g);
+ g = f_gcd(c, g);
+ num = rb_int_idiv(c, g);
+ a = rb_int_idiv(bden, g);
+ den = rb_int_mul(a, b);
+ }
+ else if (RB_INTEGER_TYPE_P(anum) && RB_INTEGER_TYPE_P(aden) &&
+ RB_INTEGER_TYPE_P(bnum) && RB_INTEGER_TYPE_P(bden)) {
+ VALUE g = f_gcd(aden, bden);
+ VALUE a = rb_int_mul(anum, rb_int_idiv(bden, g));
+ VALUE b = rb_int_mul(bnum, rb_int_idiv(aden, g));
+ VALUE c;
+
+ if (k == '+')
+ c = rb_int_plus(a, b);
+ else
+ c = rb_int_minus(a, b);
+
+ b = rb_int_idiv(aden, g);
+ g = f_gcd(c, g);
+ num = rb_int_idiv(c, g);
+ a = rb_int_idiv(bden, g);
+ den = rb_int_mul(a, b);
+ }
+ else {
+ double a = NUM2DBL(anum) / NUM2DBL(aden);
+ double b = NUM2DBL(bnum) / NUM2DBL(bden);
+ double c = k == '+' ? a + b : a - b;
+ return DBL2NUM(c);
+ }
+ return f_rational_new_no_reduce2(CLASS_OF(self), num, den);
+}
+
+static double nurat_to_double(VALUE self);
+/*
+ * call-seq:
+ * self + other -> numeric
+ *
+ * Returns the sum of +self+ and +other+:
+ *
+ * Rational(2, 3) + 0 # => (2/3)
+ * Rational(2, 3) + 1 # => (5/3)
+ * Rational(2, 3) + -1 # => (-1/3)
+ *
+ * Rational(2, 3) + Complex(1, 0) # => ((5/3)+0i)
+ *
+ * Rational(2, 3) + Rational(1, 1) # => (5/3)
+ * Rational(2, 3) + Rational(3, 2) # => (13/6)
+ * Rational(2, 3) + Rational(3.0, 2.0) # => (13/6)
+ * Rational(2, 3) + Rational(3.1, 2.1) # => (30399297484750849/14186338826217063)
+ *
+ * For a computation involving Floats, the result may be inexact (see Float#+):
+ *
+ * Rational(2, 3) + 1.0 # => 1.6666666666666665
+ * Rational(2, 3) + Complex(1.0, 0.0) # => (1.6666666666666665+0.0i)
+ *
+ */
+VALUE
+rb_rational_plus(VALUE self, VALUE other)
+{
+ if (RB_INTEGER_TYPE_P(other)) {
+ {
+ get_dat1(self);
+
+ return f_rational_new_no_reduce2(CLASS_OF(self),
+ rb_int_plus(dat->num, rb_int_mul(other, dat->den)),
+ dat->den);
+ }
+ }
+ else if (RB_FLOAT_TYPE_P(other)) {
+ return DBL2NUM(nurat_to_double(self) + RFLOAT_VALUE(other));
+ }
+ else if (RB_TYPE_P(other, T_RATIONAL)) {
+ {
+ get_dat2(self, other);
+
+ return f_addsub(self,
+ adat->num, adat->den,
+ bdat->num, bdat->den, '+');
+ }
+ }
+ else {
+ return rb_num_coerce_bin(self, other, '+');
+ }
+}
+
+/*
+ * call-seq:
+ * self - other -> numeric
+ *
+ * Returns the difference of +self+ and +other+:
+ *
+ * Rational(2, 3) - Rational(2, 3) #=> (0/1)
+ * Rational(900) - Rational(1) #=> (899/1)
+ * Rational(-2, 9) - Rational(-9, 2) #=> (77/18)
+ * Rational(9, 8) - 4 #=> (-23/8)
+ * Rational(20, 9) - 9.8 #=> -7.577777777777778
+ */
+VALUE
+rb_rational_minus(VALUE self, VALUE other)
+{
+ if (RB_INTEGER_TYPE_P(other)) {
+ {
+ get_dat1(self);
+
+ return f_rational_new_no_reduce2(CLASS_OF(self),
+ rb_int_minus(dat->num, rb_int_mul(other, dat->den)),
+ dat->den);
+ }
+ }
+ else if (RB_FLOAT_TYPE_P(other)) {
+ return DBL2NUM(nurat_to_double(self) - RFLOAT_VALUE(other));
+ }
+ else if (RB_TYPE_P(other, T_RATIONAL)) {
+ {
+ get_dat2(self, other);
+
+ return f_addsub(self,
+ adat->num, adat->den,
+ bdat->num, bdat->den, '-');
+ }
+ }
+ else {
+ return rb_num_coerce_bin(self, other, '-');
+ }
+}
+
+inline static VALUE
+f_muldiv(VALUE self, VALUE anum, VALUE aden, VALUE bnum, VALUE bden, int k)
+{
+ VALUE num, den;
+
+ RUBY_ASSERT(RB_TYPE_P(self, T_RATIONAL));
+
+ /* Integer#** can return Rational with Float right now */
+ if (RB_FLOAT_TYPE_P(anum) || RB_FLOAT_TYPE_P(aden) ||
+ RB_FLOAT_TYPE_P(bnum) || RB_FLOAT_TYPE_P(bden)) {
+ double an = NUM2DBL(anum), ad = NUM2DBL(aden);
+ double bn = NUM2DBL(bnum), bd = NUM2DBL(bden);
+ double x = (an * bn) / (ad * bd);
+ return DBL2NUM(x);
+ }
+
+ RUBY_ASSERT(RB_INTEGER_TYPE_P(anum));
+ RUBY_ASSERT(RB_INTEGER_TYPE_P(aden));
+ RUBY_ASSERT(RB_INTEGER_TYPE_P(bnum));
+ RUBY_ASSERT(RB_INTEGER_TYPE_P(bden));
+
+ if (k == '/') {
+ VALUE t;
+
+ if (INT_NEGATIVE_P(bnum)) {
+ anum = rb_int_uminus(anum);
+ bnum = rb_int_uminus(bnum);
+ }
+ t = bnum;
+ bnum = bden;
+ bden = t;
+ }
+
+ if (FIXNUM_P(anum) && FIXNUM_P(aden) &&
+ FIXNUM_P(bnum) && FIXNUM_P(bden)) {
+ long an = FIX2LONG(anum);
+ long ad = FIX2LONG(aden);
+ long bn = FIX2LONG(bnum);
+ long bd = FIX2LONG(bden);
+ long g1 = i_gcd(an, bd);
+ long g2 = i_gcd(ad, bn);
+
+ num = f_imul(an / g1, bn / g2);
+ den = f_imul(ad / g2, bd / g1);
+ }
+ else {
+ VALUE g1 = f_gcd(anum, bden);
+ VALUE g2 = f_gcd(aden, bnum);
+
+ num = rb_int_mul(rb_int_idiv(anum, g1), rb_int_idiv(bnum, g2));
+ den = rb_int_mul(rb_int_idiv(aden, g2), rb_int_idiv(bden, g1));
+ }
+ return f_rational_new_no_reduce2(CLASS_OF(self), num, den);
+}
+
+/*
+ * call-seq:
+ * self * other -> numeric
+ *
+ * Returns the numeric product of +self+ and +other+:
+ *
+ * Rational(9, 8) * 4 #=> (9/2)
+ * Rational(20, 9) * 9.8 #=> 21.77777777777778
+ * Rational(9, 8) * Complex(1, 2) # => ((9/8)+(9/4)*i)
+ * Rational(2, 3) * Rational(2, 3) #=> (4/9)
+ * Rational(900) * Rational(1) #=> (900/1)
+ * Rational(-2, 9) * Rational(-9, 2) #=> (1/1)
+ *
+ */
+VALUE
+rb_rational_mul(VALUE self, VALUE other)
+{
+ if (RB_INTEGER_TYPE_P(other)) {
+ {
+ get_dat1(self);
+
+ return f_muldiv(self,
+ dat->num, dat->den,
+ other, ONE, '*');
+ }
+ }
+ else if (RB_FLOAT_TYPE_P(other)) {
+ return DBL2NUM(nurat_to_double(self) * RFLOAT_VALUE(other));
+ }
+ else if (RB_TYPE_P(other, T_RATIONAL)) {
+ {
+ get_dat2(self, other);
+
+ return f_muldiv(self,
+ adat->num, adat->den,
+ bdat->num, bdat->den, '*');
+ }
+ }
+ else {
+ return rb_num_coerce_bin(self, other, '*');
+ }
+}
+
+/*
+ * call-seq:
+ * self / other -> numeric
+ *
+ * Returns the quotient of +self+ and +other+:
+ *
+ * Rational(2, 3) / Rational(2, 3) #=> (1/1)
+ * Rational(900) / Rational(1) #=> (900/1)
+ * Rational(-2, 9) / Rational(-9, 2) #=> (4/81)
+ * Rational(9, 8) / 4 #=> (9/32)
+ * Rational(20, 9) / 9.8 #=> 0.22675736961451246
+ */
+VALUE
+rb_rational_div(VALUE self, VALUE other)
+{
+ if (RB_INTEGER_TYPE_P(other)) {
+ if (f_zero_p(other))
+ rb_num_zerodiv();
+ {
+ get_dat1(self);
+
+ return f_muldiv(self,
+ dat->num, dat->den,
+ other, ONE, '/');
+ }
+ }
+ else if (RB_FLOAT_TYPE_P(other)) {
+ VALUE v = nurat_to_f(self);
+ return rb_flo_div_flo(v, other);
+ }
+ else if (RB_TYPE_P(other, T_RATIONAL)) {
+ if (f_zero_p(other))
+ rb_num_zerodiv();
+ {
+ get_dat2(self, other);
+
+ if (f_one_p(self))
+ return f_rational_new_no_reduce2(CLASS_OF(self),
+ bdat->den, bdat->num);
+
+ return f_muldiv(self,
+ adat->num, adat->den,
+ bdat->num, bdat->den, '/');
+ }
+ }
+ else {
+ return rb_num_coerce_bin(self, other, '/');
+ }
+}
+
+/*
+ * call-seq:
+ * rat.fdiv(numeric) -> float
+ *
+ * Performs division and returns the value as a Float.
+ *
+ * Rational(2, 3).fdiv(1) #=> 0.6666666666666666
+ * Rational(2, 3).fdiv(0.5) #=> 1.3333333333333333
+ * Rational(2).fdiv(3) #=> 0.6666666666666666
+ */
+static VALUE
+nurat_fdiv(VALUE self, VALUE other)
+{
+ VALUE div;
+ if (f_zero_p(other))
+ return rb_rational_div(self, rb_float_new(0.0));
+ if (FIXNUM_P(other) && other == LONG2FIX(1))
+ return nurat_to_f(self);
+ div = rb_rational_div(self, other);
+ if (RB_TYPE_P(div, T_RATIONAL))
+ return nurat_to_f(div);
+ if (RB_FLOAT_TYPE_P(div))
+ return div;
+ return rb_funcall(div, idTo_f, 0);
+}
+
+/*
+ * call-seq:
+ * self ** exponent -> numeric
+ *
+ * Returns +self+ raised to the power +exponent+:
+ *
+ * Rational(2) ** Rational(3) #=> (8/1)
+ * Rational(10) ** -2 #=> (1/100)
+ * Rational(10) ** -2.0 #=> 0.01
+ * Rational(-4) ** Rational(1, 2) #=> (0.0+2.0i)
+ * Rational(1, 2) ** 0 #=> (1/1)
+ * Rational(1, 2) ** 0.0 #=> 1.0
+ */
+VALUE
+rb_rational_pow(VALUE self, VALUE other)
+{
+ if (k_numeric_p(other) && k_exact_zero_p(other))
+ return f_rational_new_bang1(CLASS_OF(self), ONE);
+
+ if (k_rational_p(other)) {
+ get_dat1(other);
+
+ if (f_one_p(dat->den))
+ other = dat->num; /* c14n */
+ }
+
+ /* Deal with special cases of 0**n and 1**n */
+ if (k_numeric_p(other) && k_exact_p(other)) {
+ get_dat1(self);
+ if (f_one_p(dat->den)) {
+ if (f_one_p(dat->num)) {
+ return f_rational_new_bang1(CLASS_OF(self), ONE);
+ }
+ else if (f_minus_one_p(dat->num) && RB_INTEGER_TYPE_P(other)) {
+ return f_rational_new_bang1(CLASS_OF(self), INT2FIX(rb_int_odd_p(other) ? -1 : 1));
+ }
+ else if (INT_ZERO_P(dat->num)) {
+ if (rb_num_negative_p(other)) {
+ rb_num_zerodiv();
+ }
+ else {
+ return f_rational_new_bang1(CLASS_OF(self), ZERO);
+ }
+ }
+ }
+ }
+
+ /* General case */
+ if (FIXNUM_P(other)) {
+ {
+ VALUE num, den;
+
+ get_dat1(self);
+
+ if (INT_POSITIVE_P(other)) {
+ num = rb_int_pow(dat->num, other);
+ den = rb_int_pow(dat->den, other);
+ }
+ else if (INT_NEGATIVE_P(other)) {
+ num = rb_int_pow(dat->den, rb_int_uminus(other));
+ den = rb_int_pow(dat->num, rb_int_uminus(other));
+ }
+ else {
+ num = ONE;
+ den = ONE;
+ }
+ if (RB_FLOAT_TYPE_P(num)) { /* infinity due to overflow */
+ if (RB_FLOAT_TYPE_P(den))
+ return DBL2NUM(nan(""));
+ return num;
+ }
+ if (RB_FLOAT_TYPE_P(den)) { /* infinity due to overflow */
+ num = ZERO;
+ den = ONE;
+ }
+ return f_rational_new2(CLASS_OF(self), num, den);
+ }
+ }
+ else if (RB_BIGNUM_TYPE_P(other)) {
+ rb_raise(rb_eArgError, "exponent is too large");
+ }
+ else if (RB_FLOAT_TYPE_P(other) || RB_TYPE_P(other, T_RATIONAL)) {
+ return rb_float_pow(nurat_to_f(self), other);
+ }
+ else {
+ return rb_num_coerce_bin(self, other, idPow);
+ }
+}
+#define nurat_expt rb_rational_pow
+
+/*
+ * call-seq:
+ * self <=> other -> -1, 0, 1, or nil
+ *
+ * Compares +self+ and +other+.
+ *
+ * Returns:
+ *
+ * - +-1+, if +self+ is less than +other+.
+ * - +0+, if the two values are the same.
+ * - +1+, if +self+ is greater than +other+.
+ * - +nil+, if the two values are incomparable.
+ *
+ * Examples:
+ *
+ * Rational(2, 3) <=> Rational(4, 3) # => -1
+ * Rational(2, 1) <=> Rational(2, 1) # => 0
+ * Rational(2, 1) <=> 2 # => 0
+ * Rational(2, 1) <=> 2.0 # => 0
+ * Rational(2, 1) <=> Complex(2, 0) # => 0
+ * Rational(4, 3) <=> Rational(2, 3) # => 1
+ * Rational(4, 3) <=> :foo # => nil
+ *
+ * \Class \Rational includes module Comparable,
+ * each of whose methods uses Rational#<=> for comparison.
+ *
+ */
+VALUE
+rb_rational_cmp(VALUE self, VALUE other)
+{
+ switch (TYPE(other)) {
+ case T_FIXNUM:
+ case T_BIGNUM:
+ {
+ get_dat1(self);
+
+ if (dat->den == LONG2FIX(1))
+ return rb_int_cmp(dat->num, other); /* c14n */
+ other = f_rational_new_bang1(CLASS_OF(self), other);
+ /* FALLTHROUGH */
+ }
+
+ case T_RATIONAL:
+ {
+ VALUE num1, num2;
+
+ get_dat2(self, other);
+
+ if (FIXNUM_P(adat->num) && FIXNUM_P(adat->den) &&
+ FIXNUM_P(bdat->num) && FIXNUM_P(bdat->den)) {
+ num1 = f_imul(FIX2LONG(adat->num), FIX2LONG(bdat->den));
+ num2 = f_imul(FIX2LONG(bdat->num), FIX2LONG(adat->den));
+ }
+ else {
+ num1 = rb_int_mul(adat->num, bdat->den);
+ num2 = rb_int_mul(bdat->num, adat->den);
+ }
+ return rb_int_cmp(rb_int_minus(num1, num2), ZERO);
+ }
+
+ case T_FLOAT:
+ return rb_dbl_cmp(nurat_to_double(self), RFLOAT_VALUE(other));
+
+ default:
+ return rb_num_coerce_cmp(self, other, idCmp);
+ }
+}
+
+/*
+ * call-seq:
+ * self == other -> true or false
+ *
+ * Returns whether +self+ and +other+ are numerically equal:
+ *
+ * Rational(2, 3) == Rational(2, 3) #=> true
+ * Rational(5) == 5 #=> true
+ * Rational(0) == 0.0 #=> true
+ * Rational('1/3') == 0.33 #=> false
+ * Rational('1/2') == '1/2' #=> false
+ */
+static VALUE
+nurat_eqeq_p(VALUE self, VALUE other)
+{
+ if (RB_INTEGER_TYPE_P(other)) {
+ get_dat1(self);
+
+ if (RB_INTEGER_TYPE_P(dat->num) && RB_INTEGER_TYPE_P(dat->den)) {
+ if (INT_ZERO_P(dat->num) && INT_ZERO_P(other))
+ return Qtrue;
+
+ if (!FIXNUM_P(dat->den))
+ return Qfalse;
+ if (FIX2LONG(dat->den) != 1)
+ return Qfalse;
+ return rb_int_equal(dat->num, other);
+ }
+ else {
+ const double d = nurat_to_double(self);
+ return RBOOL(FIXNUM_ZERO_P(rb_dbl_cmp(d, NUM2DBL(other))));
+ }
+ }
+ else if (RB_FLOAT_TYPE_P(other)) {
+ const double d = nurat_to_double(self);
+ return RBOOL(FIXNUM_ZERO_P(rb_dbl_cmp(d, RFLOAT_VALUE(other))));
+ }
+ else if (RB_TYPE_P(other, T_RATIONAL)) {
+ {
+ get_dat2(self, other);
+
+ if (INT_ZERO_P(adat->num) && INT_ZERO_P(bdat->num))
+ return Qtrue;
+
+ return RBOOL(rb_int_equal(adat->num, bdat->num) &&
+ rb_int_equal(adat->den, bdat->den));
+ }
+ }
+ else {
+ return rb_equal(other, self);
+ }
+}
+
+/* :nodoc: */
+static VALUE
+nurat_coerce(VALUE self, VALUE other)
+{
+ if (RB_INTEGER_TYPE_P(other)) {
+ return rb_assoc_new(f_rational_new_bang1(CLASS_OF(self), other), self);
+ }
+ else if (RB_FLOAT_TYPE_P(other)) {
+ return rb_assoc_new(other, nurat_to_f(self));
+ }
+ else if (RB_TYPE_P(other, T_RATIONAL)) {
+ return rb_assoc_new(other, self);
+ }
+ else if (RB_TYPE_P(other, T_COMPLEX)) {
+ if (!k_exact_zero_p(RCOMPLEX(other)->imag))
+ return rb_assoc_new(other, rb_Complex(self, INT2FIX(0)));
+ other = RCOMPLEX(other)->real;
+ if (RB_FLOAT_TYPE_P(other)) {
+ other = float_to_r(other);
+ RBASIC_SET_CLASS(other, CLASS_OF(self));
+ }
+ else {
+ other = f_rational_new_bang1(CLASS_OF(self), other);
+ }
+ return rb_assoc_new(other, self);
+ }
+
+ rb_raise(rb_eTypeError, "%s can't be coerced into %s",
+ rb_obj_classname(other), rb_obj_classname(self));
+ return Qnil;
+}
+
+/*
+ * call-seq:
+ * rat.positive? -> true or false
+ *
+ * Returns +true+ if +rat+ is greater than 0.
+ */
+static VALUE
+nurat_positive_p(VALUE self)
+{
+ get_dat1(self);
+ return RBOOL(INT_POSITIVE_P(dat->num));
+}
+
+/*
+ * call-seq:
+ * rat.negative? -> true or false
+ *
+ * Returns +true+ if +rat+ is less than 0.
+ */
+static VALUE
+nurat_negative_p(VALUE self)
+{
+ get_dat1(self);
+ return RBOOL(INT_NEGATIVE_P(dat->num));
+}
+
+/*
+ * call-seq:
+ * rat.abs -> rational
+ * rat.magnitude -> rational
+ *
+ * Returns the absolute value of +rat+.
+ *
+ * (1/2r).abs #=> (1/2)
+ * (-1/2r).abs #=> (1/2)
+ *
+ */
+
+VALUE
+rb_rational_abs(VALUE self)
+{
+ get_dat1(self);
+ if (INT_NEGATIVE_P(dat->num)) {
+ VALUE num = rb_int_abs(dat->num);
+ return nurat_s_canonicalize_internal_no_reduce(CLASS_OF(self), num, dat->den);
+ }
+ return self;
+}
+
+static VALUE
+nurat_floor(VALUE self)
+{
+ get_dat1(self);
+ return rb_int_idiv(dat->num, dat->den);
+}
+
+static VALUE
+nurat_ceil(VALUE self)
+{
+ get_dat1(self);
+ return rb_int_uminus(rb_int_idiv(rb_int_uminus(dat->num), dat->den));
+}
+
+/*
+ * call-seq:
+ * rat.to_i -> integer
+ *
+ * Returns the truncated value as an integer.
+ *
+ * Equivalent to Rational#truncate.
+ *
+ * Rational(2, 3).to_i #=> 0
+ * Rational(3).to_i #=> 3
+ * Rational(300.6).to_i #=> 300
+ * Rational(98, 71).to_i #=> 1
+ * Rational(-31, 2).to_i #=> -15
+ */
+static VALUE
+nurat_truncate(VALUE self)
+{
+ get_dat1(self);
+ if (INT_NEGATIVE_P(dat->num))
+ return rb_int_uminus(rb_int_idiv(rb_int_uminus(dat->num), dat->den));
+ return rb_int_idiv(dat->num, dat->den);
+}
+
+static VALUE
+nurat_round_half_up(VALUE self)
+{
+ VALUE num, den, neg;
+
+ get_dat1(self);
+
+ num = dat->num;
+ den = dat->den;
+ neg = INT_NEGATIVE_P(num);
+
+ if (neg)
+ num = rb_int_uminus(num);
+
+ num = rb_int_plus(rb_int_mul(num, TWO), den);
+ den = rb_int_mul(den, TWO);
+ num = rb_int_idiv(num, den);
+
+ if (neg)
+ num = rb_int_uminus(num);
+
+ return num;
+}
+
+static VALUE
+nurat_round_half_down(VALUE self)
+{
+ VALUE num, den, neg;
+
+ get_dat1(self);
+
+ num = dat->num;
+ den = dat->den;
+ neg = INT_NEGATIVE_P(num);
+
+ if (neg)
+ num = rb_int_uminus(num);
+
+ num = rb_int_plus(rb_int_mul(num, TWO), den);
+ num = rb_int_minus(num, ONE);
+ den = rb_int_mul(den, TWO);
+ num = rb_int_idiv(num, den);
+
+ if (neg)
+ num = rb_int_uminus(num);
+
+ return num;
+}
+
+static VALUE
+nurat_round_half_even(VALUE self)
+{
+ VALUE num, den, neg, qr;
+
+ get_dat1(self);
+
+ num = dat->num;
+ den = dat->den;
+ neg = INT_NEGATIVE_P(num);
+
+ if (neg)
+ num = rb_int_uminus(num);
+
+ num = rb_int_plus(rb_int_mul(num, TWO), den);
+ den = rb_int_mul(den, TWO);
+ qr = rb_int_divmod(num, den);
+ num = RARRAY_AREF(qr, 0);
+ if (INT_ZERO_P(RARRAY_AREF(qr, 1)))
+ num = rb_int_and(num, LONG2FIX(((int)~1)));
+
+ if (neg)
+ num = rb_int_uminus(num);
+
+ return num;
+}
+
+static VALUE
+f_round_common(int argc, VALUE *argv, VALUE self, VALUE (*func)(VALUE))
+{
+ VALUE n, b, s;
+
+ if (rb_check_arity(argc, 0, 1) == 0)
+ return (*func)(self);
+
+ n = argv[0];
+
+ if (!k_integer_p(n))
+ rb_raise(rb_eTypeError, "not an integer");
+
+ b = f_expt10(n);
+ s = rb_rational_mul(self, b);
+
+ if (k_float_p(s)) {
+ if (INT_NEGATIVE_P(n))
+ return ZERO;
+ return self;
+ }
+
+ if (!k_rational_p(s)) {
+ s = f_rational_new_bang1(CLASS_OF(self), s);
+ }
+
+ s = (*func)(s);
+
+ s = rb_rational_div(f_rational_new_bang1(CLASS_OF(self), s), b);
+
+ if (RB_TYPE_P(s, T_RATIONAL) && FIX2INT(rb_int_cmp(n, ONE)) < 0)
+ s = nurat_truncate(s);
+
+ return s;
+}
+
+VALUE
+rb_rational_floor(VALUE self, int ndigits)
+{
+ if (ndigits == 0) {
+ return nurat_floor(self);
+ }
+ else {
+ VALUE n = INT2NUM(ndigits);
+ return f_round_common(1, &n, self, nurat_floor);
+ }
+}
+
+/*
+ * call-seq:
+ * rat.floor([ndigits]) -> integer or rational
+ *
+ * Returns the largest number less than or equal to +rat+ with
+ * a precision of +ndigits+ decimal digits (default: 0).
+ *
+ * When the precision is negative, the returned value is an integer
+ * with at least <code>ndigits.abs</code> trailing zeros.
+ *
+ * Returns a rational when +ndigits+ is positive,
+ * otherwise returns an integer.
+ *
+ * Rational(3).floor #=> 3
+ * Rational(2, 3).floor #=> 0
+ * Rational(-3, 2).floor #=> -2
+ *
+ * # decimal - 1 2 3 . 4 5 6
+ * # ^ ^ ^ ^ ^ ^
+ * # precision -3 -2 -1 0 +1 +2
+ *
+ * Rational('-123.456').floor(+1).to_f #=> -123.5
+ * Rational('-123.456').floor(-1) #=> -130
+ */
+static VALUE
+nurat_floor_n(int argc, VALUE *argv, VALUE self)
+{
+ return f_round_common(argc, argv, self, nurat_floor);
+}
+
+/*
+ * call-seq:
+ * rat.ceil([ndigits]) -> integer or rational
+ *
+ * Returns the smallest number greater than or equal to +rat+ with
+ * a precision of +ndigits+ decimal digits (default: 0).
+ *
+ * When the precision is negative, the returned value is an integer
+ * with at least <code>ndigits.abs</code> trailing zeros.
+ *
+ * Returns a rational when +ndigits+ is positive,
+ * otherwise returns an integer.
+ *
+ * Rational(3).ceil #=> 3
+ * Rational(2, 3).ceil #=> 1
+ * Rational(-3, 2).ceil #=> -1
+ *
+ * # decimal - 1 2 3 . 4 5 6
+ * # ^ ^ ^ ^ ^ ^
+ * # precision -3 -2 -1 0 +1 +2
+ *
+ * Rational('-123.456').ceil(+1).to_f #=> -123.4
+ * Rational('-123.456').ceil(-1) #=> -120
+ */
+static VALUE
+nurat_ceil_n(int argc, VALUE *argv, VALUE self)
+{
+ return f_round_common(argc, argv, self, nurat_ceil);
+}
+
+/*
+ * call-seq:
+ * rat.truncate([ndigits]) -> integer or rational
+ *
+ * Returns +rat+ truncated (toward zero) to
+ * a precision of +ndigits+ decimal digits (default: 0).
+ *
+ * When the precision is negative, the returned value is an integer
+ * with at least <code>ndigits.abs</code> trailing zeros.
+ *
+ * Returns a rational when +ndigits+ is positive,
+ * otherwise returns an integer.
+ *
+ * Rational(3).truncate #=> 3
+ * Rational(2, 3).truncate #=> 0
+ * Rational(-3, 2).truncate #=> -1
+ *
+ * # decimal - 1 2 3 . 4 5 6
+ * # ^ ^ ^ ^ ^ ^
+ * # precision -3 -2 -1 0 +1 +2
+ *
+ * Rational('-123.456').truncate(+1).to_f #=> -123.4
+ * Rational('-123.456').truncate(-1) #=> -120
+ */
+static VALUE
+nurat_truncate_n(int argc, VALUE *argv, VALUE self)
+{
+ return f_round_common(argc, argv, self, nurat_truncate);
+}
+
+/*
+ * call-seq:
+ * rat.round([ndigits] [, half: mode]) -> integer or rational
+ *
+ * Returns +rat+ rounded to the nearest value with
+ * a precision of +ndigits+ decimal digits (default: 0).
+ *
+ * When the precision is negative, the returned value is an integer
+ * with at least <code>ndigits.abs</code> trailing zeros.
+ *
+ * Returns a rational when +ndigits+ is positive,
+ * otherwise returns an integer.
+ *
+ * Rational(3).round #=> 3
+ * Rational(2, 3).round #=> 1
+ * Rational(-3, 2).round #=> -2
+ *
+ * # decimal - 1 2 3 . 4 5 6
+ * # ^ ^ ^ ^ ^ ^
+ * # precision -3 -2 -1 0 +1 +2
+ *
+ * Rational('-123.456').round(+1).to_f #=> -123.5
+ * Rational('-123.456').round(-1) #=> -120
+ *
+ * The optional +half+ keyword argument is available
+ * similar to Float#round.
+ *
+ * Rational(25, 100).round(1, half: :up) #=> (3/10)
+ * Rational(25, 100).round(1, half: :down) #=> (1/5)
+ * Rational(25, 100).round(1, half: :even) #=> (1/5)
+ * Rational(35, 100).round(1, half: :up) #=> (2/5)
+ * Rational(35, 100).round(1, half: :down) #=> (3/10)
+ * Rational(35, 100).round(1, half: :even) #=> (2/5)
+ * Rational(-25, 100).round(1, half: :up) #=> (-3/10)
+ * Rational(-25, 100).round(1, half: :down) #=> (-1/5)
+ * Rational(-25, 100).round(1, half: :even) #=> (-1/5)
+ */
+static VALUE
+nurat_round_n(int argc, VALUE *argv, VALUE self)
+{
+ VALUE opt;
+ enum ruby_num_rounding_mode mode = (
+ argc = rb_scan_args(argc, argv, "*:", NULL, &opt),
+ rb_num_get_rounding_option(opt));
+ VALUE (*round_func)(VALUE) = ROUND_FUNC(mode, nurat_round);
+ return f_round_common(argc, argv, self, round_func);
+}
+
+VALUE
+rb_flo_round_by_rational(int argc, VALUE *argv, VALUE num)
+{
+ return nurat_to_f(nurat_round_n(argc, argv, float_to_r(num)));
+}
+
+static double
+nurat_to_double(VALUE self)
+{
+ get_dat1(self);
+ if (!RB_INTEGER_TYPE_P(dat->num) || !RB_INTEGER_TYPE_P(dat->den)) {
+ return NUM2DBL(dat->num) / NUM2DBL(dat->den);
+ }
+ return rb_int_fdiv_double(dat->num, dat->den);
+}
+
+/*
+ * call-seq:
+ * rat.to_f -> float
+ *
+ * Returns the value as a Float.
+ *
+ * Rational(2).to_f #=> 2.0
+ * Rational(9, 4).to_f #=> 2.25
+ * Rational(-3, 4).to_f #=> -0.75
+ * Rational(20, 3).to_f #=> 6.666666666666667
+ */
+static VALUE
+nurat_to_f(VALUE self)
+{
+ return DBL2NUM(nurat_to_double(self));
+}
+
+/*
+ * call-seq:
+ * rat.to_r -> self
+ *
+ * Returns self.
+ *
+ * Rational(2).to_r #=> (2/1)
+ * Rational(-8, 6).to_r #=> (-4/3)
+ */
+static VALUE
+nurat_to_r(VALUE self)
+{
+ return self;
+}
+
+#define id_ceil rb_intern("ceil")
+static VALUE
+f_ceil(VALUE x)
+{
+ if (RB_INTEGER_TYPE_P(x))
+ return x;
+ if (RB_FLOAT_TYPE_P(x))
+ return rb_float_ceil(x, 0);
+
+ return rb_funcall(x, id_ceil, 0);
+}
+
+#define id_quo idQuo
+static VALUE
+f_quo(VALUE x, VALUE y)
+{
+ if (RB_INTEGER_TYPE_P(x))
+ return rb_int_div(x, y);
+ if (RB_FLOAT_TYPE_P(x))
+ return DBL2NUM(RFLOAT_VALUE(x) / RFLOAT_VALUE(y));
+
+ return rb_funcallv(x, id_quo, 1, &y);
+}
+
+#define f_reciprocal(x) f_quo(ONE, (x))
+
+/*
+ The algorithm here is the method described in CLISP. Bruno Haible has
+ graciously given permission to use this algorithm. He says, "You can use
+ it, if you present the following explanation of the algorithm."
+
+ Algorithm (recursively presented):
+ If x is a rational number, return x.
+ If x = 0.0, return 0.
+ If x < 0.0, return (- (rationalize (- x))).
+ If x > 0.0:
+ Call (integer-decode-float x). It returns a m,e,s=1 (mantissa,
+ exponent, sign).
+ If m = 0 or e >= 0: return x = m*2^e.
+ Search a rational number between a = (m-1/2)*2^e and b = (m+1/2)*2^e
+ with smallest possible numerator and denominator.
+ Note 1: If m is a power of 2, we ought to take a = (m-1/4)*2^e.
+ But in this case the result will be x itself anyway, regardless of
+ the choice of a. Therefore we can simply ignore this case.
+ Note 2: At first, we need to consider the closed interval [a,b].
+ but since a and b have the denominator 2^(|e|+1) whereas x itself
+ has a denominator <= 2^|e|, we can restrict the search to the open
+ interval (a,b).
+ So, for given a and b (0 < a < b) we are searching a rational number
+ y with a <= y <= b.
+ Recursive algorithm fraction_between(a,b):
+ c := (ceiling a)
+ if c < b
+ then return c ; because a <= c < b, c integer
+ else
+ ; a is not integer (otherwise we would have had c = a < b)
+ k := c-1 ; k = floor(a), k < a < b <= k+1
+ return y = k + 1/fraction_between(1/(b-k), 1/(a-k))
+ ; note 1 <= 1/(b-k) < 1/(a-k)
+
+ You can see that we are actually computing a continued fraction expansion.
+
+ Algorithm (iterative):
+ If x is rational, return x.
+ Call (integer-decode-float x). It returns a m,e,s (mantissa,
+ exponent, sign).
+ If m = 0 or e >= 0, return m*2^e*s. (This includes the case x = 0.0.)
+ Create rational numbers a := (2*m-1)*2^(e-1) and b := (2*m+1)*2^(e-1)
+ (positive and already in lowest terms because the denominator is a
+ power of two and the numerator is odd).
+ Start a continued fraction expansion
+ p[-1] := 0, p[0] := 1, q[-1] := 1, q[0] := 0, i := 0.
+ Loop
+ c := (ceiling a)
+ if c >= b
+ then k := c-1, partial_quotient(k), (a,b) := (1/(b-k),1/(a-k)),
+ goto Loop
+ finally partial_quotient(c).
+ Here partial_quotient(c) denotes the iteration
+ i := i+1, p[i] := c*p[i-1]+p[i-2], q[i] := c*q[i-1]+q[i-2].
+ At the end, return s * (p[i]/q[i]).
+ This rational number is already in lowest terms because
+ p[i]*q[i-1]-p[i-1]*q[i] = (-1)^i.
+*/
+
+static void
+nurat_rationalize_internal(VALUE a, VALUE b, VALUE *p, VALUE *q)
+{
+ VALUE c, k, t, p0, p1, p2, q0, q1, q2;
+
+ p0 = ZERO;
+ p1 = ONE;
+ q0 = ONE;
+ q1 = ZERO;
+
+ while (1) {
+ c = f_ceil(a);
+ if (f_lt_p(c, b))
+ break;
+ k = f_sub(c, ONE);
+ p2 = f_add(f_mul(k, p1), p0);
+ q2 = f_add(f_mul(k, q1), q0);
+ t = f_reciprocal(f_sub(b, k));
+ b = f_reciprocal(f_sub(a, k));
+ a = t;
+ p0 = p1;
+ q0 = q1;
+ p1 = p2;
+ q1 = q2;
+ }
+ *p = f_add(f_mul(c, p1), p0);
+ *q = f_add(f_mul(c, q1), q0);
+}
+
+/*
+ * call-seq:
+ * rat.rationalize -> self
+ * rat.rationalize(eps) -> rational
+ *
+ * Returns a simpler approximation of the value if the optional
+ * argument +eps+ is given (rat-|eps| <= result <= rat+|eps|),
+ * self otherwise.
+ *
+ * r = Rational(5033165, 16777216)
+ * r.rationalize #=> (5033165/16777216)
+ * r.rationalize(Rational('0.01')) #=> (3/10)
+ * r.rationalize(Rational('0.1')) #=> (1/3)
+ */
+static VALUE
+nurat_rationalize(int argc, VALUE *argv, VALUE self)
+{
+ VALUE e, a, b, p, q;
+ VALUE rat = self;
+ get_dat1(self);
+
+ if (rb_check_arity(argc, 0, 1) == 0)
+ return self;
+
+ e = f_abs(argv[0]);
+
+ if (INT_NEGATIVE_P(dat->num)) {
+ rat = f_rational_new2(RBASIC_CLASS(self), rb_int_uminus(dat->num), dat->den);
+ }
+
+ a = FIXNUM_ZERO_P(e) ? rat : rb_rational_minus(rat, e);
+ b = FIXNUM_ZERO_P(e) ? rat : rb_rational_plus(rat, e);
+
+ if (f_eqeq_p(a, b))
+ return self;
+
+ nurat_rationalize_internal(a, b, &p, &q);
+ if (rat != self) {
+ RATIONAL_SET_NUM(rat, rb_int_uminus(p));
+ RATIONAL_SET_DEN(rat, q);
+ return rat;
+ }
+ return f_rational_new2(CLASS_OF(self), p, q);
+}
+
+/* :nodoc: */
+st_index_t
+rb_rational_hash(VALUE self)
+{
+ st_index_t v, h[2];
+ VALUE n;
+
+ get_dat1(self);
+ n = rb_hash(dat->num);
+ h[0] = NUM2LONG(n);
+ n = rb_hash(dat->den);
+ h[1] = NUM2LONG(n);
+ v = rb_memhash(h, sizeof(h));
+ return v;
+}
+
+static VALUE
+nurat_hash(VALUE self)
+{
+ return ST2FIX(rb_rational_hash(self));
+}
+
+
+static VALUE
+f_format(VALUE self, VALUE (*func)(VALUE))
+{
+ VALUE s;
+ get_dat1(self);
+
+ s = (*func)(dat->num);
+ rb_str_cat2(s, "/");
+ rb_str_concat(s, (*func)(dat->den));
+
+ return s;
+}
+
+/*
+ * call-seq:
+ * rat.to_s -> string
+ *
+ * Returns the value as a string.
+ *
+ * Rational(2).to_s #=> "2/1"
+ * Rational(-8, 6).to_s #=> "-4/3"
+ * Rational('1/2').to_s #=> "1/2"
+ */
+static VALUE
+nurat_to_s(VALUE self)
+{
+ return f_format(self, f_to_s);
+}
+
+/*
+ * call-seq:
+ * rat.inspect -> string
+ *
+ * Returns the value as a string for inspection.
+ *
+ * Rational(2).inspect #=> "(2/1)"
+ * Rational(-8, 6).inspect #=> "(-4/3)"
+ * Rational('1/2').inspect #=> "(1/2)"
+ */
+static VALUE
+nurat_inspect(VALUE self)
+{
+ VALUE s;
+
+ s = rb_usascii_str_new2("(");
+ rb_str_concat(s, f_format(self, f_inspect));
+ rb_str_cat2(s, ")");
+
+ return s;
+}
+
+/* :nodoc: */
+static VALUE
+nurat_dumper(VALUE self)
+{
+ return self;
+}
+
+/* :nodoc: */
+static VALUE
+nurat_loader(VALUE self, VALUE a)
+{
+ VALUE num, den;
+
+ get_dat1(self);
+ num = rb_ivar_get(a, id_i_num);
+ den = rb_ivar_get(a, id_i_den);
+ nurat_int_check(num);
+ nurat_int_check(den);
+ nurat_canonicalize(&num, &den);
+ RATIONAL_SET_NUM((VALUE)dat, num);
+ RATIONAL_SET_DEN((VALUE)dat, den);
+ OBJ_FREEZE(self);
+
+ return self;
+}
+
+/* :nodoc: */
+static VALUE
+nurat_marshal_dump(VALUE self)
+{
+ VALUE a;
+ get_dat1(self);
+
+ a = rb_assoc_new(dat->num, dat->den);
+ rb_copy_generic_ivar(a, self);
+ return a;
+}
+
+/* :nodoc: */
+static VALUE
+nurat_marshal_load(VALUE self, VALUE a)
+{
+ VALUE num, den;
+
+ rb_check_frozen(self);
+
+ Check_Type(a, T_ARRAY);
+ if (RARRAY_LEN(a) != 2)
+ rb_raise(rb_eArgError, "marshaled rational must have an array whose length is 2 but %ld", RARRAY_LEN(a));
+
+ num = RARRAY_AREF(a, 0);
+ den = RARRAY_AREF(a, 1);
+ nurat_int_check(num);
+ nurat_int_check(den);
+ nurat_canonicalize(&num, &den);
+ rb_ivar_set(self, id_i_num, num);
+ rb_ivar_set(self, id_i_den, den);
+
+ return self;
+}
+
+VALUE
+rb_rational_reciprocal(VALUE x)
+{
+ get_dat1(x);
+ return nurat_convert(CLASS_OF(x), dat->den, dat->num, FALSE);
+}
+
+/*
+ * call-seq:
+ * int.gcd(other_int) -> integer
+ *
+ * Returns the greatest common divisor of the two integers.
+ * The result is always positive. 0.gcd(x) and x.gcd(0) return x.abs.
+ *
+ * 36.gcd(60) #=> 12
+ * 2.gcd(2) #=> 2
+ * 3.gcd(-7) #=> 1
+ * ((1<<31)-1).gcd((1<<61)-1) #=> 1
+ */
+VALUE
+rb_gcd(VALUE self, VALUE other)
+{
+ other = nurat_int_value(other);
+ return f_gcd(self, other);
+}
+
+/*
+ * call-seq:
+ * int.lcm(other_int) -> integer
+ *
+ * Returns the least common multiple of the two integers.
+ * The result is always positive. 0.lcm(x) and x.lcm(0) return zero.
+ *
+ * 36.lcm(60) #=> 180
+ * 2.lcm(2) #=> 2
+ * 3.lcm(-7) #=> 21
+ * ((1<<31)-1).lcm((1<<61)-1) #=> 4951760154835678088235319297
+ */
+VALUE
+rb_lcm(VALUE self, VALUE other)
+{
+ other = nurat_int_value(other);
+ return f_lcm(self, other);
+}
+
+/*
+ * call-seq:
+ * int.gcdlcm(other_int) -> array
+ *
+ * Returns an array with the greatest common divisor and
+ * the least common multiple of the two integers, [gcd, lcm].
+ *
+ * 36.gcdlcm(60) #=> [12, 180]
+ * 2.gcdlcm(2) #=> [2, 2]
+ * 3.gcdlcm(-7) #=> [1, 21]
+ * ((1<<31)-1).gcdlcm((1<<61)-1) #=> [1, 4951760154835678088235319297]
+ */
+VALUE
+rb_gcdlcm(VALUE self, VALUE other)
+{
+ other = nurat_int_value(other);
+ return rb_assoc_new(f_gcd(self, other), f_lcm(self, other));
+}
+
+VALUE
+rb_rational_raw(VALUE x, VALUE y)
+{
+ if (! RB_INTEGER_TYPE_P(x))
+ x = rb_to_int(x);
+ if (! RB_INTEGER_TYPE_P(y))
+ y = rb_to_int(y);
+ if (INT_NEGATIVE_P(y)) {
+ x = rb_int_uminus(x);
+ y = rb_int_uminus(y);
+ }
+ return nurat_s_new_internal(rb_cRational, x, y);
+}
+
+VALUE
+rb_rational_new(VALUE x, VALUE y)
+{
+ return nurat_s_canonicalize_internal(rb_cRational, x, y);
+}
+
+VALUE
+rb_Rational(VALUE x, VALUE y)
+{
+ VALUE a[2];
+ a[0] = x;
+ a[1] = y;
+ return nurat_s_convert(2, a, rb_cRational);
+}
+
+VALUE
+rb_rational_num(VALUE rat)
+{
+ return nurat_numerator(rat);
+}
+
+VALUE
+rb_rational_den(VALUE rat)
+{
+ return nurat_denominator(rat);
+}
+
+#define id_numerator rb_intern("numerator")
+#define f_numerator(x) rb_funcall((x), id_numerator, 0)
+
+#define id_denominator rb_intern("denominator")
+#define f_denominator(x) rb_funcall((x), id_denominator, 0)
+
+#define id_to_r idTo_r
+#define f_to_r(x) rb_funcall((x), id_to_r, 0)
+
+/*
+ * call-seq:
+ * num.numerator -> integer
+ *
+ * Returns the numerator.
+ */
+static VALUE
+numeric_numerator(VALUE self)
+{
+ return f_numerator(f_to_r(self));
+}
+
+/*
+ * call-seq:
+ * num.denominator -> integer
+ *
+ * Returns the denominator (always positive).
+ */
+static VALUE
+numeric_denominator(VALUE self)
+{
+ return f_denominator(f_to_r(self));
+}
+
+
+/*
+ * call-seq:
+ * num.quo(int_or_rat) -> rat
+ * num.quo(flo) -> flo
+ *
+ * Returns the most exact division (rational for integers, float for floats).
+ */
+
+VALUE
+rb_numeric_quo(VALUE x, VALUE y)
+{
+ if (RB_TYPE_P(x, T_COMPLEX)) {
+ return rb_complex_div(x, y);
+ }
+
+ if (RB_FLOAT_TYPE_P(y)) {
+ return rb_funcallv(x, idFdiv, 1, &y);
+ }
+
+ x = rb_convert_type(x, T_RATIONAL, "Rational", "to_r");
+ return rb_rational_div(x, y);
+}
+
+VALUE
+rb_rational_canonicalize(VALUE x)
+{
+ if (RB_TYPE_P(x, T_RATIONAL)) {
+ get_dat1(x);
+ if (f_one_p(dat->den)) return dat->num;
+ }
+ return x;
+}
+
+/*
+ * call-seq:
+ * flo.numerator -> integer
+ *
+ * Returns the numerator. The result is machine dependent.
+ *
+ * n = 0.3.numerator #=> 5404319552844595
+ * d = 0.3.denominator #=> 18014398509481984
+ * n.fdiv(d) #=> 0.3
+ *
+ * See also Float#denominator.
+ */
+VALUE
+rb_float_numerator(VALUE self)
+{
+ double d = RFLOAT_VALUE(self);
+ VALUE r;
+ if (!isfinite(d))
+ return self;
+ r = float_to_r(self);
+ return nurat_numerator(r);
+}
+
+/*
+ * call-seq:
+ * flo.denominator -> integer
+ *
+ * Returns the denominator (always positive). The result is machine
+ * dependent.
+ *
+ * See also Float#numerator.
+ */
+VALUE
+rb_float_denominator(VALUE self)
+{
+ double d = RFLOAT_VALUE(self);
+ VALUE r;
+ if (!isfinite(d))
+ return INT2FIX(1);
+ r = float_to_r(self);
+ return nurat_denominator(r);
+}
+
+/*
+ * call-seq:
+ * int.to_r -> rational
+ *
+ * Returns the value as a rational.
+ *
+ * 1.to_r #=> (1/1)
+ * (1<<64).to_r #=> (18446744073709551616/1)
+ */
+static VALUE
+integer_to_r(VALUE self)
+{
+ return rb_rational_new1(self);
+}
+
+/*
+ * call-seq:
+ * int.rationalize([eps]) -> rational
+ *
+ * Returns the value as a rational. The optional argument +eps+ is
+ * always ignored.
+ */
+static VALUE
+integer_rationalize(int argc, VALUE *argv, VALUE self)
+{
+ rb_check_arity(argc, 0, 1);
+ return integer_to_r(self);
+}
+
+static void
+float_decode_internal(VALUE self, VALUE *rf, int *n)
+{
+ double f;
+
+ f = frexp(RFLOAT_VALUE(self), n);
+ f = ldexp(f, DBL_MANT_DIG);
+ *n -= DBL_MANT_DIG;
+ *rf = rb_dbl2big(f);
+}
+
+/*
+ * call-seq:
+ * flt.to_r -> rational
+ *
+ * Returns the value as a rational.
+ *
+ * 2.0.to_r #=> (2/1)
+ * 2.5.to_r #=> (5/2)
+ * -0.75.to_r #=> (-3/4)
+ * 0.0.to_r #=> (0/1)
+ * 0.3.to_r #=> (5404319552844595/18014398509481984)
+ *
+ * NOTE: 0.3.to_r isn't the same as "0.3".to_r. The latter is
+ * equivalent to "3/10".to_r, but the former isn't so.
+ *
+ * 0.3.to_r == 3/10r #=> false
+ * "0.3".to_r == 3/10r #=> true
+ *
+ * See also Float#rationalize.
+ */
+static VALUE
+float_to_r(VALUE self)
+{
+ VALUE f;
+ int n;
+
+ float_decode_internal(self, &f, &n);
+#if FLT_RADIX == 2
+ if (n == 0)
+ return rb_rational_new1(f);
+ if (n > 0)
+ return rb_rational_new1(rb_int_lshift(f, INT2FIX(n)));
+ n = -n;
+ return rb_rational_new2(f, rb_int_lshift(ONE, INT2FIX(n)));
+#else
+ f = rb_int_mul(f, rb_int_pow(INT2FIX(FLT_RADIX), n));
+ if (RB_TYPE_P(f, T_RATIONAL))
+ return f;
+ return rb_rational_new1(f);
+#endif
+}
+
+VALUE
+rb_flt_rationalize_with_prec(VALUE flt, VALUE prec)
+{
+ VALUE e, a, b, p, q;
+
+ e = f_abs(prec);
+ a = f_sub(flt, e);
+ b = f_add(flt, e);
+
+ if (f_eqeq_p(a, b))
+ return float_to_r(flt);
+
+ nurat_rationalize_internal(a, b, &p, &q);
+ return rb_rational_new2(p, q);
+}
+
+VALUE
+rb_flt_rationalize(VALUE flt)
+{
+ VALUE a, b, f, p, q, den;
+ int n;
+
+ float_decode_internal(flt, &f, &n);
+ if (INT_ZERO_P(f) || n >= 0)
+ return rb_rational_new1(rb_int_lshift(f, INT2FIX(n)));
+
+ {
+ VALUE radix_times_f;
+
+ radix_times_f = rb_int_mul(INT2FIX(FLT_RADIX), f);
+#if FLT_RADIX == 2 && 0
+ den = rb_int_lshift(ONE, INT2FIX(1-n));
+#else
+ den = rb_int_positive_pow(FLT_RADIX, 1-n);
+#endif
+
+ a = rb_int_minus(radix_times_f, INT2FIX(FLT_RADIX - 1));
+ b = rb_int_plus(radix_times_f, INT2FIX(FLT_RADIX - 1));
+ }
+
+ if (f_eqeq_p(a, b))
+ return float_to_r(flt);
+
+ a = rb_rational_new2(a, den);
+ b = rb_rational_new2(b, den);
+ nurat_rationalize_internal(a, b, &p, &q);
+ return rb_rational_new2(p, q);
+}
+
+/*
+ * call-seq:
+ * flt.rationalize([eps]) -> rational
+ *
+ * Returns a simpler approximation of the value (flt-|eps| <= result
+ * <= flt+|eps|). If the optional argument +eps+ is not given,
+ * it will be chosen automatically.
+ *
+ * 0.3.rationalize #=> (3/10)
+ * 1.333.rationalize #=> (1333/1000)
+ * 1.333.rationalize(0.01) #=> (4/3)
+ *
+ * See also Float#to_r.
+ */
+static VALUE
+float_rationalize(int argc, VALUE *argv, VALUE self)
+{
+ double d = RFLOAT_VALUE(self);
+ VALUE rat;
+ int neg = d < 0.0;
+ if (neg) self = DBL2NUM(-d);
+
+ if (rb_check_arity(argc, 0, 1)) {
+ rat = rb_flt_rationalize_with_prec(self, argv[0]);
+ }
+ else {
+ rat = rb_flt_rationalize(self);
+ }
+ if (neg) RATIONAL_SET_NUM(rat, rb_int_uminus(RRATIONAL(rat)->num));
+ return rat;
+}
+
+inline static int
+issign(int c)
+{
+ return (c == '-' || c == '+');
+}
+
+static int
+read_sign(const char **s, const char *const e)
+{
+ int sign = '?';
+
+ if (*s < e && issign(**s)) {
+ sign = **s;
+ (*s)++;
+ }
+ return sign;
+}
+
+inline static int
+islettere(int c)
+{
+ return (c == 'e' || c == 'E');
+}
+
+static VALUE
+negate_num(VALUE num)
+{
+ if (FIXNUM_P(num)) {
+ return rb_int_uminus(num);
+ }
+ else {
+ BIGNUM_NEGATE(num);
+ return rb_big_norm(num);
+ }
+}
+
+static int
+read_num(const char **s, const char *const end, VALUE *num, VALUE *nexp)
+{
+ VALUE fp = ONE, exp, fn = ZERO, n = ZERO;
+ int expsign = 0, ok = 0;
+ char *e;
+
+ *nexp = ZERO;
+ *num = ZERO;
+ if (*s < end && **s != '.') {
+ n = rb_int_parse_cstr(*s, end-*s, &e, NULL,
+ 10, RB_INT_PARSE_UNDERSCORE);
+ if (NIL_P(n))
+ return 0;
+ *s = e;
+ *num = n;
+ ok = 1;
+ }
+
+ if (*s < end && **s == '.') {
+ size_t count = 0;
+
+ (*s)++;
+ fp = rb_int_parse_cstr(*s, end-*s, &e, &count,
+ 10, RB_INT_PARSE_UNDERSCORE);
+ if (NIL_P(fp))
+ return 1;
+ *s = e;
+ {
+ VALUE l = f_expt10(*nexp = SIZET2NUM(count));
+ n = n == ZERO ? fp : rb_int_plus(rb_int_mul(*num, l), fp);
+ *num = n;
+ fn = SIZET2NUM(count);
+ }
+ ok = 1;
+ }
+
+ if (ok && *s + 1 < end && islettere(**s)) {
+ (*s)++;
+ expsign = read_sign(s, end);
+ exp = rb_int_parse_cstr(*s, end-*s, &e, NULL,
+ 10, RB_INT_PARSE_UNDERSCORE);
+ if (NIL_P(exp))
+ return 1;
+ *s = e;
+ if (exp != ZERO) {
+ if (expsign == '-') {
+ if (fn != ZERO) exp = rb_int_plus(exp, fn);
+ }
+ else {
+ if (fn != ZERO) exp = rb_int_minus(exp, fn);
+ exp = negate_num(exp);
+ }
+ *nexp = exp;
+ }
+ }
+
+ return ok;
+}
+
+inline static const char *
+skip_ws(const char *s, const char *e)
+{
+ while (s < e && isspace((unsigned char)*s))
+ ++s;
+ return s;
+}
+
+static VALUE
+parse_rat(const char *s, const char *const e, int strict, int raise)
+{
+ int sign;
+ VALUE num, den, nexp, dexp;
+
+ s = skip_ws(s, e);
+ sign = read_sign(&s, e);
+
+ if (!read_num(&s, e, &num, &nexp)) {
+ if (strict) return Qnil;
+ return nurat_s_alloc(rb_cRational);
+ }
+ den = ONE;
+ if (s < e && *s == '/') {
+ s++;
+ if (!read_num(&s, e, &den, &dexp)) {
+ if (strict) return Qnil;
+ den = ONE;
+ }
+ else if (den == ZERO) {
+ if (!raise) return Qnil;
+ rb_num_zerodiv();
+ }
+ else if (strict && skip_ws(s, e) != e) {
+ return Qnil;
+ }
+ else {
+ nexp = rb_int_minus(nexp, dexp);
+ nurat_reduce(&num, &den);
+ }
+ }
+ else if (strict && skip_ws(s, e) != e) {
+ return Qnil;
+ }
+
+ if (nexp != ZERO) {
+ if (INT_NEGATIVE_P(nexp)) {
+ VALUE mul;
+ if (FIXNUM_P(nexp)) {
+ mul = f_expt10(LONG2NUM(-FIX2LONG(nexp)));
+ if (! RB_FLOAT_TYPE_P(mul)) {
+ num = rb_int_mul(num, mul);
+ goto reduce;
+ }
+ }
+ return sign == '-' ? DBL2NUM(-HUGE_VAL) : DBL2NUM(HUGE_VAL);
+ }
+ else {
+ VALUE div;
+ if (FIXNUM_P(nexp)) {
+ div = f_expt10(nexp);
+ if (! RB_FLOAT_TYPE_P(div)) {
+ den = rb_int_mul(den, div);
+ goto reduce;
+ }
+ }
+ return sign == '-' ? DBL2NUM(-0.0) : DBL2NUM(+0.0);
+ }
+ reduce:
+ nurat_reduce(&num, &den);
+ }
+
+ if (sign == '-') {
+ num = negate_num(num);
+ }
+
+ return rb_rational_raw(num, den);
+}
+
+static VALUE
+string_to_r_strict(VALUE self, int raise)
+{
+ VALUE num;
+
+ rb_must_asciicompat(self);
+
+ num = parse_rat(RSTRING_PTR(self), RSTRING_END(self), 1, raise);
+ if (NIL_P(num)) {
+ if (!raise) return Qnil;
+ rb_raise(rb_eArgError, "invalid value for convert(): %+"PRIsVALUE,
+ self);
+ }
+
+ if (RB_FLOAT_TYPE_P(num) && !FLOAT_ZERO_P(num)) {
+ if (!raise) return Qnil;
+ rb_raise(rb_eFloatDomainError, "Infinity");
+ }
+ return num;
+}
+
+/*
+ * call-seq:
+ * str.to_r -> rational
+ *
+ * Returns the result of interpreting leading characters in +self+ as a rational value:
+ *
+ * '123'.to_r # => (123/1) # Integer literal.
+ * '300/2'.to_r # => (150/1) # Rational literal.
+ * '-9.2'.to_r # => (-46/5) # Float literal.
+ * '-9.2e2'.to_r # => (-920/1) # Float literal.
+ *
+ * Ignores leading and trailing whitespace, and trailing non-numeric characters:
+ *
+ * ' 2 '.to_r # => (2/1)
+ * '21-Jun-09'.to_r # => (21/1)
+ *
+ * Returns \Rational zero if there are no leading numeric characters.
+ *
+ * 'BWV 1079'.to_r # => (0/1)
+ *
+ * NOTE: <tt>'0.3'.to_r</tt> is equivalent to <tt>3/10r</tt>,
+ * but is different from <tt>0.3.to_r</tt>:
+ *
+ * '0.3'.to_r # => (3/10)
+ * 3/10r # => (3/10)
+ * 0.3.to_r # => (5404319552844595/18014398509481984)
+ *
+ * Related: see {Converting to Non-String}[rdoc-ref:String@Converting+to+Non--5CString].
+ */
+static VALUE
+string_to_r(VALUE self)
+{
+ VALUE num;
+
+ rb_must_asciicompat(self);
+
+ num = parse_rat(RSTRING_PTR(self), RSTRING_END(self), 0, TRUE);
+
+ if (RB_FLOAT_TYPE_P(num) && !FLOAT_ZERO_P(num))
+ rb_raise(rb_eFloatDomainError, "Infinity");
+ return num;
+}
+
+VALUE
+rb_cstr_to_rat(const char *s, int strict) /* for complex's internal */
+{
+ VALUE num;
+
+ num = parse_rat(s, s + strlen(s), strict, TRUE);
+
+ if (RB_FLOAT_TYPE_P(num) && !FLOAT_ZERO_P(num))
+ rb_raise(rb_eFloatDomainError, "Infinity");
+ return num;
+}
+
+static VALUE
+to_rational(VALUE val)
+{
+ return rb_convert_type_with_id(val, T_RATIONAL, "Rational", idTo_r);
+}
+
+static VALUE
+nurat_convert(VALUE klass, VALUE numv, VALUE denv, int raise)
+{
+ VALUE a1 = numv, a2 = denv;
+ int state;
+
+ RUBY_ASSERT(!UNDEF_P(a1));
+
+ if (NIL_P(a1) || NIL_P(a2)) {
+ if (!raise) return Qnil;
+ rb_raise(rb_eTypeError, "can't convert nil into Rational");
+ }
+
+ if (RB_TYPE_P(a1, T_COMPLEX)) {
+ if (k_exact_zero_p(RCOMPLEX(a1)->imag))
+ a1 = RCOMPLEX(a1)->real;
+ }
+
+ if (RB_TYPE_P(a2, T_COMPLEX)) {
+ if (k_exact_zero_p(RCOMPLEX(a2)->imag))
+ a2 = RCOMPLEX(a2)->real;
+ }
+
+ if (RB_INTEGER_TYPE_P(a1)) {
+ // nothing to do
+ }
+ else if (RB_FLOAT_TYPE_P(a1)) {
+ a1 = float_to_r(a1);
+ }
+ else if (RB_TYPE_P(a1, T_RATIONAL)) {
+ // nothing to do
+ }
+ else if (RB_TYPE_P(a1, T_STRING)) {
+ a1 = string_to_r_strict(a1, raise);
+ if (!raise && NIL_P(a1)) return Qnil;
+ }
+ else if (!rb_respond_to(a1, idTo_r)) {
+ VALUE tmp = rb_protect(rb_check_to_int, a1, NULL);
+ rb_set_errinfo(Qnil);
+ if (!NIL_P(tmp)) {
+ a1 = tmp;
+ }
+ }
+
+ if (RB_INTEGER_TYPE_P(a2)) {
+ // nothing to do
+ }
+ else if (RB_FLOAT_TYPE_P(a2)) {
+ a2 = float_to_r(a2);
+ }
+ else if (RB_TYPE_P(a2, T_RATIONAL)) {
+ // nothing to do
+ }
+ else if (RB_TYPE_P(a2, T_STRING)) {
+ a2 = string_to_r_strict(a2, raise);
+ if (!raise && NIL_P(a2)) return Qnil;
+ }
+ else if (!UNDEF_P(a2) && !rb_respond_to(a2, idTo_r)) {
+ VALUE tmp = rb_protect(rb_check_to_int, a2, NULL);
+ rb_set_errinfo(Qnil);
+ if (!NIL_P(tmp)) {
+ a2 = tmp;
+ }
+ }
+
+ if (RB_TYPE_P(a1, T_RATIONAL)) {
+ if (UNDEF_P(a2) || (k_exact_one_p(a2)))
+ return a1;
+ }
+
+ if (UNDEF_P(a2)) {
+ if (!RB_INTEGER_TYPE_P(a1)) {
+ if (!raise) {
+ VALUE result = rb_protect(to_rational, a1, NULL);
+ rb_set_errinfo(Qnil);
+ return result;
+ }
+ return to_rational(a1);
+ }
+ }
+ else {
+ if (!k_numeric_p(a1)) {
+ if (!raise) {
+ a1 = rb_protect(to_rational, a1, &state);
+ if (state) {
+ rb_set_errinfo(Qnil);
+ return Qnil;
+ }
+ }
+ else {
+ a1 = rb_check_convert_type_with_id(a1, T_RATIONAL, "Rational", idTo_r);
+ }
+ }
+ if (!k_numeric_p(a2)) {
+ if (!raise) {
+ a2 = rb_protect(to_rational, a2, &state);
+ if (state) {
+ rb_set_errinfo(Qnil);
+ return Qnil;
+ }
+ }
+ else {
+ a2 = rb_check_convert_type_with_id(a2, T_RATIONAL, "Rational", idTo_r);
+ }
+ }
+ if ((k_numeric_p(a1) && k_numeric_p(a2)) &&
+ (!f_integer_p(a1) || !f_integer_p(a2))) {
+ VALUE tmp = rb_protect(to_rational, a1, &state);
+ if (!state) {
+ a1 = tmp;
+ }
+ else {
+ rb_set_errinfo(Qnil);
+ }
+ return f_div(a1, a2);
+ }
+ }
+
+ a1 = nurat_int_value(a1);
+
+ if (UNDEF_P(a2)) {
+ a2 = ONE;
+ }
+ else if (!k_integer_p(a2) && !raise) {
+ return Qnil;
+ }
+ else {
+ a2 = nurat_int_value(a2);
+ }
+
+
+ return nurat_s_canonicalize_internal(klass, a1, a2);
+}
+
+static VALUE
+nurat_s_convert(int argc, VALUE *argv, VALUE klass)
+{
+ VALUE a1, a2;
+
+ if (rb_scan_args(argc, argv, "11", &a1, &a2) == 1) {
+ a2 = Qundef;
+ }
+
+ return nurat_convert(klass, a1, a2, TRUE);
+}
+
+/*
+ * A rational number can be represented as a pair of integer numbers:
+ * a/b (b>0), where a is the numerator and b is the denominator.
+ * Integer a equals rational a/1 mathematically.
+ *
+ * You can create a \Rational object explicitly with:
+ *
+ * - A {rational literal}[rdoc-ref:syntax/literals.rdoc@Rational+Literals].
+ *
+ * You can convert certain objects to Rationals with:
+ *
+ * - Method #Rational.
+ *
+ * Examples
+ *
+ * Rational(1) #=> (1/1)
+ * Rational(2, 3) #=> (2/3)
+ * Rational(4, -6) #=> (-2/3) # Reduced.
+ * 3.to_r #=> (3/1)
+ * 2/3r #=> (2/3)
+ *
+ * You can also create rational objects from floating-point numbers or
+ * strings.
+ *
+ * Rational(0.3) #=> (5404319552844595/18014398509481984)
+ * Rational('0.3') #=> (3/10)
+ * Rational('2/3') #=> (2/3)
+ *
+ * 0.3.to_r #=> (5404319552844595/18014398509481984)
+ * '0.3'.to_r #=> (3/10)
+ * '2/3'.to_r #=> (2/3)
+ * 0.3.rationalize #=> (3/10)
+ *
+ * A rational object is an exact number, which helps you to write
+ * programs without any rounding errors.
+ *
+ * 10.times.inject(0) {|t| t + 0.1 } #=> 0.9999999999999999
+ * 10.times.inject(0) {|t| t + Rational('0.1') } #=> (1/1)
+ *
+ * However, when an expression includes an inexact component (numerical value
+ * or operation), it will produce an inexact result.
+ *
+ * Rational(10) / 3 #=> (10/3)
+ * Rational(10) / 3.0 #=> 3.3333333333333335
+ *
+ * Rational(-8) ** Rational(1, 3)
+ * #=> (1.0000000000000002+1.7320508075688772i)
+ */
+void
+Init_Rational(void)
+{
+ VALUE compat;
+ id_abs = rb_intern_const("abs");
+ id_integer_p = rb_intern_const("integer?");
+ id_i_num = rb_intern_const("@numerator");
+ id_i_den = rb_intern_const("@denominator");
+
+ rb_cRational = rb_define_class("Rational", rb_cNumeric);
+
+ rb_define_alloc_func(rb_cRational, nurat_s_alloc);
+ rb_undef_method(CLASS_OF(rb_cRational), "allocate");
+
+ rb_undef_method(CLASS_OF(rb_cRational), "new");
+
+ rb_define_global_function("Rational", nurat_f_rational, -1);
+
+ rb_define_method(rb_cRational, "numerator", nurat_numerator, 0);
+ rb_define_method(rb_cRational, "denominator", nurat_denominator, 0);
+
+ rb_define_method(rb_cRational, "-@", rb_rational_uminus, 0);
+ rb_define_method(rb_cRational, "+", rb_rational_plus, 1);
+ rb_define_method(rb_cRational, "-", rb_rational_minus, 1);
+ rb_define_method(rb_cRational, "*", rb_rational_mul, 1);
+ rb_define_method(rb_cRational, "/", rb_rational_div, 1);
+ rb_define_method(rb_cRational, "quo", rb_rational_div, 1);
+ rb_define_method(rb_cRational, "fdiv", nurat_fdiv, 1);
+ rb_define_method(rb_cRational, "**", nurat_expt, 1);
+
+ rb_define_method(rb_cRational, "<=>", rb_rational_cmp, 1);
+ rb_define_method(rb_cRational, "==", nurat_eqeq_p, 1);
+ rb_define_method(rb_cRational, "coerce", nurat_coerce, 1);
+
+ rb_define_method(rb_cRational, "positive?", nurat_positive_p, 0);
+ rb_define_method(rb_cRational, "negative?", nurat_negative_p, 0);
+ rb_define_method(rb_cRational, "abs", rb_rational_abs, 0);
+ rb_define_method(rb_cRational, "magnitude", rb_rational_abs, 0);
+
+ rb_define_method(rb_cRational, "floor", nurat_floor_n, -1);
+ rb_define_method(rb_cRational, "ceil", nurat_ceil_n, -1);
+ rb_define_method(rb_cRational, "truncate", nurat_truncate_n, -1);
+ rb_define_method(rb_cRational, "round", nurat_round_n, -1);
+
+ rb_define_method(rb_cRational, "to_i", nurat_truncate, 0);
+ rb_define_method(rb_cRational, "to_f", nurat_to_f, 0);
+ rb_define_method(rb_cRational, "to_r", nurat_to_r, 0);
+ rb_define_method(rb_cRational, "rationalize", nurat_rationalize, -1);
+
+ rb_define_method(rb_cRational, "hash", nurat_hash, 0);
+
+ rb_define_method(rb_cRational, "to_s", nurat_to_s, 0);
+ rb_define_method(rb_cRational, "inspect", nurat_inspect, 0);
+
+ rb_define_private_method(rb_cRational, "marshal_dump", nurat_marshal_dump, 0);
+ /* :nodoc: */
+ compat = rb_define_class_under(rb_cRational, "compatible", rb_cObject);
+ rb_define_private_method(compat, "marshal_load", nurat_marshal_load, 1);
+ rb_marshal_define_compat(rb_cRational, compat, nurat_dumper, nurat_loader);
+
+ rb_define_method(rb_cInteger, "gcd", rb_gcd, 1);
+ rb_define_method(rb_cInteger, "lcm", rb_lcm, 1);
+ rb_define_method(rb_cInteger, "gcdlcm", rb_gcdlcm, 1);
+
+ rb_define_method(rb_cNumeric, "numerator", numeric_numerator, 0);
+ rb_define_method(rb_cNumeric, "denominator", numeric_denominator, 0);
+ rb_define_method(rb_cNumeric, "quo", rb_numeric_quo, 1);
+
+ rb_define_method(rb_cFloat, "numerator", rb_float_numerator, 0);
+ rb_define_method(rb_cFloat, "denominator", rb_float_denominator, 0);
+
+ rb_define_method(rb_cInteger, "to_r", integer_to_r, 0);
+ rb_define_method(rb_cInteger, "rationalize", integer_rationalize, -1);
+ rb_define_method(rb_cFloat, "to_r", float_to_r, 0);
+ rb_define_method(rb_cFloat, "rationalize", float_rationalize, -1);
+
+ rb_define_method(rb_cString, "to_r", string_to_r, 0);
+
+ rb_define_private_method(CLASS_OF(rb_cRational), "convert", nurat_s_convert, -1);
+
+ rb_provide("rational.so"); /* for backward compatibility */
+}
generated by cgit v1.2.3 (git 2.25.1) at 2026-01-23 09:06:45 +0000