/* 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.h" #include "internal.h" #include #include #ifdef HAVE_IEEEFP_H #include #endif #define NDEBUG #include #if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H) #define USE_GMP #include #endif #define ZERO INT2FIX(0) #define ONE INT2FIX(1) #define TWO INT2FIX(2) #define GMP_GCD_DIGITS 1 VALUE rb_cRational; static ID id_abs, id_cmp, id_convert, id_eqeq_p, id_expt, id_fdiv, id_idiv, id_integer_p, id_negate, id_to_f, id_to_i, id_truncate, id_i_num, id_i_den; #define f_boolcast(x) ((x) ? Qtrue : Qfalse) #define f_inspect rb_inspect #define f_to_s rb_obj_as_string #define binop(n,op) \ inline static VALUE \ f_##n(VALUE x, VALUE y)\ {\ return rb_funcall(x, (op), 1, y);\ } #define fun1(n) \ inline static VALUE \ f_##n(VALUE x)\ {\ return rb_funcall(x, id_##n, 0);\ } #define fun2(n) \ inline static VALUE \ f_##n(VALUE x, VALUE y)\ {\ return rb_funcall(x, id_##n, 1, y);\ } inline static VALUE f_add(VALUE x, VALUE y) { if (FIXNUM_P(y) && FIX2LONG(y) == 0) return x; else if (FIXNUM_P(x) && FIX2LONG(x) == 0) return y; return rb_funcall(x, '+', 1, y); } inline static VALUE f_cmp(VALUE x, VALUE y) { if (FIXNUM_P(x) && FIXNUM_P(y)) { long c = FIX2LONG(x) - FIX2LONG(y); if (c > 0) c = 1; else if (c < 0) c = -1; return INT2FIX(c); } return rb_funcall(x, id_cmp, 1, y); } inline static VALUE f_div(VALUE x, VALUE y) { if (FIXNUM_P(y) && FIX2LONG(y) == 1) return x; return rb_funcall(x, '/', 1, y); } inline static VALUE f_lt_p(VALUE x, VALUE y) { if (FIXNUM_P(x) && FIXNUM_P(y)) return f_boolcast(FIX2LONG(x) < FIX2LONG(y)); return rb_funcall(x, '<', 1, y); } binop(mod, '%') inline static VALUE f_mul(VALUE x, VALUE y) { if (FIXNUM_P(y)) { long iy = FIX2LONG(y); if (iy == 0) { if (FIXNUM_P(x) || RB_TYPE_P(x, T_BIGNUM)) return ZERO; } else if (iy == 1) return x; } else if (FIXNUM_P(x)) { long ix = FIX2LONG(x); if (ix == 0) { if (FIXNUM_P(y) || RB_TYPE_P(y, T_BIGNUM)) return ZERO; } else if (ix == 1) return y; } return rb_funcall(x, '*', 1, y); } inline static VALUE f_sub(VALUE x, VALUE y) { if (FIXNUM_P(y) && FIX2LONG(y) == 0) return x; return rb_funcall(x, '-', 1, y); } fun1(abs) fun1(integer_p) fun1(negate) 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 VALUE f_to_f(VALUE x) { if (RB_TYPE_P(x, T_STRING)) return DBL2NUM(rb_str_to_dbl(x, 0)); return rb_funcall(x, id_to_f, 0); } inline static VALUE f_eqeq_p(VALUE x, VALUE y) { if (FIXNUM_P(x) && FIXNUM_P(y)) return f_boolcast(FIX2LONG(x) == FIX2LONG(y)); return rb_funcall(x, id_eqeq_p, 1, y); } fun2(expt) fun2(fdiv) fun2(idiv) #define f_expt10(x) f_expt(INT2FIX(10), x) inline static VALUE f_negative_p(VALUE x) { if (FIXNUM_P(x)) return f_boolcast(FIX2LONG(x) < 0); return rb_funcall(x, '<', 1, ZERO); } #define f_positive_p(x) (!f_negative_p(x)) inline static VALUE f_zero_p(VALUE x) { if (RB_TYPE_P(x, T_FIXNUM)) { return f_boolcast(FIX2LONG(x) == 0); } else if (RB_TYPE_P(x, T_BIGNUM)) { return Qfalse; } else if (RB_TYPE_P(x, T_RATIONAL)) { VALUE num = RRATIONAL(x)->num; return f_boolcast(FIXNUM_P(num) && FIX2LONG(num) == 0); } return rb_funcall(x, id_eqeq_p, 1, ZERO); } #define f_nonzero_p(x) (!f_zero_p(x)) inline static VALUE f_one_p(VALUE x) { if (RB_TYPE_P(x, T_FIXNUM)) { return f_boolcast(FIX2LONG(x) == 1); } else if (RB_TYPE_P(x, T_BIGNUM)) { return Qfalse; } else if (RB_TYPE_P(x, T_RATIONAL)) { VALUE num = RRATIONAL(x)->num; VALUE den = RRATIONAL(x)->den; return f_boolcast(FIXNUM_P(num) && FIX2LONG(num) == 1 && FIXNUM_P(den) && FIX2LONG(den) == 1); } return rb_funcall(x, id_eqeq_p, 1, ONE); } inline static VALUE f_minus_one_p(VALUE x) { if (RB_TYPE_P(x, T_FIXNUM)) { return f_boolcast(FIX2LONG(x) == -1); } else if (RB_TYPE_P(x, T_BIGNUM)) { return Qfalse; } else if (RB_TYPE_P(x, T_RATIONAL)) { VALUE num = RRATIONAL(x)->num; VALUE den = RRATIONAL(x)->den; return f_boolcast(FIXNUM_P(num) && FIX2LONG(num) == -1 && FIXNUM_P(den) && FIX2LONG(den) == 1); } return rb_funcall(x, id_eqeq_p, 1, INT2FIX(-1)); } inline static VALUE f_kind_of_p(VALUE x, VALUE c) { return rb_obj_is_kind_of(x, c); } inline static VALUE k_numeric_p(VALUE x) { return f_kind_of_p(x, rb_cNumeric); } inline static VALUE k_integer_p(VALUE x) { return f_kind_of_p(x, rb_cInteger); } inline static VALUE k_float_p(VALUE x) { return f_kind_of_p(x, rb_cFloat); } inline static VALUE k_rational_p(VALUE x) { return f_kind_of_p(x, rb_cRational); } #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)) #ifdef 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); 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); return rb_big_norm(z); } #endif #ifndef NDEBUG #define f_gcd f_gcd_orig #endif inline static long i_gcd(long x, long y) { if (x < 0) x = -x; if (y < 0) y = -y; if (x == 0) return y; if (y == 0) return x; while (x > 0) { long t = x; x = y % x; y = t; } return y; } 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 (f_negative_p(x)) x = f_negate(x); if (f_negative_p(y)) y = f_negate(y); if (f_zero_p(x)) return y; if (f_zero_p(y)) return x; for (;;) { if (FIXNUM_P(x)) { if (FIX2LONG(x) == 0) return y; if (FIXNUM_P(y)) return LONG2NUM(i_gcd(FIX2LONG(x), FIX2LONG(y))); } z = x; x = f_mod(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) { #ifdef USE_GMP if (RB_TYPE_P(x, T_BIGNUM) && RB_TYPE_P(y, T_BIGNUM)) { 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)) { assert(f_zero_p(f_mod(x, r))); assert(f_zero_p(f_mod(y, r))); } return r; } #endif inline static VALUE f_lcm(VALUE x, VALUE y) { if (f_zero_p(x) || f_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;\ dat = ((struct RRational *)(x)) #define get_dat2(x,y) \ struct RRational *adat, *bdat;\ adat = ((struct RRational *)(x));\ bdat = ((struct RRational *)(y)) #define RRATIONAL_SET_NUM(rat, n) RB_OBJ_WRITE((rat), &((struct RRational *)(rat))->num,(n)) #define RRATIONAL_SET_DEN(rat, d) RB_OBJ_WRITE((rat), &((struct RRational *)(rat))->den,(d)) 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)); RRATIONAL_SET_NUM(obj, num); RRATIONAL_SET_DEN(obj, den); return (VALUE)obj; } static VALUE nurat_s_alloc(VALUE klass) { return nurat_s_new_internal(klass, ZERO, ONE); } #define rb_raise_zerodiv() rb_raise(rb_eZeroDivError, "divided by 0") #if 0 static VALUE nurat_s_new_bang(int argc, VALUE *argv, VALUE klass) { VALUE num, den; switch (rb_scan_args(argc, argv, "11", &num, &den)) { case 1: if (!k_integer_p(num)) num = f_to_i(num); den = ONE; break; default: if (!k_integer_p(num)) num = f_to_i(num); if (!k_integer_p(den)) den = f_to_i(den); switch (FIX2INT(f_cmp(den, ZERO))) { case -1: num = f_negate(num); den = f_negate(den); break; case 0: rb_raise_zerodiv(); break; } break; } return nurat_s_new_internal(klass, num, den); } #endif inline static VALUE f_rational_new_bang1(VALUE klass, VALUE x) { return nurat_s_new_internal(klass, x, ONE); } #ifdef CANONICALIZATION_FOR_MATHN #define CANON #endif #ifdef CANON static int canonicalization = 0; RUBY_FUNC_EXPORTED void nurat_canonicalization(int f) { canonicalization = f; } #endif inline static void nurat_int_check(VALUE num) { if (!(RB_TYPE_P(num, T_FIXNUM) || RB_TYPE_P(num, T_BIGNUM))) { 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; } inline static VALUE nurat_s_canonicalize_internal(VALUE klass, VALUE num, VALUE den) { VALUE gcd; switch (FIX2INT(f_cmp(den, ZERO))) { case -1: num = f_negate(num); den = f_negate(den); break; case 0: rb_raise_zerodiv(); break; } gcd = f_gcd(num, den); num = f_idiv(num, gcd); den = f_idiv(den, gcd); #ifdef CANON if (f_one_p(den) && canonicalization) return num; #endif return nurat_s_new_internal(klass, num, den); } inline static VALUE nurat_s_canonicalize_internal_no_reduce(VALUE klass, VALUE num, VALUE den) { switch (FIX2INT(f_cmp(den, ZERO))) { case -1: num = f_negate(num); den = f_negate(den); break; case 0: rb_raise_zerodiv(); break; } #ifdef CANON if (f_one_p(den) && canonicalization) return num; #endif return nurat_s_new_internal(klass, num, den); } static VALUE nurat_s_new(int argc, VALUE *argv, VALUE klass) { VALUE num, den; switch (rb_scan_args(argc, argv, "11", &num, &den)) { case 1: num = nurat_int_value(num); den = ONE; break; default: num = nurat_int_value(num); den = nurat_int_value(den); break; } return nurat_s_canonicalize_internal(klass, num, den); } inline static VALUE f_rational_new2(VALUE klass, VALUE x, VALUE y) { assert(!k_rational_p(x)); 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) { assert(!k_rational_p(x)); assert(!k_rational_p(y)); return nurat_s_canonicalize_internal_no_reduce(klass, x, y); } /* * call-seq: * Rational(x[, y]) -> numeric * * Returns x/y; * * Rational(1, 2) #=> (1/2) * Rational('1/2') #=> (1/2) * Rational(nil) #=> TypeError * Rational(1, nil) #=> TypeError * * Syntax of 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 String#to_r. */ static VALUE nurat_f_rational(int argc, VALUE *argv, VALUE klass) { return rb_funcall2(rb_cRational, id_convert, argc, argv); } /* * 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 * rat.numerator.gcd(rat.denominator) #=> 1 */ static VALUE nurat_denominator(VALUE self) { get_dat1(self); return 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); 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 = f_add(a, b); else c = f_sub(a, b); b = f_idiv(aden, g); g = f_gcd(c, g); num = f_idiv(c, g); a = f_idiv(bden, g); den = f_mul(a, b); } else { VALUE g = f_gcd(aden, bden); VALUE a = f_mul(anum, f_idiv(bden, g)); VALUE b = f_mul(bnum, f_idiv(aden, g)); VALUE c; if (k == '+') c = f_add(a, b); else c = f_sub(a, b); b = f_idiv(aden, g); g = f_gcd(c, g); num = f_idiv(c, g); a = f_idiv(bden, g); den = f_mul(a, b); } return f_rational_new_no_reduce2(CLASS_OF(self), num, den); } /* * call-seq: * rat + numeric -> numeric * * Performs addition. * * Rational(2, 3) + Rational(2, 3) #=> (4/3) * Rational(900) + Rational(1) #=> (900/1) * Rational(-2, 9) + Rational(-9, 2) #=> (-85/18) * Rational(9, 8) + 4 #=> (41/8) * Rational(20, 9) + 9.8 #=> 12.022222222222222 */ static VALUE nurat_add(VALUE self, VALUE other) { if (RB_TYPE_P(other, T_FIXNUM) || RB_TYPE_P(other, T_BIGNUM)) { { get_dat1(self); return f_addsub(self, dat->num, dat->den, other, ONE, '+'); } } else if (RB_TYPE_P(other, T_FLOAT)) { return f_add(f_to_f(self), 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: * rat - numeric -> numeric * * Performs subtraction. * * 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 */ static VALUE nurat_sub(VALUE self, VALUE other) { if (RB_TYPE_P(other, T_FIXNUM) || RB_TYPE_P(other, T_BIGNUM)) { { get_dat1(self); return f_addsub(self, dat->num, dat->den, other, ONE, '-'); } } else if (RB_TYPE_P(other, T_FLOAT)) { return f_sub(f_to_f(self), 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; if (k == '/') { VALUE t; if (f_negative_p(bnum)) { anum = f_negate(anum); bnum = f_negate(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 = f_mul(f_idiv(anum, g1), f_idiv(bnum, g2)); den = f_mul(f_idiv(aden, g2), f_idiv(bden, g1)); } return f_rational_new_no_reduce2(CLASS_OF(self), num, den); } /* * call-seq: * rat * numeric -> numeric * * Performs multiplication. * * Rational(2, 3) * Rational(2, 3) #=> (4/9) * Rational(900) * Rational(1) #=> (900/1) * Rational(-2, 9) * Rational(-9, 2) #=> (1/1) * Rational(9, 8) * 4 #=> (9/2) * Rational(20, 9) * 9.8 #=> 21.77777777777778 */ static VALUE nurat_mul(VALUE self, VALUE other) { if (RB_TYPE_P(other, T_FIXNUM) || RB_TYPE_P(other, T_BIGNUM)) { { get_dat1(self); return f_muldiv(self, dat->num, dat->den, other, ONE, '*'); } } else if (RB_TYPE_P(other, T_FLOAT)) { return f_mul(f_to_f(self), 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: * rat / numeric -> numeric * rat.quo(numeric) -> numeric * * Performs division. * * 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 */ static VALUE nurat_div(VALUE self, VALUE other) { if (RB_TYPE_P(other, T_FIXNUM) || RB_TYPE_P(other, T_BIGNUM)) { if (f_zero_p(other)) rb_raise_zerodiv(); { get_dat1(self); return f_muldiv(self, dat->num, dat->den, other, ONE, '/'); } } else if (RB_TYPE_P(other, T_FLOAT)) return rb_funcall(f_to_f(self), '/', 1, other); else if (RB_TYPE_P(other, T_RATIONAL)) { if (f_zero_p(other)) rb_raise_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) { if (f_zero_p(other)) return f_div(self, f_to_f(other)); return f_to_f(f_div(self, other)); } inline static VALUE f_odd_p(VALUE integer) { if (rb_funcall(integer, '%', 1, INT2FIX(2)) != INT2FIX(0)) { return Qtrue; } return Qfalse; } /* * call-seq: * rat ** numeric -> numeric * * Performs exponentiation. * * Rational(2) ** Rational(3) #=> (8/1) * Rational(10) ** -2 #=> (1/100) * Rational(10) ** -2.0 #=> 0.01 * Rational(-4) ** Rational(1,2) #=> (1.2246063538223773e-16+2.0i) * Rational(1, 2) ** 0 #=> (1/1) * Rational(1, 2) ** 0.0 #=> 1.0 */ static VALUE nurat_expt(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) && k_integer_p(other)) { return f_rational_new_bang1(CLASS_OF(self), INT2FIX(f_odd_p(other) ? -1 : 1)); } else if (f_zero_p(dat->num)) { if (FIX2INT(f_cmp(other, ZERO)) == -1) { rb_raise_zerodiv(); } else { return f_rational_new_bang1(CLASS_OF(self), ZERO); } } } } /* General case */ if (RB_TYPE_P(other, T_FIXNUM)) { { VALUE num, den; get_dat1(self); switch (FIX2INT(f_cmp(other, ZERO))) { case 1: num = f_expt(dat->num, other); den = f_expt(dat->den, other); break; case -1: num = f_expt(dat->den, f_negate(other)); den = f_expt(dat->num, f_negate(other)); break; default: num = ONE; den = ONE; break; } return f_rational_new2(CLASS_OF(self), num, den); } } else if (RB_TYPE_P(other, T_BIGNUM)) { rb_warn("in a**b, b may be too big"); return f_expt(f_to_f(self), other); } else if (RB_TYPE_P(other, T_FLOAT) || RB_TYPE_P(other, T_RATIONAL)) { return f_expt(f_to_f(self), other); } else { return rb_num_coerce_bin(self, other, id_expt); } } /* * call-seq: * rational <=> numeric -> -1, 0, +1 or nil * * Performs comparison and returns -1, 0, or +1. * * +nil+ is returned if the two values are incomparable. * * Rational(2, 3) <=> Rational(2, 3) #=> 0 * Rational(5) <=> 5 #=> 0 * Rational(2,3) <=> Rational(1,3) #=> 1 * Rational(1,3) <=> 1 #=> -1 * Rational(1,3) <=> 0.3 #=> 1 */ static VALUE nurat_cmp(VALUE self, VALUE other) { if (RB_TYPE_P(other, T_FIXNUM) || RB_TYPE_P(other, T_BIGNUM)) { { get_dat1(self); if (FIXNUM_P(dat->den) && FIX2LONG(dat->den) == 1) return f_cmp(dat->num, other); /* c14n */ return f_cmp(self, f_rational_new_bang1(CLASS_OF(self), other)); } } else if (RB_TYPE_P(other, T_FLOAT)) { return f_cmp(f_to_f(self), other); } else if (RB_TYPE_P(other, 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 = f_mul(adat->num, bdat->den); num2 = f_mul(bdat->num, adat->den); } return f_cmp(f_sub(num1, num2), ZERO); } } else { return rb_num_coerce_cmp(self, other, id_cmp); } } /* * call-seq: * rat == object -> true or false * * Returns true if rat equals object numerically. * * 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_TYPE_P(other, T_FIXNUM) || RB_TYPE_P(other, T_BIGNUM)) { { get_dat1(self); if (f_zero_p(dat->num) && f_zero_p(other)) return Qtrue; if (!FIXNUM_P(dat->den)) return Qfalse; if (FIX2LONG(dat->den) != 1) return Qfalse; if (f_eqeq_p(dat->num, other)) return Qtrue; return Qfalse; } } else if (RB_TYPE_P(other, T_FLOAT)) { return f_eqeq_p(f_to_f(self), other); } else if (RB_TYPE_P(other, T_RATIONAL)) { { get_dat2(self, other); if (f_zero_p(adat->num) && f_zero_p(bdat->num)) return Qtrue; return f_boolcast(f_eqeq_p(adat->num, bdat->num) && f_eqeq_p(adat->den, bdat->den)); } } else { return f_eqeq_p(other, self); } } /* :nodoc: */ static VALUE nurat_coerce(VALUE self, VALUE other) { if (RB_TYPE_P(other, T_FIXNUM) || RB_TYPE_P(other, T_BIGNUM)) { return rb_assoc_new(f_rational_new_bang1(CLASS_OF(self), other), self); } else if (RB_TYPE_P(other, T_FLOAT)) { return rb_assoc_new(other, f_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(f_rational_new_bang1 (CLASS_OF(self), RCOMPLEX(other)->real), self); else return rb_assoc_new(other, rb_Complex(self, INT2FIX(0))); } rb_raise(rb_eTypeError, "%s can't be coerced into %s", rb_obj_classname(other), rb_obj_classname(self)); return Qnil; } #if 0 /* :nodoc: */ static VALUE nurat_idiv(VALUE self, VALUE other) { return f_idiv(self, other); } /* :nodoc: */ static VALUE nurat_quot(VALUE self, VALUE other) { return f_truncate(f_div(self, other)); } /* :nodoc: */ static VALUE nurat_quotrem(VALUE self, VALUE other) { VALUE val = f_truncate(f_div(self, other)); return rb_assoc_new(val, f_sub(self, f_mul(other, val))); } #endif #if 0 /* :nodoc: */ static VALUE nurat_true(VALUE self) { return Qtrue; } #endif static VALUE nurat_floor(VALUE self) { get_dat1(self); return f_idiv(dat->num, dat->den); } static VALUE nurat_ceil(VALUE self) { get_dat1(self); return f_negate(f_idiv(f_negate(dat->num), dat->den)); } /* * call-seq: * rat.to_i -> integer * * Returns the truncated value as an integer. * * Equivalent to * rat.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(-30,2).to_i #=> -15 */ static VALUE nurat_truncate(VALUE self) { get_dat1(self); if (f_negative_p(dat->num)) return f_negate(f_idiv(f_negate(dat->num), dat->den)); return f_idiv(dat->num, dat->den); } static VALUE nurat_round(VALUE self) { VALUE num, den, neg; get_dat1(self); num = dat->num; den = dat->den; neg = f_negative_p(num); if (neg) num = f_negate(num); num = f_add(f_mul(num, TWO), den); den = f_mul(den, TWO); num = f_idiv(num, den); if (neg) num = f_negate(num); return num; } static VALUE f_round_common(int argc, VALUE *argv, VALUE self, VALUE (*func)(VALUE)) { VALUE n, b, s; if (argc == 0) return (*func)(self); rb_scan_args(argc, argv, "01", &n); if (!k_integer_p(n)) rb_raise(rb_eTypeError, "not an integer"); b = f_expt10(n); s = f_mul(self, b); if (k_float_p(s)) { if (f_lt_p(n, ZERO)) return ZERO; return self; } if (!k_rational_p(s)) { s = f_rational_new_bang1(CLASS_OF(self), s); } s = (*func)(s); s = f_div(f_rational_new_bang1(CLASS_OF(self), s), b); if (f_lt_p(n, ONE)) s = f_to_i(s); return s; } /* * call-seq: * rat.floor -> integer * rat.floor(precision=0) -> rational * * Returns the truncated value (toward negative infinity). * * Rational(3).floor #=> 3 * Rational(2, 3).floor #=> 0 * Rational(-3, 2).floor #=> -1 * * decimal - 1 2 3 . 4 5 6 * ^ ^ ^ ^ ^ ^ * precision -3 -2 -1 0 +1 +2 * * '%f' % Rational('-123.456').floor(+1) #=> "-123.500000" * '%f' % Rational('-123.456').floor(-1) #=> "-130.000000" */ static VALUE nurat_floor_n(int argc, VALUE *argv, VALUE self) { return f_round_common(argc, argv, self, nurat_floor); } /* * call-seq: * rat.ceil -> integer * rat.ceil(precision=0) -> rational * * Returns the truncated value (toward positive infinity). * * 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 * * '%f' % Rational('-123.456').ceil(+1) #=> "-123.400000" * '%f' % Rational('-123.456').ceil(-1) #=> "-120.000000" */ static VALUE nurat_ceil_n(int argc, VALUE *argv, VALUE self) { return f_round_common(argc, argv, self, nurat_ceil); } /* * call-seq: * rat.truncate -> integer * rat.truncate(precision=0) -> rational * * Returns the truncated value (toward zero). * * 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 * * '%f' % Rational('-123.456').truncate(+1) #=> "-123.400000" * '%f' % Rational('-123.456').truncate(-1) #=> "-120.000000" */ static VALUE nurat_truncate_n(int argc, VALUE *argv, VALUE self) { return f_round_common(argc, argv, self, nurat_truncate); } /* * call-seq: * rat.round -> integer * rat.round(precision=0) -> rational * * Returns the truncated value (toward the nearest integer; * 0.5 => 1; -0.5 => -1). * * 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 * * '%f' % Rational('-123.456').round(+1) #=> "-123.500000" * '%f' % Rational('-123.456').round(-1) #=> "-120.000000" */ static VALUE nurat_round_n(int argc, VALUE *argv, VALUE self) { return f_round_common(argc, argv, self, nurat_round); } /* * call-seq: * rat.to_f -> float * * Return 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) { get_dat1(self); return f_fdiv(dat->num, dat->den); } /* * 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") #define f_ceil(x) rb_funcall((x), id_ceil, 0) #define id_quo rb_intern("quo") #define f_quo(x,y) rb_funcall((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; if (argc == 0) return self; if (f_negative_p(self)) return f_negate(nurat_rationalize(argc, argv, f_abs(self))); rb_scan_args(argc, argv, "01", &e); e = f_abs(e); a = f_sub(self, e); b = f_add(self, e); if (f_eqeq_p(a, b)) return self; nurat_rationalize_internal(a, b, &p, &q); return f_rational_new2(CLASS_OF(self), p, q); } /* :nodoc: */ static VALUE nurat_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 LONG2FIX(v); } 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) { get_dat1(self); RRATIONAL_SET_NUM(dat, rb_ivar_get(a, id_i_num)); RRATIONAL_SET_DEN(dat, rb_ivar_get(a, id_i_den)); 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) { rb_check_frozen(self); rb_check_trusted(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)); if (f_zero_p(RARRAY_AREF(a, 1))) rb_raise_zerodiv(); rb_ivar_set(self, id_i_num, RARRAY_AREF(a, 0)); rb_ivar_set(self, id_i_den, RARRAY_AREF(a, 1)); return self; } /* --- */ VALUE rb_rational_reciprocal(VALUE x) { get_dat1(x); return f_rational_new_no_reduce2(CLASS_OF(x), dat->den, dat->num); } /* * call-seq: * int.gcd(int2) -> integer * * Returns the greatest common divisor (always positive). 0.gcd(x) * and x.gcd(0) return abs(x). * * 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(int2) -> integer * * Returns the least common multiple (always positive). 0.lcm(x) and * x.lcm(0) return zero. * * 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(int2) -> array * * Returns an array; [int.gcd(int2), int.lcm(int2)]. * * 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) { 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); } static VALUE nurat_s_convert(int argc, VALUE *argv, VALUE klass); 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 rb_intern("to_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 most exact division (rational for integers, float for floats). */ static VALUE numeric_quo(VALUE x, VALUE y) { if (RB_TYPE_P(y, T_FLOAT)) { return f_fdiv(x, y); } #ifdef CANON if (canonicalization) { x = rb_rational_raw1(x); } else #endif { x = rb_convert_type(x, T_RATIONAL, "Rational", "to_r"); } return rb_funcall(x, '/', 1, y); } /* * call-seq: * int.numerator -> self * * Returns self. */ static VALUE integer_numerator(VALUE self) { return self; } /* * call-seq: * int.denominator -> 1 * * Returns 1. */ static VALUE integer_denominator(VALUE self) { return INT2FIX(1); } /* * 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 */ static VALUE float_numerator(VALUE self) { double d = RFLOAT_VALUE(self); if (isinf(d) || isnan(d)) return self; return rb_call_super(0, 0); } /* * call-seq: * flo.denominator -> integer * * Returns the denominator (always positive). The result is machine * dependent. * * See numerator. */ static VALUE float_denominator(VALUE self) { double d = RFLOAT_VALUE(self); if (isinf(d) || isnan(d)) return INT2FIX(1); return rb_call_super(0, 0); } /* * call-seq: * nil.to_r -> (0/1) * * Returns zero as a rational. */ static VALUE nilclass_to_r(VALUE self) { return rb_rational_new1(INT2FIX(0)); } /* * call-seq: * nil.rationalize([eps]) -> (0/1) * * Returns zero as a rational. The optional argument eps is always * ignored. */ static VALUE nilclass_rationalize(int argc, VALUE *argv, VALUE self) { rb_scan_args(argc, argv, "01", NULL); return nilclass_to_r(self); } /* * 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_scan_args(argc, argv, "01", NULL); return integer_to_r(self); } static void float_decode_internal(VALUE self, VALUE *rf, VALUE *rn) { double f; int n; f = frexp(RFLOAT_VALUE(self), &n); f = ldexp(f, DBL_MANT_DIG); n -= DBL_MANT_DIG; *rf = rb_dbl2big(f); *rn = INT2FIX(n); } #if 0 static VALUE float_decode(VALUE self) { VALUE f, n; float_decode_internal(self, &f, &n); return rb_assoc_new(f, n); } #endif #define id_lshift rb_intern("<<") #define f_lshift(x,n) rb_funcall((x), id_lshift, 1, (n)) /* * call-seq: * flt.to_r -> rational * * Returns the value as a rational. * * 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. * * 2.0.to_r #=> (2/1) * 2.5.to_r #=> (5/2) * -0.75.to_r #=> (-3/4) * 0.0.to_r #=> (0/1) * * See rationalize. */ static VALUE float_to_r(VALUE self) { VALUE f, n; float_decode_internal(self, &f, &n); #if FLT_RADIX == 2 { long ln = FIX2LONG(n); if (ln == 0) return f_to_r(f); if (ln > 0) return f_to_r(f_lshift(f, n)); ln = -ln; return rb_rational_new2(f, f_lshift(ONE, INT2FIX(ln))); } #else return f_to_r(f_mul(f, f_expt(INT2FIX(FLT_RADIX), n))); #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 f_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, n, p, q; float_decode_internal(flt, &f, &n); if (f_zero_p(f) || f_positive_p(n)) return rb_rational_new1(f_lshift(f, n)); #if FLT_RADIX == 2 { VALUE two_times_f, den; two_times_f = f_mul(TWO, f); den = f_lshift(ONE, f_sub(ONE, n)); a = rb_rational_new2(f_sub(two_times_f, ONE), den); b = rb_rational_new2(f_add(two_times_f, ONE), den); } #else { VALUE radix_times_f, den; radix_times_f = f_mul(INT2FIX(FLT_RADIX), f); den = f_expt(INT2FIX(FLT_RADIX), f_sub(ONE, n)); a = rb_rational_new2(f_sub(radix_times_f, INT2FIX(FLT_RADIX - 1)), den); b = rb_rational_new2(f_add(radix_times_f, INT2FIX(FLT_RADIX - 1)), den); } #endif if (f_eqeq_p(a, b)) return f_to_r(flt); 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 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 to_r. */ static VALUE float_rationalize(int argc, VALUE *argv, VALUE self) { VALUE e; if (f_negative_p(self)) return f_negate(float_rationalize(argc, argv, f_abs(self))); rb_scan_args(argc, argv, "01", &e); if (argc != 0) { return rb_flt_rationalize_with_prec(self, e); } else { return rb_flt_rationalize(self); } } #include inline static int issign(int c) { return (c == '-' || c == '+'); } static int read_sign(const char **s) { int sign = '?'; if (issign(**s)) { sign = **s; (*s)++; } return sign; } inline static int isdecimal(int c) { return isdigit((unsigned char)c); } static int read_digits(const char **s, int strict, VALUE *num, int *count) { char *b, *bb; int us = 1, ret = 1; VALUE tmp; if (!isdecimal(**s)) { *num = ZERO; return 0; } bb = b = ALLOCV_N(char, tmp, strlen(*s) + 1); while (isdecimal(**s) || **s == '_') { if (**s == '_') { if (strict) { if (us) { ret = 0; goto conv; } } us = 1; } else { if (count) (*count)++; *b++ = **s; us = 0; } (*s)++; } if (us) do { (*s)--; } while (**s == '_'); conv: *b = '\0'; *num = rb_cstr_to_inum(bb, 10, 0); ALLOCV_END(tmp); return ret; } inline static int islettere(int c) { return (c == 'e' || c == 'E'); } static int read_num(const char **s, int numsign, int strict, VALUE *num) { VALUE ip, fp, exp; *num = rb_rational_new2(ZERO, ONE); exp = Qnil; if (**s != '.') { if (!read_digits(s, strict, &ip, NULL)) return 0; *num = rb_rational_new2(ip, ONE); } if (**s == '.') { int count = 0; (*s)++; if (!read_digits(s, strict, &fp, &count)) return 0; { VALUE l = f_expt10(INT2NUM(count)); *num = f_mul(*num, l); *num = f_add(*num, fp); *num = f_div(*num, l); } } if (islettere(**s)) { int expsign; (*s)++; expsign = read_sign(s); if (!read_digits(s, strict, &exp, NULL)) return 0; if (expsign == '-') exp = f_negate(exp); } if (numsign == '-') *num = f_negate(*num); if (!NIL_P(exp)) { VALUE l = f_expt10(exp); *num = f_mul(*num, l); } return 1; } inline static int read_den(const char **s, int strict, VALUE *num) { if (!read_digits(s, strict, num, NULL)) return 0; return 1; } static int read_rat_nos(const char **s, int sign, int strict, VALUE *num) { VALUE den; if (!read_num(s, sign, strict, num)) return 0; if (**s == '/') { (*s)++; if (!read_den(s, strict, &den)) return 0; if (!(FIXNUM_P(den) && FIX2LONG(den) == 1)) *num = f_div(*num, den); } return 1; } static int read_rat(const char **s, int strict, VALUE *num) { int sign; sign = read_sign(s); if (!read_rat_nos(s, sign, strict, num)) return 0; return 1; } inline static void skip_ws(const char **s) { while (isspace((unsigned char)**s)) (*s)++; } static int parse_rat(const char *s, int strict, VALUE *num) { skip_ws(&s); if (!read_rat(&s, strict, num)) return 0; skip_ws(&s); if (strict) if (*s != '\0') return 0; return 1; } static VALUE string_to_r_strict(VALUE self) { char *s; VALUE num; rb_must_asciicompat(self); s = RSTRING_PTR(self); if (!s || memchr(s, '\0', RSTRING_LEN(self))) rb_raise(rb_eArgError, "string contains null byte"); if (s && s[RSTRING_LEN(self)]) { rb_str_modify(self); s = RSTRING_PTR(self); s[RSTRING_LEN(self)] = '\0'; } if (!s) s = (char *)""; if (!parse_rat(s, 1, &num)) { VALUE ins = f_inspect(self); rb_raise(rb_eArgError, "invalid value for convert(): %s", StringValuePtr(ins)); } if (RB_TYPE_P(num, T_FLOAT)) rb_raise(rb_eFloatDomainError, "Infinity"); return num; } /* * call-seq: * str.to_r -> rational * * Returns a rational which denotes the string form. The parser * ignores leading whitespaces and trailing garbage. Any digit * sequences can be separated by an underscore. Returns zero for null * or garbage string. * * NOTE: '0.3'.to_r isn't the same as 0.3.to_r. The former is * equivalent to '3/10'.to_r, but the latter isn't so. * * ' 2 '.to_r #=> (2/1) * '300/2'.to_r #=> (150/1) * '-9.2'.to_r #=> (-46/5) * '-9.2e2'.to_r #=> (-920/1) * '1_234_567'.to_r #=> (1234567/1) * '21 june 09'.to_r #=> (21/1) * '21/06/09'.to_r #=> (7/2) * 'bwv 1079'.to_r #=> (0/1) * * See Kernel.Rational. */ static VALUE string_to_r(VALUE self) { char *s; VALUE num; rb_must_asciicompat(self); s = RSTRING_PTR(self); if (s && s[RSTRING_LEN(self)]) { rb_str_modify(self); s = RSTRING_PTR(self); s[RSTRING_LEN(self)] = '\0'; } if (!s) s = (char *)""; (void)parse_rat(s, 0, &num); if (RB_TYPE_P(num, T_FLOAT)) rb_raise(rb_eFloatDomainError, "Infinity"); return num; } VALUE rb_cstr_to_rat(const char *s, int strict) /* for complex's internal */ { VALUE num; (void)parse_rat(s, strict, &num); if (RB_TYPE_P(num, T_FLOAT)) rb_raise(rb_eFloatDomainError, "Infinity"); return num; } static VALUE nurat_s_convert(int argc, VALUE *argv, VALUE klass) { VALUE a1, a2, backref; rb_scan_args(argc, argv, "11", &a1, &a2); if (NIL_P(a1) || (argc == 2 && NIL_P(a2))) 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; } backref = rb_backref_get(); rb_match_busy(backref); if (RB_TYPE_P(a1, T_FLOAT)) { a1 = f_to_r(a1); } else if (RB_TYPE_P(a1, T_STRING)) { a1 = string_to_r_strict(a1); } if (RB_TYPE_P(a2, T_FLOAT)) { a2 = f_to_r(a2); } else if (RB_TYPE_P(a2, T_STRING)) { a2 = string_to_r_strict(a2); } rb_backref_set(backref); if (RB_TYPE_P(a1, T_RATIONAL)) { if (argc == 1 || (k_exact_one_p(a2))) return a1; } if (argc == 1) { if (!(k_numeric_p(a1) && k_integer_p(a1))) return rb_convert_type(a1, T_RATIONAL, "Rational", "to_r"); } else { if ((k_numeric_p(a1) && k_numeric_p(a2)) && (!f_integer_p(a1) || !f_integer_p(a2))) return f_div(a1, a2); } { VALUE argv2[2]; argv2[0] = a1; argv2[1] = a2; return nurat_s_new(argc, argv2, klass); } } /* * A rational number can be represented as a paired integer number; * a/b (b>0). Where a is numerator and b is denominator. Integer a * equals rational a/1 mathematically. * * In ruby, you can create rational object with Rational, to_r or * rationalize method. The return values will be irreducible. * * Rational(1) #=> (1/1) * Rational(2, 3) #=> (2/3) * Rational(4, -6) #=> (-2/3) * 3.to_r #=> (3/1) * * You can also create rational object 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 * program 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 has inexact factor (numerical value or * operation), 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; #undef rb_intern #define rb_intern(str) rb_intern_const(str) assert(fprintf(stderr, "assert() is now active\n")); id_abs = rb_intern("abs"); id_cmp = rb_intern("<=>"); id_convert = rb_intern("convert"); id_eqeq_p = rb_intern("=="); id_expt = rb_intern("**"); id_fdiv = rb_intern("fdiv"); id_idiv = rb_intern("div"); id_integer_p = rb_intern("integer?"); id_negate = rb_intern("-@"); id_to_f = rb_intern("to_f"); id_to_i = rb_intern("to_i"); id_truncate = rb_intern("truncate"); id_i_num = rb_intern("@numerator"); id_i_den = rb_intern("@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"); #if 0 rb_define_private_method(CLASS_OF(rb_cRational), "new!", nurat_s_new_bang, -1); rb_define_private_method(CLASS_OF(rb_cRational), "new", nurat_s_new, -1); #else rb_undef_method(CLASS_OF(rb_cRational), "new"); #endif 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, "+", nurat_add, 1); rb_define_method(rb_cRational, "-", nurat_sub, 1); rb_define_method(rb_cRational, "*", nurat_mul, 1); rb_define_method(rb_cRational, "/", nurat_div, 1); rb_define_method(rb_cRational, "quo", nurat_div, 1); rb_define_method(rb_cRational, "fdiv", nurat_fdiv, 1); rb_define_method(rb_cRational, "**", nurat_expt, 1); rb_define_method(rb_cRational, "<=>", nurat_cmp, 1); rb_define_method(rb_cRational, "==", nurat_eqeq_p, 1); rb_define_method(rb_cRational, "coerce", nurat_coerce, 1); #if 0 /* NUBY */ rb_define_method(rb_cRational, "//", nurat_idiv, 1); #endif #if 0 rb_define_method(rb_cRational, "quot", nurat_quot, 1); rb_define_method(rb_cRational, "quotrem", nurat_quotrem, 1); #endif #if 0 rb_define_method(rb_cRational, "rational?", nurat_true, 0); rb_define_method(rb_cRational, "exact?", nurat_true, 0); #endif 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); 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", numeric_quo, 1); rb_define_method(rb_cInteger, "numerator", integer_numerator, 0); rb_define_method(rb_cInteger, "denominator", integer_denominator, 0); rb_define_method(rb_cFloat, "numerator", float_numerator, 0); rb_define_method(rb_cFloat, "denominator", float_denominator, 0); rb_define_method(rb_cNilClass, "to_r", nilclass_to_r, 0); rb_define_method(rb_cNilClass, "rationalize", nilclass_rationalize, -1); 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 */ } /* Local variables: c-file-style: "ruby" End: */