diff --git a/ChangeLog b/ChangeLog index b452e01636..4e00267e31 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,7 @@ +Fri Jun 19 20:39:46 2009 Tadayoshi Funaba + + * rational.c: added rdoc. a patch from Run Paint Run Run. + Fri Jun 19 17:04:59 2009 Yukihiro Matsumoto * numeric.c (flo_cmp): should always return nil for NaN. diff --git a/rational.c b/rational.c index ecc0752174..0da742a9b1 100644 --- a/rational.c +++ b/rational.c @@ -512,6 +512,20 @@ 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 of _rat_ as an +Integer+ object. + * + * For example: + * + * Rational(7).numerator #=> 7 + * Rational(7, 1).numerator #=> 7 + * Rational(4.3, 40.3).numerator #=> 4841369599423283 + * Rational(9, -4).numerator #=> -9 + * Rational(-2, -10).numerator #=> 1 + */ static VALUE nurat_numerator(VALUE self) { @@ -519,6 +533,22 @@ nurat_numerator(VALUE self) return dat->num; } + +/* + * call-seq: + * rat.denominator => integer + * + * Returns the denominator of _rat_ as an +Integer+ object. If _rat_ was + * created without an explicit denominator, +1+ is returned. + * + * For example: + * + * Rational(7).denominator #=> 1 + * Rational(7, 1).denominator #=> 1 + * Rational(4.3, 40.3).denominator #=> 45373766245757744 + * Rational(9, -4).denominator #=> 4 + * Rational(-2, -10).denominator #=> 5 + */ static VALUE nurat_denominator(VALUE self) { @@ -611,6 +641,26 @@ f_addsub(VALUE self, VALUE anum, VALUE aden, VALUE bnum, VALUE bden, int k) return f_rational_new_no_reduce2(CLASS_OF(self), num, den); } +/* + * call-seq: + * rat + numeric => numeric_result + * + * Performs addition. The class of the resulting object depends on + * the class of _numeric_ and on the magnitude of the + * result. + * + * A +TypeError+ is raised unless _numeric_ is a +Numeric+ object. + * + * For example: + * + * 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 + * Rational(8, 7) + 2**20 #=> (7340040/7) + */ + static VALUE nurat_add(VALUE self, VALUE other) { @@ -639,6 +689,24 @@ nurat_add(VALUE self, VALUE other) } } +/* + * call-seq: + * rat - numeric => numeric_result + * + * Performs subtraction. The class of the resulting object depends on the + * class of _numeric_ and on the magnitude of the result. + * + * A +TypeError+ is raised unless _numeric_ is a +Numeric+ object. + * + * For example: + * + * 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 + * Rational(8, 7) - 2**20 #=> (-7340024/7) + */ static VALUE nurat_sub(VALUE self, VALUE other) { @@ -706,6 +774,24 @@ f_muldiv(VALUE self, VALUE anum, VALUE aden, VALUE bnum, VALUE bden, int k) return f_rational_new_no_reduce2(CLASS_OF(self), num, den); } +/* + * call-seq: + * rat * numeric => numeric_result + * + * Performs multiplication. The class of the resulting object depends on + * the class of _numeric_ and on the magnitude of the result. + * + * A +TypeError+ is raised unless _numeric_ is a +Numeric+ object. + * + * For example: + * + * 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 + * Rational(8, 7) * 2**20 #=> (8388608/7) + */ static VALUE nurat_mul(VALUE self, VALUE other) { @@ -734,6 +820,28 @@ nurat_mul(VALUE self, VALUE other) } } +/* + * call-seq: + * rat / numeric => numeric_result + * rat.quo(numeric) => numeric_result + * + * Performs division. The class of the resulting object depends on the class + * of _numeric_ and on the magnitude of the result. + * + * A +TypeError+ is raised unless _numeric_ is a +Numeric+ object. A + * +ZeroDivisionError+ is raised if _numeric_ is 0. + * + * For example: + * + * 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 + * Rational(8, 7) / 2**20 #=> (1/917504) + * Rational(2, 13) / 0 #=> ZeroDivisionError: divided by zero + * Rational(2, 13) / 0.0 #=> Infinity + */ static VALUE nurat_div(VALUE self, VALUE other) { @@ -766,12 +874,49 @@ nurat_div(VALUE self, VALUE other) } } +/* + * call-seq: + * rat.fdiv(numeric) => float + * + * Performs float division: dividing _rat_ by _numeric_. The return value is a + * +Float+ object. + * + * A +TypeError+ is raised unless _numeric_ is a +Numeric+ object. + * + * For example: + * + * Rational(2, 3).fdiv(1) #=> 0.6666666666666666 + * Rational(2, 3).fdiv(0.5) #=> 1.3333333333333333 + * Rational(2).fdiv(3) #=> 0.6666666666666666 + * Rational(-9, 6.6).fdiv(6.6) #=> -0.20661157024793392 + * Rational(-20).fdiv(0.0) #=> -Infinity + */ static VALUE nurat_fdiv(VALUE self, VALUE other) { return f_to_f(f_div(self, other)); } +/* + * call-seq: + * rat ** numeric => numeric_result + * + * Performs exponentiation, i.e. it raises _rat_ to the exponent _numeric_. + * The class of the resulting object depends on the class of _numeric_ and on + * the magnitude of the result. A +TypeError+ is raised unless _numeric_ is a + * +Numeric+ object. + * + * For example: + * + * Rational(2, 3) ** Rational(2, 3) #=> 0.7631428283688879 + * Rational(900) ** Rational(1) #=> (900/1) + * Rational(-2, 9) ** Rational(-9, 2) #=> NaN + * Rational(9, 8) ** 4 #=> (6561/4096) + * Rational(20, 9) ** 9.8 #=> 2503.325740344559 + * Rational(3, 2) ** 2**3 #=> (6561/256) + * Rational(2, 13) ** 0 #=> (1/1) + * Rational(2, 13) ** 0.0 #=> 1.0 + */ static VALUE nurat_expt(VALUE self, VALUE other) { @@ -817,6 +962,27 @@ nurat_expt(VALUE self, VALUE other) } } +/* + * call-seq: + * rat <=> numeric => -1, 0, +1 + * + * Performs comparison. Returns -1, 0, or +1 depending on whether _rat_ is + * less than, equal to, or greater than _numeric_. This is the basis for the + * tests in +Comparable+. + * + * A +TypeError+ is raised unless _numeric_ is a +Numeric+ object. + * + * For example: + * + * Rational(2, 3) <=> Rational(2, 3) #=> 0 + * Rational(5) <=> 5 #=> 0 + * Rational(900) <=> Rational(1) #=> 1 + * Rational(-2, 9) <=> Rational(-9, 2) #=> 1 + * Rational(9, 8) <=> 4 #=> -1 + * Rational(20, 9) <=> 9.8 #=> -1 + * Rational(5, 3) <=> 'string' #=> TypeError: String can't + * # be coerced into Rational + */ static VALUE nurat_cmp(VALUE self, VALUE other) { @@ -854,6 +1020,22 @@ nurat_cmp(VALUE self, VALUE other) } } +/* + * call-seq: + * rat == numeric => +true+ or +false+ + * + * Tests for equality. Returns +true+ if _rat_ is equal to _numeric_; +false+ + * otherwise. + * + * For example: + * + * Rational(2, 3) == Rational(2, 3) #=> +true+ + * Rational(5) == 5 #=> +true+ + * Rational(7, 1) == Rational(7) #=> +true+ + * Rational(-2, 9) == Rational(-9, 2) #=> +false+ + * Rational(9, 8) == 4 #=> +false+ + * Rational(5, 3) == 'string' #=> +false+ + */ static VALUE nurat_equal_p(VALUE self, VALUE other) { @@ -891,6 +1073,26 @@ nurat_equal_p(VALUE self, VALUE other) } } +/* + * call-seq: + * rat.coerce(numeric) => array + * + * If _numeric_ is a +Rational+ object, returns an +Array+ containing _rat_ + * and _numeric_. Otherwise, returns an +Array+ with both _rat_ and _numeric_ + * represented in the most accurate common format. This coercion mechanism is + * used by Ruby to handle mixed-type numeric operations: it is intended to + * find a compatible common type between the two operands of the operator. + * + * For example: + * + * Rational(2).coerce(Rational(3)) #=> [(2), (3)] + * Rational(5).coerce(7) #=> [(7, 1), (5, 1)] + * Rational(9, 8).coerce(4) #=> [(4, 1), (9, 8)] + * Rational(7, 12).coerce(9.9876) #=> [9.9876, 0.5833333333333334] + * Rational(4).coerce(9/0.0) #=> [Infinity, 4.0] + * Rational(5, 3).coerce('string') #=> TypeError: String can't be + * # coerced into Rational + */ static VALUE nurat_coerce(VALUE self, VALUE other) { @@ -913,12 +1115,55 @@ nurat_coerce(VALUE self, VALUE other) return Qnil; } +/* + * call-seq: + * rat.div(numeric) => integer + * + * Uses +/+ to divide _rat_ by _numeric_, then returns the floor of the result + * as an +Integer+ object. + * + * A +TypeError+ is raised unless _numeric_ is a +Numeric+ object. A + * +ZeroDivisionError+ is raised if _numeric_ is 0. A +FloatDomainError+ is + * raised if _numeric_ is 0.0. + * + * For example: + * + * Rational(2, 3).div(Rational(2, 3)) #=> 1 + * Rational(-2, 9).div(Rational(-9, 2)) #=> 0 + * Rational(3, 4).div(0.1) #=> 7 + * Rational(-9).div(9.9) #=> -1 + * Rational(3.12).div(0.5) #=> 6 + * Rational(200, 51).div(0) #=> ZeroDivisionError: + * # divided by zero + */ static VALUE nurat_idiv(VALUE self, VALUE other) { return f_floor(f_div(self, other)); } +/* + * call-seq: + * rat.modulo(numeric) => numeric + * rat % numeric => numeric + * + * Returns the modulo of _rat_ and _numeric_ as a +Numeric+ object, i.e.: + * + * _rat_-_numeric_*(rat/numeric).floor + * + * A +TypeError+ is raised unless _numeric_ is a +Numeric+ object. A + * +ZeroDivisionError+ is raised if _numeric_ is 0. A +FloatDomainError+ is + * raised if _numeric_ is 0.0. + * + * For example: + * + * Rational(2, 3) % Rational(2, 3) #=> (0/1) + * Rational(2) % Rational(300) #=> (2/1) + * Rational(-2, 9) % Rational(9, -2) #=> (-2/9) + * Rational(8.2) % 3.2 #=> 1.799999999999999 + * Rational(198.1) % 2.3e3 #=> 198.1 + * Rational(2, 5) % 0.0 #=> FloatDomainError: Infinity + */ static VALUE nurat_mod(VALUE self, VALUE other) { @@ -926,6 +1171,28 @@ nurat_mod(VALUE self, VALUE other) return f_sub(self, f_mul(other, val)); } + +/* + * call-seq: + * rat.divmod(numeric) => array + * + * Returns a two-element +Array+ containing the quotient and modulus obtained + * by dividing _rat_ by _numeric_. Both elements are +Numeric+. + * + * A +ZeroDivisionError+ is raised if _numeric_ is 0. A +FloatDomainError+ is + * raised if _numeric_ is 0.0. A +TypeError+ is raised unless _numeric_ is a + * +Numeric+ object. + * + * For example: + * + * Rational(3).divmod(3) #=> [1, (0/1)] + * Rational(4).divmod(3) #=> [1, (1/1)] + * Rational(5).divmod(3) #=> [1, (2/1)] + * Rational(6).divmod(3) #=> [2, (0/1)] + * Rational(2, 3).divmod(Rational(2, 3)) #=> [1, (0/1)] + * Rational(-2, 9).divmod(Rational(9, -2)) #=> [0, (-2/9)] + * Rational(11.5).divmod(Rational(3.5)) #=> [3, (1/1)] + */ static VALUE nurat_divmod(VALUE self, VALUE other) { @@ -934,6 +1201,7 @@ nurat_divmod(VALUE self, VALUE other) } #if 0 +/* :nodoc: */ static VALUE nurat_quot(VALUE self, VALUE other) { @@ -941,6 +1209,27 @@ nurat_quot(VALUE self, VALUE other) } #endif +/* + * call-seq: rat.remainder(numeric) => numeric_result + * + * Returns the remainder of dividing _rat_ by _numeric_ as a +Numeric+ object, + * i.e.: + * + * _rat_-_numeric_*(_rat_/_numeric_).truncate + * + * A +ZeroDivisionError+ is raised if _numeric_ is 0. A +FloatDomainError+ is + * raised if the result is Infinity or NaN, or _numeric_ is 0.0. A +TypeError+ + * is raised unless _numeric_ is a +Numeric+ object. + * + * For example: + * + * Rational(3, 4).remainder(Rational(3)) #=> (3/4) + * Rational(12,13).remainder(-8) #=> (12/13) + * Rational(2,3).remainder(-Rational(3,2)) #=> (2/3) + * Rational(-5,7).remainder(7.1) #=> -0.7142857142857143 + * Rational(1).remainder(0) # ZeroDivisionError: + * # divided by zero + */ static VALUE nurat_rem(VALUE self, VALUE other) { @@ -949,6 +1238,7 @@ nurat_rem(VALUE self, VALUE other) } #if 0 +/* :nodoc: */ static VALUE nurat_quotrem(VALUE self, VALUE other) { @@ -957,6 +1247,21 @@ nurat_quotrem(VALUE self, VALUE other) } #endif +/* + * call-seq: + * rat.abs => rational + * + * Returns the absolute value of _rat_. If _rat_ is positive, it is + * returned; if _rat_ is negative its negation is returned. The return value + * is a +Rational+ object. + * + * For example: + * + * Rational(2).abs #=> (2/1) + * Rational(-2).abs #=> (2/1) + * Rational(-8, -1).abs #=> (8/1) + * Rational(-20, 7).abs #=> (20/7) + */ static VALUE nurat_abs(VALUE self) { @@ -966,6 +1271,7 @@ nurat_abs(VALUE self) } #if 0 +/* :nodoc: */ static VALUE nurat_true(VALUE self) { @@ -987,6 +1293,21 @@ nurat_ceil(VALUE self) return f_negate(f_idiv(f_negate(dat->num), dat->den)); } + +/* + * call-seq: + * rat.to_i => integer + * + * Returns _rat_ truncated to an integer as an +Integer+ object. + * + * For example: + * + * 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) { @@ -1047,30 +1368,157 @@ nurat_round_common(int argc, VALUE *argv, VALUE self, return s; } +/* + * call-seq: + * rat.floor => integer + * rat.floor(precision=0) => numeric + * + * Returns the largest integer less than or equal to _rat_ as an +Integer+ + * object. Contrast with +Rational#ceil+. + * + * An optional _precision_ argument can be supplied as an +Integer+. If + * _precision_ is positive the result is rounded downwards to that number of + * decimal places. If _precision_ is negative, the result is rounded downwards + * to the nearest 10**_precision_. By default _precision_ is equal to 0, + * causing the result to be a whole number. + * + * For example: + * + * Rational(2, 3).floor #=> 0 + * Rational(3).floor #=> 3 + * Rational(300.6).floor #=> 300 + * Rational(98,71).floor #=> 1 + * Rational(-30,2).floor #=> -15 + * + * Rational(-1.125).floor.to_f #=> -2.0 + * Rational(-1.125).floor(1).to_f #=> -1.2 + * Rational(-1.125).floor(2).to_f #=> -1.13 + * Rational(-1.125).floor(-2).to_f #=> -100.0 + * Rational(-1.125).floor(-1).to_f #=> -10.0 + */ static VALUE nurat_floor_n(int argc, VALUE *argv, VALUE self) { return nurat_round_common(argc, argv, self, nurat_floor); } +/* + * call-seq: + * rat.ceil => integer + * rat.ceil(precision=0) => numeric + * + * Returns the smallest integer greater than or equal to _rat_ as an +Integer+ + * object. Contrast with +Rational#floor+. + * + * An optional _precision_ argument can be supplied as an +Integer+. If + * _precision_ is positive the result is rounded upwards to that number of + * decimal places. If _precision_ is negative, the result is rounded upwards + * to the nearest 10**_precision_. By default _precision_ is equal to 0, + * causing the result to be a whole number. + * + * For example: + * + * Rational(2, 3).ceil #=> 1 + * Rational(3).ceil #=> 3 + * Rational(300.6).ceil #=> 301 + * Rational(98, 71).ceil #=> 2 + * Rational(-30, 2).ceil #=> -15 + * + * Rational(-1.125).ceil.to_f #=> -1.0 + * Rational(-1.125).ceil(1).to_f #=> -1.1 + * Rational(-1.125).ceil(2).to_f #=> -1.12 + * Rational(-1.125).ceil(-2).to_f #=> 0.0 + */ static VALUE nurat_ceil_n(int argc, VALUE *argv, VALUE self) { return nurat_round_common(argc, argv, self, nurat_ceil); } +/* + * call-seq: + * rat.truncate => integer + * rat.truncate(precision=0) => numeric + * + * Truncates self to an integer and returns the result as an +Integer+ object. + * + * An optional _precision_ argument can be supplied as an +Integer+. If + * _precision_ is positive the result is rounded downwards to that number of + * decimal places. If _precision_ is negative, the result is rounded downwards + * to the nearest 10**_precision_. By default _precision_ is equal to 0, + * causing the result to be a whole number. + * + * For example: + * + * Rational(2, 3).truncate #=> 0 + * Rational(3).truncate #=> 3 + * Rational(300.6).truncate #=> 300 + * Rational(98,71).truncate #=> 1 + * Rational(-30,2).truncate #=> -15 + * Rational(-30, -11).truncate #=> 2 + * + * Rational(-123.456).truncate(2).to_f #=> -123.45 + * Rational(-123.456).truncate(1).to_f #=> -123.4 + * Rational(-123.456).truncate.to_f #=> -123.0 + * Rational(-123.456).truncate(-1).to_f #=> -120.0 + * Rational(-123.456).truncate(-2).to_f #=> -100.0 + */ static VALUE nurat_truncate_n(int argc, VALUE *argv, VALUE self) { return nurat_round_common(argc, argv, self, nurat_truncate); } +/* + * call-seq: + * rat.round => integer + * rat.round(precision=0) => numeric + * + * Rounds _rat_ to an integer, and returns the result as an +Integer+ object. + * + * An optional _precision_ argument can be supplied as an +Integer+. If + * _precision_ is positive the result is rounded to that number of decimal + * places. If _precision_ is negative, the result is rounded to the nearest + * 10**_precision_. By default _precision_ is equal to 0, causing the result + * to be a whole number. + * + * A +TypeError+ is raised if _integer_ is given and not an +Integer+ object. + * + * For example: + * + * Rational(9, 3.3).round #=> 3 + * Rational(9, 3.3).round(1) #=> (27/10) + * Rational(9,3.3).round(2) #=> (273/100) + * Rational(8, 7).round(5) #=> (57143/50000) + * Rational(-20, -3).round #=> 7 + * + * Rational(-123.456).round(2).to_f #=> -123.46 + * Rational(-123.456).round(1).to_f #=> -123.5 + * Rational(-123.456).round.to_f #=> -123.0 + * Rational(-123.456).round(-1).to_f #=> -120.0 + * Rational(-123.456).round(-2).to_f #=> -100.0 + * + */ static VALUE nurat_round_n(int argc, VALUE *argv, VALUE self) { return nurat_round_common(argc, argv, self, nurat_round); } +/* + * call-seq: + * rat.to_f => float + * + * Converts _rat_ to a floating point number and returns the result as a + * +Float+ object. + * + * For example: + * + * 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) { @@ -1078,6 +1526,18 @@ nurat_to_f(VALUE self) return f_fdiv(dat->num, dat->den); } +/* + * call-seq: + * rat.to_r => self + * + * Returns self, i.e. a +Rational+ object representing _rat_. + * + * For example: + * + * Rational(2).to_r #=> (2/1) + * Rational(-8, 6).to_r #=> (-4/3) + * Rational(39.2).to_r #=> (2758454771764429/70368744177664) + */ static VALUE nurat_to_r(VALUE self) { @@ -1113,12 +1573,38 @@ nurat_format(VALUE self, VALUE (*func)(VALUE)) return s; } +/* + * call-seq: + * rat.to_s => string + * + * Returns a +String+ representation of _rat_ in the form + * "_numerator_/_denominator_". + * + * For example: + * + * Rational(2).to_s #=> "2/1" + * Rational(-8, 6).to_s #=> "-4/3" + * Rational(0.5).to_s #=> "1/2" + */ static VALUE nurat_to_s(VALUE self) { return nurat_format(self, f_to_s); } +/* + * call-seq: + * rat.inspect => string + * + * Returns a +String+ containing a human-readable representation of _rat_ in + * the form "(_numerator_/_denominator_)". + * + * For example: + * + * Rational(2).to_s #=> "(2/1)" + * Rational(-8, 6).to_s #=> "(-4/3)" + * Rational(0.5).to_s #=> "(1/2)" + */ static VALUE nurat_inspect(VALUE self) { @@ -1131,6 +1617,7 @@ nurat_inspect(VALUE self) return s; } +/* :nodoc: */ static VALUE nurat_marshal_dump(VALUE self) { @@ -1142,6 +1629,7 @@ nurat_marshal_dump(VALUE self) return a; } +/* :nodoc: */ static VALUE nurat_marshal_load(VALUE self, VALUE a) { @@ -1158,6 +1646,23 @@ nurat_marshal_load(VALUE self, VALUE a) /* --- */ +/* + * call-seq: + * int.gcd(_int2_) => integer + * + * Returns the greatest common divisor of _int_ and _int2_: the largest + * positive integer that divides the two without a remainder. The result is an + * +Integer+ object. + * + * An +ArgumentError+ is raised unless _int2_ is an +Integer+ object. + * + * For example: + * + * 2.gcd(2) #=> 2 + * -2.gcd(2) #=> 2 + * 8.gcd(6) #=> 2 + * 25.gcd(5) #=> 5 + */ VALUE rb_gcd(VALUE self, VALUE other) { @@ -1165,6 +1670,23 @@ rb_gcd(VALUE self, VALUE other) return f_gcd(self, other); } +/* + * call-seq: + * int.lcm(_int2_) => integer + * + * Returns the least common multiple (or "lowest common multiple") of _int_ + * and _int2_: the smallest positive integer that is a multiple of both + * integers. The result is an +Integer+ object. + * + * An +ArgumentError+ is raised unless _int2_ is an +Integer+ object. + * + * For example: + * + * 2.lcm(2) #=> 2 + * -2.gcd(2) #=> 2 + * 8.gcd(6) #=> 24 + * 8.lcm(9) #=> 72 + */ VALUE rb_lcm(VALUE self, VALUE other) { @@ -1172,6 +1694,25 @@ rb_lcm(VALUE self, VALUE other) return f_lcm(self, other); } +/* + * call-seq: + * int.gcdlcm(_int2_) => array + * + * Returns a two-element +Array+ containing _int_.gcd(_int2_) and + * _int_.lcm(_int2_) respectively. That is, the greatest common divisor of + * _int_ and _int2_, then the least common multiple of _int_ and _int2_. Both + * elements are +Integer+ objects. + * + * An +ArgumentError+ is raised unless _int2_ is an +Integer+ object. + * + * For example: + * + * 2.gcdlcm(2) #=> [2, 2] + * -2.gcdlcm(2) #=> [2, 2] + * 8.gcdlcm(6) #=> [2, 24] + * 8.gcdlcm(9) #=> [1, 72] + * 9.gcdlcm(9**9) #=> [9, 387420489] + */ VALUE rb_gcdlcm(VALUE self, VALUE other) { @@ -1253,12 +1794,34 @@ float_denominator(VALUE self) return rb_call_super(0, 0); } +/* + * call-seq: + * nil.to_r => Rational(0, 1) + * + * Returns a +Rational+ object representing _nil_ as a rational number. + * + * For example: + * + * nil.to_r #=> (0/1) + */ static VALUE nilclass_to_r(VALUE self) { return rb_rational_new1(INT2FIX(0)); } + +/* + * call-seq: + * int.to_r => rational + * + * Returns a +Rational+ object representing _int_ as a rational number. + * + * For example: + * + * 1.to_r #=> (1/1) + * 12.to_r #=> (12/1) + */ static VALUE integer_to_r(VALUE self) { @@ -1289,6 +1852,21 @@ float_decode(VALUE self) } #endif +/* + * call-seq: + * flt.to_r => rational + * + * Returns _flt_ as an +Rational+ object. Raises a +FloatDomainError+ if _flt_ + * is +Infinity+ or +NaN+. + * + * For example: + * + * 2.0.to_r #=> (2/1) + * 2.5.to_r #=> (5/2) + * -0.75.to_r #=> (-3/4) + * 0.0.to_r #=> (0/1) + * (1/0.0).to_r #=> FloatDomainError: Infinity + */ static VALUE float_to_r(VALUE self) { @@ -1433,6 +2011,24 @@ string_to_r_strict(VALUE self) #define id_gsub rb_intern("gsub") #define f_gsub(x,y,z) rb_funcall(x, id_gsub, 2, y, z) +/* + * call-seq: + * string.to_r => rational + * + * Returns a +Rational+ object representing _string_ as a rational number. + * Leading and trailing whitespace is ignored. Underscores may be used to + * separate numbers. If _string_ is not recognised as a rational, (0/1) is + * returned. + * + * For example: + * + * "2".to_r #=> (2/1) + * "300/2".to_r #=> (150/1) + * "-9.2/3".to_r #=> (-46/15) + * " 2/9 ".to_r #=> (2/9) + * "2_9".to_r #=> (29/1) + * "?".to_r #=> (0/1) + */ static VALUE string_to_r(VALUE self) { @@ -1529,6 +2125,70 @@ nurat_s_convert(int argc, VALUE *argv, VALUE klass) } } +/* + * A +Rational+ object represents a rational number, which is any number that + * can be expressed as the quotient a/b of two integers (where the denominator + * is nonzero). Given that b may be equal to 1, every integer is rational. + * + * A +Rational+ object can be created with the +Rational()+ constructor: + * + * Rational(1) #=> (1/1) + * Rational(2, 3) #=> (2/3) + * Rational(0.5) #=> (1/2) + * Rational("2/7") #=> (2/7) + * Rational("0.25") #=> (1/4) + * Rational(10e3) #=> (10000/1) + * + * The first argument is the numerator, the second the denominator. If the + * denominator is not supplied it defaults to 1. The arguments can be + * +Numeric+ or +String+ objects. + * + * Rational(12) == Rational(12, 1) #=> true + * + * A +ZeroDivisionError+ will be raised if 0 is specified as the denominator: + * + * Rational(3, 0) #=> ZeroDivisionError: divided by zero + * + * The numerator and denominator of a +Rational+ object can be retrieved with + * the +Rational#numerator+ and +Rational#denominator+ accessors, + * respectively. + * + * rational = Rational(4, 7) #=> (4/7) + * rational.numerator #=> 4 + * rational.denominator #=> 7 + * + * A +Rational+ is automatically reduced into its simplest form: + * + * Rational(10, 2) #=> (5/1) + * + * +Numeric+ and +String+ objects can be converted into a +Rational+ with + * their +#to_r+ methods. + * + * 30.to_r #=> (30/1) + * 3.33.to_r #=> (1874623344892969/562949953421312) + * '33/3'.to_r #=> (11/1) + * + * The reverse operations work as you would expect: + * + * Rational(30, 1).to_i #=> 30 + * Rational(1874623344892969, 562949953421312).to_f #=> 3.33 + * Rational(11, 1).to_s #=> "11/1" + * + * +Rational+ objects can be compared with other +Numeric+ objects using the + * normal semantics: + * + * Rational(20, 10) == Rational(2, 1) #=> true + * Rational(10) > Rational(1) #=> true + * Rational(9, 2) <=> Rational(8, 3) #=> 1 + * + * Similarly, standard mathematical operations support +Rational+ objects, too: + * + * Rational(9, 2) * 2 #=> (9/1) + * Rational(12, 29) / Rational(2,3) #=> (18/29) + * Rational(7,5) + Rational(60) #=> (307/5) + * Rational(22, 5) - Rational(5, 22) #=> (459/110) + * Rational(2,3) ** 3 #=> (8/27) + */ void Init_Rational(void) { @@ -1553,7 +2213,7 @@ Init_Rational(void) id_to_s = rb_intern("to_s"); id_truncate = rb_intern("truncate"); - rb_cRational = rb_define_class(RATIONAL_NAME, rb_cNumeric); + 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"); @@ -1593,7 +2253,7 @@ Init_Rational(void) rb_define_method(rb_cRational, "divmod", nurat_divmod, 1); #if 0 - rb_define_method(rb_cRational, "quot", nurat_quot, 1); + rb_define_method(rb_cRational, "quot", nurat_quot, 1); #endif rb_define_method(rb_cRational, "remainder", nurat_rem, 1); #if 0