X-Git-Url: http://nitlanguage.org diff --git a/lib/standard/math.nit b/lib/standard/math.nit index d122c2e..7db6fa3 100644 --- a/lib/standard/math.nit +++ b/lib/standard/math.nit @@ -26,9 +26,31 @@ redef class Int fun bin_and(i: Int): Int is extern "kernel_Int_Int_binand_0" fun bin_or(i: Int): Int is extern "kernel_Int_Int_binor_0" fun bin_xor(i: Int): Int is extern "kernel_Int_Int_binxor_0" - fun sqrt : Int is extern `{ return sqrtl(recv); `} - fun sin : Int is extern `{ return sinl(recv); `} - fun cos : Int is extern `{ return cosl(recv); `} + fun sqrt: Int `{ return sqrt(recv); `} + # Returns the greatest common divisor of `self` and `o` + # + # assert 54.gcd(24) == 6 + # assert -54.gcd(-24) == 6 + # assert 54.gcd(-24) == -6 + # assert -54.gcd(24) == -6 + # assert 12.gcd(6) == 6 + fun gcd(o: Int): Int + do + if self < 0 then return -(-self).gcd(o) + if o < 0 then return -(self.gcd(-o)) + if self == 0 or o == self then return o + if o == 0 then return self + if self.bin_and(1) == 0 then + if o.bin_and(1) == 1 then + return self.rshift(1).gcd(o) + else + return self.rshift(1).gcd(o.rshift(1)).lshift(1) + end + end + if o.bin_and(1) == 0 then return self.gcd(o.rshift(1)) + if self > o then return (self - o).rshift(1).gcd(o) + return (o - self).rshift(1).gcd(self) + end end redef class Float @@ -39,14 +61,45 @@ redef class Float fun acos: Float is extern "kernel_Float_Float_acos_0" fun asin: Float is extern "kernel_Float_Float_asin_0" fun atan: Float is extern "kernel_Float_Float_atan_0" - fun abs: Float `{ return abs(recv); `} + fun abs: Float `{ return fabs(recv); `} fun pow(e: Float): Float is extern "kernel_Float_Float_pow_1" fun log: Float is extern "kernel_Float_Float_log_0" fun exp: Float is extern "kernel_Float_Float_exp_0" + + # assert 1.1.ceil == 2.0 + # assert 1.9.ceil == 2.0 + # assert 2.0.ceil == 2.0 + # assert (-1.5).ceil == -1.0 + fun ceil: Float `{ return ceil(recv); `} + + # assert 1.1.floor == 1.0 + # assert 1.9.floor == 1.0 + # assert 2.0.floor == 2.0 + # assert (-1.5).floor == -2.0 + fun floor: Float `{ return floor(recv); `} + # Returns a random `Float` in `[0.0 .. self[`. fun rand: Float is extern "kernel_Float_Float_rand_0" fun hypot_with( b : Float ) : Float is extern "hypotf" + + fun is_nan: Bool is extern "isnan" + + # Is the float an infinite value + # this function returns: + # + # * 1 if self is positive infinity + # * -1 if self is negative infinity + # * 0 otherwise + fun is_inf: Int do + if is_inf_extern then + if self < 0.0 then return -1 + return 1 + end + return 0 + end + + private fun is_inf_extern: Bool is extern "isinf" end redef class Collection[ E ]