# another product.
# Mathematical operations
-package math
+module math
import kernel
import collection
+in "C header" `{
+#include <math.h>
+`}
+
redef class Int
+ # Returns a random `Int` in `[0 .. self[`.
fun rand: Int is extern "kernel_Int_Int_rand_0"
+
+ # Returns the result of a binary AND operation on `self` and `i`
+ #
+ # assert 0x10.bin_and(0x01) == 0
+ fun bin_and(i: Int): Int is extern "kernel_Int_Int_binand_0"
+
+ # Returns the result of a binary OR operation on `self` and `i`
+ #
+ # assert 0x10.bin_or(0x01) == 0x11
+ fun bin_or(i: Int): Int is extern "kernel_Int_Int_binor_0"
+
+ # Returns the result of a binary XOR operation on `self` and `i`
+ #
+ # assert 0x101.bin_xor(0x110) == 0x11
+ fun bin_xor(i: Int): Int is extern "kernel_Int_Int_binxor_0"
+
+ # Returns the 1's complement of `self`
+ #
+ # assert 0x2F.bin_not == -48
+ fun bin_not: Int is extern "kernel_Int_Int_binnot_0"
+
+ # Returns the square root of `self`
+ #
+ # assert 16.sqrt == 4
+ 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
+
+ # Is `self` even ?
+ #
+ # assert 12.is_even
+ fun is_even: Bool do return self % 2 == 0
+
+ # Is `self` odd ?
+ #
+ # assert not 13.is_even
+ fun is_odd: Bool do return not is_even
+
+ # Returns the `self` raised to the power of `e`.
+ #
+ # assert 2 ** 3 == 8
+ fun **(e: Int): Int
+ do
+ return self.to_f.pow(e.to_f).to_i
+ end
+
+ # The factorial of `self` (aka `self!`)
+ #
+ # Returns `1 * 2 * 3 * ... * self-1 * self`
+ #
+ # assert 0.factorial == 1 # by convention for an empty product
+ # assert 1.factorial == 1
+ # assert 4.factorial == 24
+ # assert 9.factorial == 362880
+ fun factorial: Int
+ do
+ assert self >= 0
+ var res = 1
+ var n = self
+ while n > 0 do
+ res = res * n
+ n -= 1
+ end
+ return res
+ end
end
redef class Float
+
+ # Returns the non-negative square root of `self`.
+ #
+ # assert 9.0.sqrt == 3.0
+ # #assert 3.0.sqrt == 1.732
+ # assert 1.0.sqrt == 1.0
+ # assert 0.0.sqrt == 0.0
fun sqrt: Float is extern "kernel_Float_Float_sqrt_0"
+
+ # Computes the cosine of `self` (expressed in radians).
+ #
+ # #assert pi.cos == -1.0
fun cos: Float is extern "kernel_Float_Float_cos_0"
+
+ # Computes the sine of `self` (expressed in radians).
+ #
+ # #assert pi.sin == 0.0
fun sin: Float is extern "kernel_Float_Float_sin_0"
+
+ # Computes the cosine of x (expressed in radians).
+ #
+ # #assert 0.0.tan == 0.0
fun tan: Float is extern "kernel_Float_Float_tan_0"
+
+ # Computes the arc cosine of `self`.
+ #
+ # #assert 0.0.acos == pi / 2.0
fun acos: Float is extern "kernel_Float_Float_acos_0"
+
+ # Computes the arc sine of `self`.
+ #
+ # #assert 1.0.asin == pi / 2.0
fun asin: Float is extern "kernel_Float_Float_asin_0"
+
+ # Computes the arc tangent of `self`.
+ #
+ # #assert 0.0.tan == 0.0
fun atan: Float is extern "kernel_Float_Float_atan_0"
+ # Returns the absolute value of `self`.
+ #
+ # assert 12.0.abs == 12.0
+ # assert (-34.56).abs == 34.56
+ # assert -34.56.abs == -34.56
+ fun abs: Float `{ return fabs(recv); `}
+
+ # Returns `self` raised at `e` power.
+ #
+ # #assert 2.0.pow(0.0) == 1.0
+ # #assert 2.0.pow(3.0) == 8.0
+ # #assert 0.0.pow(9.0) == 0.0
fun pow(e: Float): Float is extern "kernel_Float_Float_pow_1"
+
+ # Returns the logarithm of `self`.
+ #
+ # assert 0.0.log.is_inf == -1
+ # #assert 1.0.log == 0.0
fun log: Float is extern "kernel_Float_Float_log_0"
+
+ # Returns *e* raised to `self`.
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); `}
+
+ # Rounds the value of a float to its nearest integer value
+ #
+ # assert 1.67.round == 2.0
+ # assert 1.34.round == 1.0
+ # assert -1.34.round == -1.0
+ # assert -1.67.round == -2.0
+ fun round: Float is extern "round"
+ # 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"
+
+ # Returns the euclidean distance from `b`.
+ fun hypot_with(b : Float): Float is extern "hypotf"
+
+ # Returns true is self is not a number.
+ 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 ]
- fun rand : nullable E
+ # Return a random element form the collection
+ # There must be at least one element in the collection
+ fun rand: E
do
- if is_empty then return null
-
+ if is_empty then abort
var rand_index = length.rand
- var picked : nullable E = null
- iterate !each( e ) do
- if rand_index == 0
- then
- picked = e
- break
- else
- rand_index -= 1
- end
+ for e in self do
+ if rand_index == 0 then return e
+ rand_index -= 1
end
+ abort
+ end
+end
- return picked
+redef class SequenceRead[E]
+ # Optimized for large collections using `[]`
+ redef fun rand
+ do
+ assert not is_empty
+ return self[length.rand]
end
end
+redef class Sys
+ init
+ do
+ srand
+ end
+end
+
+# Computes the arc tangent given `x` and `y`.
+#
+# assert atan2(-0.0, 1.0) == -0.0
+# assert atan2(0.0, 1.0) == 0.0
fun atan2(x: Float, y: Float): Float is extern "kernel_Any_Any_atan2_2"
+
+# Approximate value of **pi**.
fun pi: Float is extern "kernel_Any_Any_pi_0"
+
+# Initialize the pseudo-random generator with the given seed.
+# The pseudo-random generator is used by the method `rand` and other to generate sequence of numbers.
+# These sequences are repeatable by calling `srand_from` with a same seed value.
+#
+# ~~~~
+# srand_from(0)
+# var a = 10.rand
+# var b = 100.rand
+# srand_from(0)
+# assert 10.rand == a
+# assert 100.rand == b
+# ~~~~
fun srand_from(x: Int) is extern "kernel_Any_Any_srand_from_1"
+
+# Reinitialize the pseudo-random generator used by the method `rand` and other.
+# This method is automatically invoked at the begin of the program, so usually, there is no need to manually invoke it.
+# The only exception is in conjunction with `srand_from` to reset the pseudo-random generator.
fun srand is extern "kernel_Any_Any_srand_0"
nitlanguage / nit.git / blobdiff