#
# This file is free software, which comes along with NIT. This software is
# distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
# PARTICULAR PURPOSE. You can modify it is you want, provided this header
# is kept unaltered, and a notification of the changes is added.
# You are allowed to redistribute it and sell it, alone or is a part of
# another product.
# Mathematical operations
-module math
+module math is ldflags "-lm"
import kernel
import collection
in "C header" `{
-#include <math.h>
+ #include <stdlib.h>
+ #include <math.h>
+ #include <time.h>
+`}
+
+in "C" `{
+ /* Is rand shortcut? */
+ static int nit_rand_seeded;
+ /* Current rand seed if seeded */
+ static unsigned int nit_rand_seed;
+
+ #define NIT_RAND_MAX 0x7fffffff
+
+ /* This algorithm is mentioned in the ISO C standard, here extended
+ for 32 bits. */
+ static int
+ nit_rand(void) {
+ unsigned int next = nit_rand_seed;
+ int result;
+
+ next *= 1103515245;
+ next += 12345;
+ result = (unsigned int) (next / 65536) % 2048;
+
+ next *= 1103515245;
+ next += 12345;
+ result <<= 10;
+ result ^= (unsigned int) (next / 65536) % 1024;
+
+ next *= 1103515245;
+ next += 12345;
+ result <<= 10;
+ result ^= (unsigned int) (next / 65536) % 1024;
+
+ nit_rand_seed = next;
+
+ return result;
+ }
`}
redef class Int
# Returns a random `Int` in `[0 .. self[`.
- fun rand: Int is extern "kernel_Int_Int_rand_0"
+ fun rand: Int `{
+ if (nit_rand_seeded) return (long)(((double)self)*nit_rand()/(NIT_RAND_MAX+1.0));
+ return (long)(((double)self)*rand()/(RAND_MAX+1.0));
+ `}
# 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"
+ # assert 0x10 & 0x01 == 0
+ fun &(i: Int): Int `{ return self & i; `}
# 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"
+ # assert 0x10 | 0x01 == 0x11
+ fun |(i: Int): Int `{ return self | i; `}
# 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"
+ # assert 0x101 ^ 0x110 == 0x11
+ fun ^(i: Int): Int `{ return self ^ i; `}
# Returns the 1's complement of `self`
#
- # assert 0x2F.bin_not == -48
- fun bin_not: Int is extern "kernel_Int_Int_binnot_0"
+ # assert ~0x2F == -48
+ fun ~: Int `{ return ~self; `}
# Returns the square root of `self`
#
- # assert 16.sqrt == 4
- fun sqrt: Int `{ return sqrt(recv); `}
+ # assert 16.sqrt == 4
+ fun sqrt: Int `{ return sqrt(self); `}
# Returns the greatest common divisor of `self` and `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)
+ if self & 1 == 0 then
+ if o & 1 == 1 then
+ return (self >> 1).gcd(o)
else
- return self.rshift(1).gcd(o.rshift(1)).lshift(1)
+ return (self >> 1).gcd(o >> 1) << 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)
+ if o & 1 == 0 then return self.gcd(o >> 1)
+ if self > o then return ((self - o) >> 1).gcd(o)
+ return ((o - self) >> 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
+
+ # Is self a prime number ?
+ #
+ # assert 3.is_prime
+ # assert not 1.is_prime
+ # assert not 12.is_prime
+ fun is_prime: Bool
+ do
+ if self == 2 then
+ return true
+ else if self <= 1 or self.is_even then
+ return false
+ end
+ for i in [3..self.sqrt[ do
+ if self % i == 0 then return false
+ end
+ return true
+ end
+
+ # 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 Byte
+ # Returns the result of a binary AND operation on `self` and `i`
+ #
+ # assert 0x10u8 & 0x01u8 == 0u8
+ fun &(i: Byte): Byte `{ return self & i; `}
+
+ # Returns the result of a binary OR operation on `self` and `i`
+ #
+ # assert 0x10u8 | 0x01u8 == 0x11u8
+ fun |(i: Byte): Byte `{ return self | i; `}
+
+ # Returns the result of a binary XOR operation on `self` and `i`
+ #
+ # assert 0x101u8 ^ 0x110u8 == 0x11u8
+ fun ^(i: Byte): Byte `{ return self ^ i; `}
+
+ # Returns the 1's complement of `self`
+ #
+ # assert ~0x2Fu8 == 0xD0u8
+ fun ~: Byte `{ return ~self; `}
+end
+
redef class Float
- fun sqrt: Float is extern "kernel_Float_Float_sqrt_0"
- fun cos: Float is extern "kernel_Float_Float_cos_0"
- fun sin: Float is extern "kernel_Float_Float_sin_0"
- fun tan: Float is extern "kernel_Float_Float_tan_0"
- 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 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"
+
+ # 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 `{ return sqrt(self); `}
+
+ # Computes the cosine of `self` (expressed in radians).
+ #
+ # #assert pi.cos == -1.0
+ fun cos: Float `{ return cos(self); `}
+
+ # Computes the sine of `self` (expressed in radians).
+ #
+ # #assert pi.sin == 0.0
+ fun sin: Float `{ return sin(self); `}
+
+ # Computes the cosine of x (expressed in radians).
+ #
+ # #assert 0.0.tan == 0.0
+ fun tan: Float `{ return tan(self); `}
+
+ # Computes the arc cosine of `self`.
+ #
+ # #assert 0.0.acos == pi / 2.0
+ fun acos: Float `{ return acos(self); `}
+
+ # Computes the arc sine of `self`.
+ #
+ # #assert 1.0.asin == pi / 2.0
+ fun asin: Float `{ return asin(self); `}
+
+ # Computes the arc tangent of `self`.
+ #
+ # #assert 0.0.tan == 0.0
+ fun atan: Float `{ return atan(self); `}
+
+ # 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(self); `}
+
+ # 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 `{ return pow(self, e); `}
+
+ # Natural logarithm of `self`.
+ #
+ # assert 0.0.log.is_inf == -1
+ # #assert 1.0.log == 0.0
+ fun log: Float `{ return log(self); `}
+
+ # Logarithm of `self` to base `base`.
+ #
+ # assert 100.0.log_base(10.0) == 2.0
+ # assert 256.0.log_base(2.0) == 8.0
+ fun log_base(base: Float): Float do return log/base.log
+
+ # Returns *e* raised to `self`.
+ fun exp: Float `{ return exp(self); `}
# 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); `}
+ fun ceil: Float `{ return ceil(self); `}
# 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); `}
-
+ fun floor: Float `{ return floor(self); `}
+
+ # 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 `{ return round(self); `}
+
# 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 rand: Float `{
+ if (nit_rand_seeded) return ((self)*nit_rand())/(NIT_RAND_MAX+1.0);
+ return ((self)*rand())/(RAND_MAX+1.0);
+ `}
- fun is_nan: Bool is extern "isnan"
+ # Returns the euclidean distance from `b`.
+ fun hypot_with(b: Float): Float `{ return hypotf(self, b); `}
+
+ # Returns true is self is not a number.
+ #
+ # As `nan != nan`, `is_nan` should be used to test if a float is the special *not a number* value.
+ #
+ # ~~~
+ # assert nan != nan # By IEEE 754
+ # assert nan.is_nan
+ # assert not 10.0.is_nan
+ # ~~~
+ fun is_nan: Bool `{ return isnan(self); `}
# Is the float an infinite value
# this function returns:
# * 1 if self is positive infinity
# * -1 if self is negative infinity
# * 0 otherwise
+ #
+ # ~~~
+ # assert 10.0.is_inf == 0
+ # assert inf.is_inf == 1
+ # assert (-inf).is_inf == -1
+ # ~~~
fun is_inf: Int do
- if is_inf_extern then
+ if native_is_inf then
if self < 0.0 then return -1
return 1
end
return 0
end
- private fun is_inf_extern: Bool is extern "isinf"
+ private fun native_is_inf: Bool `{ return isinf(self); `}
+
+ # Linear interpolation between `a` and `b` using `self` as weight
+ #
+ # ~~~
+ # assert 0.0.lerp(0.0, 128.0) == 0.0
+ # assert 0.5.lerp(0.0, 128.0) == 64.0
+ # assert 1.0.lerp(0.0, 128.0) == 128.0
+ # assert -0.5.lerp(0.0, 128.0) == -64.0
+ # ~~~
+ fun lerp(a, b: Float): Float do return (1.0 - self) * a + self * b
end
+# Positive float infinite (IEEE 754)
+#
+# assert inf > 10.0
+# assert inf.is_inf == 1
+#
+# `inf` follows the arithmetic of infinites
+#
+# assert (inf - 1.0) == inf
+# assert (inf - inf).is_nan
+#
+# The negative infinite can be used as `-inf`.
+#
+# assert -inf < -10.0
+# assert (-inf).is_inf == -1
+fun inf: Float do return 1.0 / 0.0
+
+# Not a Number, representation of an undefined or unrepresentable float (IEEE 754).
+#
+# `nan` is not comparable with itself, you should use `Float::is_nan` to test it.
+#
+# ~~~
+# assert nan.is_nan
+# assert nan != nan # By IEEE 754
+# ~~~
+#
+# `nan` is the quiet result of some undefined operations.
+#
+# ~~~
+# assert (1.0 + nan).is_nan
+# assert (0.0 / 0.0).is_nan
+# assert (inf - inf).is_nan
+# assert (inf / inf).is_nan
+# assert (-1.0).sqrt.is_nan
+# ~~~
+fun nan: Float do return 0.0 / 0.0
+
redef class Collection[ E ]
# Return a random element form the collection
# There must be at least one element in the collection
+ #
+ # ~~~
+ # var x = [1,2,3].rand
+ # assert x == 1 or x == 2 or x == 3
+ # ~~~
fun rand: E
do
if is_empty then abort
end
abort
end
+
+ # Return a new array made of elements in a random order.
+ #
+ # ~~~
+ # var a = [1,2,1].to_shuffle
+ # assert a == [1,1,2] or a == [1,2,1] or a == [2,1,1]
+ # ~~~
+ fun to_shuffle: Array[E]
+ do
+ var res = self.to_a
+ res.shuffle
+ return res
+ end
+end
+
+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 AbstractArray[E]
+ # Reorder randomly the elements in self.
+ #
+ # ~~~
+ # var a = new Array[Int]
+ #
+ # a.shuffle
+ # assert a.is_empty
+ #
+ # a.add 1
+ # a.shuffle
+ # assert a == [1]
+ #
+ # a.add 2
+ # a.shuffle
+ # assert a == [1,2] or a == [2,1]
+ # ~~~
+ #
+ # ENSURE self.shuffle.has_exactly(old(self))
+ fun shuffle
+ do
+ for i in [0..length[ do
+ var j = i + (length-i).rand
+ var tmp = self[i]
+ self[i] = self[j]
+ self[j] = tmp
+ end
+ end
+end
+
+redef class Sys
+ init
+ do
+ srand
+ end
end
-fun atan2(x: Float, y: Float): Float is extern "kernel_Any_Any_atan2_2"
-fun pi: Float is extern "kernel_Any_Any_pi_0"
-fun srand_from(x: Int) is extern "kernel_Any_Any_srand_from_1"
-fun srand is extern "kernel_Any_Any_srand_0"
+# 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 `{ return atan2(x, y); `}
+
+# Approximate value of **pi**.
+fun pi: Float do return 3.14159265
+
+# 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) `{ nit_rand_seeded = 1; nit_rand_seed = x; `}
+
+# 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 `{ nit_rand_seeded = 0; srand(time(NULL)); `}