# Returns the square root of `self`
#
# assert 16.sqrt == 4
- fun sqrt: Int `{ return sqrt(recv); `}
+ fun sqrt: Int `{ return sqrt(self); `}
# Returns the greatest common divisor of `self` and `o`
#
# assert 12.0.abs == 12.0
# assert (-34.56).abs == 34.56
# assert -34.56.abs == -34.56
- fun abs: Float `{ return fabs(recv); `}
+ fun abs: Float `{ return fabs(self); `}
# Returns `self` raised at `e` power.
#
# #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`.
+ # Natural 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"
+ # 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 is extern "kernel_Float_Float_exp_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 -1.34.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"
end
private fun is_inf_extern: Bool is extern "isinf"
+
+ # 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
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]
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