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# 单行注释只需要一个井号
#= 多行注释
只需要以 '#=' 开始 '=#' 结束
还可以嵌套.
=#
####################################################
## 1. 原始类型与操作符
####################################################
# Julia 中一切皆为表达式
# 这是一些基本数字类型
typeof(3) # => Int64
typeof(3.2) # => Float64
typeof(2 + 1im) # => Complex{Int64}
typeof(2 // 3) # => Rational{Int64}
# 支持所有的普通中缀操作符
1 + 1 # => 2
8 - 1 # => 7
10 * 2 # => 20
35 / 5 # => 7.0
10 / 2 # => 5.0 # 整数除法总是返回浮点数
div(5, 2) # => 2 # 使用 div 可以获得整除的结果
5 \ 35 # => 7.0
2^2 # => 4 # 幂运算,不是异或 (xor)
12 % 10 # => 2
# 用括号提高优先级
(1 + 3) * 2 # => 8
# 位操作符
~2 # => -3 # 按位非 (not)
3 & 5 # => 1 # 按位与 (and)
2 | 4 # => 6 # 按位或 (or)
xor(2, 4) # => 6 # 按位异或 (xor)
2 >>> 1 # => 1 # 逻辑右移
2 >> 1 # => 1 # 算术右移
2 << 1 # => 4 # 逻辑/算术左移
# 可以用函数 bitstring 查看二进制数。
bitstring(12345)
# => "0000000000000000000000000000000000000000000000000011000000111001"
bitstring(12345.0)
# => "0100000011001000000111001000000000000000000000000000000000000000"
# 布尔值是原始类型
true
false
# 布尔操作符
!true # => false
!false # => true
1 == 1 # => true
2 == 1 # => false
1 != 1 # => false
2 != 1 # => true
1 < 10 # => true
1 > 10 # => false
2 <= 2 # => true
2 >= 2 # => true
# 链式比较
1 < 2 < 3 # => true
2 < 3 < 2 # => false
# 字符串可以由 " 创建
"This is a string."
# 字符字面量可用 ' 创建
'a'
# 可以像取数组取值一样用 index 取出对应字符
ascii("This is a string")[1] # => 'T'
# Julia 的 index 从 1 开始 :(
# 但是对 UTF-8 无效,
# 因此建议使用遍历器 (map, for loops, 等).
# $ 可用于字符插值:
"2 + 2 = $(2 + 2)" # => "2 + 2 = 4"
# 可以将任何 Julia 表达式放入括号。
# 另一种输出格式化字符串的方法是使用标准库 Printf 中的 Printf 宏
using Printf
@printf "%d is less than %f\n" 4.5 5.3 # => 5 is less than 5.300000
# 打印字符串很容易
println("I'm Julia. Nice to meet you!")
# 字符串可以按字典序进行比较
"good" > "bye" # => true
"good" == "good" # => true
"1 + 2 = 3" == "1 + 2 = $(1 + 2)" # => true
####################################################
## 2. 变量与集合
####################################################
# 给变量赋值就是声明变量
some_var = 5 # => 5
some_var # => 5
# 访问未声明变量会抛出异常
try
some_other_var # => ERROR: UndefVarError: some_other_var not defined
catch e
println(e)
end
# 变量名必须以下划线或字母开头
# 之后任何字母,数字,下划线,叹号都是合法的。
SomeOtherVar123! = 6 # => 6
# 甚至可以用 unicode 字符
☃ = 8 # => 8
# 用数学符号非常方便
2 * π # => 6.283185307179586
# 注意 Julia 的命名规约:
#
# * 变量名为小写,单词之间以下划线连接 "_" 。
#
# * 类型名以大写字母开头,单词以 CamelCase 方式连接。
#
# * 函数与宏的名字小写,无下划线。
#
# * 会改变输入的函数名末位为 !。
# 这类函数有时被称为 mutating functions 或 in-place functions.
# 数组存储一列值,index 从 1 开始
a = Int64[] # => 0-element Array{Int64,1}
# 一维数组可以以逗号分隔值的方式声明
b = [4, 5, 6] # => 3-element Array{Int64,1}: [4, 5, 6]
b = [4; 5; 6] # => 3-element Array{Int64,1}: [4, 5, 6]
b[1] # => 4
b[end] # => 6
# 二维数组以分号分隔维度
matrix = [1 2; 3 4] # => 2×2 Array{Int64,2}: [1 2; 3 4]
# 指定数组的类型
b = Int8[4, 5, 6] # => 3-element Array{Int8,1}: [4, 5, 6]
# 使用 push! 和 append! 往数组末尾添加元素
push!(a, 1) # => [1]
push!(a, 2) # => [1,2]
push!(a, 4) # => [1,2,4]
push!(a, 3) # => [1,2,4,3]
append!(a, b) # => [1,2,4,3,4,5,6]
# 用 pop 弹出尾部的元素
pop!(b) # => 6
b # => [4,5]
# 再放回去
push!(b, 6) # => [4,5,6]
b # => [4,5,6]
a[1] # => 1 # 永远记住 Julia 的引索从 1 开始!而不是 0!
# 用 end 可以直接取到最后索引. 可用作任何索引表达式
a[end] # => 6
# 数组还支持 popfirst! 和 pushfirst!
popfirst!(a) # => 1
a # => [2,4,3,4,5,6]
pushfirst!(a, 7) # => [7,2,4,3,4,5,6]
a # => [7,2,4,3,4,5,6]
# 以叹号结尾的函数名表示它会改变参数的值
arr = [5,4,6] # => 3-element Array{Int64,1}: [5,4,6]
sort(arr) # => [4,5,6]
arr # => [5,4,6]
sort!(arr) # => [4,5,6]
arr # => [4,5,6]
# 数组越界会抛出 BoundsError
try
a[0]
# => ERROR: BoundsError: attempt to access 7-element Array{Int64,1} at
# index [0]
# => Stacktrace:
# => [1] getindex(::Array{Int64,1}, ::Int64) at .\array.jl:731
# => [2] top-level scope at none:0
# => [3] ...
# => in expression starting at ...\LearnJulia.jl:188
a[end + 1]
# => ERROR: BoundsError: attempt to access 7-element Array{Int64,1} at
# index [8]
# => Stacktrace:
# => [1] getindex(::Array{Int64,1}, ::Int64) at .\array.jl:731
# => [2] top-level scope at none:0
# => [3] ...
# => in expression starting at ...\LearnJulia.jl:196
catch e
println(e)
end
# 报错时错误会指出出错的文件位置以及行号,标准库也一样
# 你可以在 Julia 安装目录下的 share/julia 文件夹里找到这些标准库
# 可以用 range 初始化数组
a = [1:5;] # => 5-element Array{Int64,1}: [1,2,3,4,5]
# 可以切割数组
a[1:3] # => [1, 2, 3]
a[2:end] # => [2, 3, 4, 5]
# 用 splice! 切割原数组
arr = [3,4,5]
splice!(arr, 2) # => 4
arr # => [3,5]
# 用 append! 连接数组
b = [1,2,3]
append!(a, b) # => [1, 2, 3, 4, 5, 1, 2, 3]
a # => [1, 2, 3, 4, 5, 1, 2, 3]
# 检查元素是否在数组中
in(1, a) # => true
# 用 length 获得数组长度
length(a) # => 8
# 元组(Tuples)是不可变的
tup = (1, 2, 3) # => (1,2,3)
typeof(tup) # => Tuple{Int64,Int64,Int64}
tup[1] # => 1
try
tup[1] = 3
# => ERROR: MethodError: no method matching
# setindex!(::Tuple{Int64,Int64,Int64}, ::Int64, ::Int64)
catch e
println(e)
end
# 大多数组的函数同样支持元组
length(tup) # => 3
tup[1:2] # => (1,2)
in(2, tup) # => true
# 可以将元组的元素解包赋给变量
a, b, c = (1, 2, 3) # => (1,2,3)
a # => 1
b # => 2
c # => 3
# 不用括号也可以
d, e, f = 4, 5, 6 # => (4,5,6)
d # => 4
e # => 5
f # => 6
# 单元素 tuple 不等于其元素值
(1,) == 1 # => false
(1) == 1 # => true
# 交换值
e, d = d, e # => (5,4)
d # => 5
e # => 4
# 字典Dictionaries store mappings
empty_dict = Dict() # => Dict{Any,Any} with 0 entries
# 也可以用字面量创建字典
filled_dict = Dict("one" => 1, "two" => 2, "three" => 3)
# => Dict{String,Int64} with 3 entries:
# => "two" => 2, "one" => 1, "three" => 3
# 用 [] 获得键值
filled_dict["one"] # => 1
# 获得所有键
keys(filled_dict)
# => Base.KeySet for a Dict{String,Int64} with 3 entries. Keys:
# => "two", "one", "three"
# 注意,键的顺序不是插入时的顺序
# 获得所有值
values(filled_dict)
# => Base.ValueIterator for a Dict{String,Int64} with 3 entries. Values:
# => 2, 1, 3
# 注意,值的顺序也一样
# 用 in 检查键值是否已存在,用 haskey 检查键是否存在
in(("one" => 1), filled_dict) # => true
in(("two" => 3), filled_dict) # => false
haskey(filled_dict, "one") # => true
haskey(filled_dict, 1) # => false
# 获取不存在的键的值会抛出异常
try
filled_dict["four"] # => ERROR: KeyError: key "four" not found
catch e
println(e)
end
# 使用 get 可以提供默认值来避免异常
# get(dictionary,key,default_value)
get(filled_dict, "one", 4) # => 1
get(filled_dict, "four", 4) # => 4
# Sets 表示无序不可重复的值的集合
empty_set = Set() # => Set(Any[])
# 初始化一个带初值的 Set
filled_set = Set([1, 2, 2, 3, 4]) # => Set([4, 2, 3, 1])
# 新增值
push!(filled_set, 5) # => Set([4, 2, 3, 5, 1])
# 检查 Set 中是否存在某值
in(2, filled_set) # => true
in(10, filled_set) # => false
# 交集,并集,差集
other_set = Set([3, 4, 5, 6]) # => Set([4, 3, 5, 6])
intersect(filled_set, other_set) # => Set([4, 3, 5])
union(filled_set, other_set) # => Set([4, 2, 3, 5, 6, 1])
setdiff(Set([1,2,3,4]), Set([2,3,5])) # => Set([4, 1])
####################################################
## 3. 控制语句
####################################################
# 声明一个变量
some_var = 5
# 这是一个 if 语句块,其中的缩进不是必须的
if some_var > 10
println("some_var is totally bigger than 10.")
elseif some_var < 10 # elseif 是可选的
println("some_var is smaller than 10.")
else # else 也是可选的
println("some_var is indeed 10.")
end
# => some_var is smaller than 10.
# For 循环遍历
# 可迭代的类型包括:Range, Array, Set, Dict 和 AbstractString
for animal = ["dog", "cat", "mouse"]
println("$animal is a mammal")
# 你可以用 $ 将变量或表达式插入字符串中
end
# => dog is a mammal
# => cat is a mammal
# => mouse is a mammal
# 你也可以不用 '=' 而使用 'in'
for animal in ["dog", "cat", "mouse"]
println("$animal is a mammal")
end
# => dog is a mammal
# => cat is a mammal
# => mouse is a mammal
for pair in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal")
from, to = pair
println("$from is a $to")
end
# => mouse is a mammal
# => cat is a mammal
# => dog is a mammal
# 注意!这里的输出顺序和上面的不同
for (k, v) in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal")
println("$k is a $v")
end
# => mouse is a mammal
# => cat is a mammal
# => dog is a mammal
# While 循环
let x = 0
while x < 4
println(x)
x += 1 # x = x + 1 的缩写
end
end
# => 0
# => 1
# => 2
# => 3
# 用 try/catch 处理异常
try
error("help")
catch e
println("caught it $e")
end
# => caught it ErrorException("help")
####################################################
## 4. 函数
####################################################
# 关键字 'function' 用于定义函数
# function name(arglist)
# body...
# end
function add(x, y)
println("x is $x and y is $y")
# 函数会返回最后一行的值
x + y
end
add(5, 6)
# => x is 5 and y is 6
# => 11
# 更紧凑的定义函数
f_add(x, y) = x + y # => f_add (generic function with 1 method)
f_add(3, 4) # => 7
# 函数可以将多个值作为元组返回
fn(x, y) = x + y, x - y # => fn (generic function with 1 method)
fn(3, 4) # => (7, -1)
# 还可以定义接收可变长参数的函数
function varargs(args...)
return args
# 使用 return 可以在函数内的任何地方返回
end
# => varargs (generic function with 1 method)
varargs(1,2,3) # => (1,2,3)
# 省略号 ... 称为 splat
# 刚刚用在了函数定义中
# 在调用函数时也可以使用它,此时它会把数组或元组解包为参数列表
add([5,6]...) # 等价于 add(5,6)
x = (5, 6) # => (5,6)
add(x...) # 等价于 add(5,6)
# 可定义带可选参数的函数
function defaults(a, b, x=5, y=6)
return "$a $b and $x $y"
end
# => defaults (generic function with 3 methods)
defaults('h', 'g') # => "h g and 5 6"
defaults('h', 'g', 'j') # => "h g and j 6"
defaults('h', 'g', 'j', 'k') # => "h g and j k"
try
defaults('h') # => ERROR: MethodError: no method matching defaults(::Char)
defaults() # => ERROR: MethodError: no method matching defaults()
catch e
println(e)
end
# 还可以定义带关键字参数的函数
function keyword_args(;k1=4, name2="hello") # 注意分号 ';'
return Dict("k1" => k1, "name2" => name2)
end
# => keyword_args (generic function with 1 method)
keyword_args(name2="ness") # => ["name2"=>"ness", "k1"=>4]
keyword_args(k1="mine") # => ["name2"=>"hello", "k1"=>"mine"]
keyword_args() # => ["name2"=>"hello", "k1"=>4]
# 可以在一个函数中组合各种类型的参数
function all_the_args(normal_arg, optional_positional_arg=2; keyword_arg="foo")
println("normal arg: $normal_arg")
println("optional arg: $optional_positional_arg")
println("keyword arg: $keyword_arg")
end
# => all_the_args (generic function with 2 methods)
all_the_args(1, 3, keyword_arg=4)
# => normal arg: 1
# => optional arg: 3
# => keyword arg: 4
# Julia 有一等函数
function create_adder(x)
adder = function (y)
return x + y
end
return adder
end
# => create_adder (generic function with 1 method)
# 这是用 "stabby lambda syntax" 创建的匿名函数
(x -> x > 2)(3) # => true
# 这个函数和上面的 create_adder 是等价的
function create_adder(x)
y -> x + y
end
# => create_adder (generic function with 1 method)
# 你也可以给内部函数起个名字
function create_adder(x)
function adder(y)
x + y
end
adder
end
# => create_adder (generic function with 1 method)
add_10 = create_adder(10) # => (::getfield(Main, Symbol("#adder#11")){Int64})
# (generic function with 1 method)
add_10(3) # => 13
# 内置的高阶函数有
map(add_10, [1,2,3]) # => [11, 12, 13]
filter(x -> x > 5, [3, 4, 5, 6, 7]) # => [6, 7]
# 还可以使用 list comprehensions 让 map 更美观
[add_10(i) for i = [1, 2, 3]] # => [11, 12, 13]
[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13]
####################################################
## 5. 类型
####################################################
# Julia 有类型系统
# 所有的值都有类型;但变量本身没有类型
# 你可以用 `typeof` 函数获得值的类型
typeof(5) # => Int64
# 类型是一等值
typeof(Int64) # => DataType
typeof(DataType) # => DataType
# DataType 是代表类型的类型,也代表他自己的类型
# 类型可用于文档化代码、执行优化以及多重派分(dispatch)
# Julia 并不只是静态的检查类型
# 用户还可以自定义类型
# 就跟其它语言的 records 或 structs 一样
# 用 `struct` 关键字定义新的类型
# struct Name
# field::OptionalType
# ...
# end
struct Tiger
taillength::Float64
coatcolor # 不带类型标注相当于 `::Any`
end
# 默认构造函数的参数是类型的属性,按类型定义中的顺序排列
tigger = Tiger(3.5, "orange") # => Tiger(3.5, "orange")
# 用新类型作为构造函数还会创建一个类型
sherekhan = typeof(tigger)(5.6, "fire") # => Tiger(5.6, "fire")
# 类似 struct 的类型被称为具体类型
# 它们可被实例化,但不能有子类型
# 另一种类型是抽象类型
# 抽象类型名
abstract type Cat end # 仅仅是指向类型结构层次的一个名称
# 抽象类型不能被实例化,但可以有子类型
# 例如,Number 就是抽象类型
subtypes(Number) # => 2-element Array{Any,1}:
# => Complex
# => Real
subtypes(Cat) # => 0-element Array{Any,1}
# AbstractString,类如其名,也是一个抽象类型
subtypes(AbstractString) # => 4-element Array{Any,1}:
# => String
# => SubString
# => SubstitutionString
# => Test.GenericString
# 所有的类型都有父类型。可以用函数 `supertype` 得到父类型
typeof(5) # => Int64
supertype(Int64) # => Signed
supertype(Signed) # => Integer
supertype(Integer) # => Real
supertype(Real) # => Number
supertype(Number) # => Any
supertype(supertype(Signed)) # => Real
supertype(Any) # => Any
# 除了 Int64 外,其余的类型都是抽象类型
typeof("fire") # => String
supertype(String) # => AbstractString
supertype(AbstractString) # => Any
supertype(SubString) # => AbstractString
# <: 是子类型化操作符
struct Lion <: Cat # Lion 是 Cat 的子类型
mane_color
roar::AbstractString
end
# 可以继续为你的类型定义构造函数
# 只需要定义一个与类型同名的函数,并调用已有的构造函数得到正确的类型
Lion(roar::AbstractString) = Lion("green", roar) # => Lion
# 这是一个外部构造函数,因为它在类型定义之外
struct Panther <: Cat # Panther 也是 Cat 的子类型
eye_color
Panther() = new("green")
# Panthers 只有这个构造函数,没有默认构造函数
end
# 像 Panther 一样使用内置构造函数,让你可以控制如何构建类型的值
# 应该尽量使用外部构造函数,而不是内部构造函数
####################################################
## 6. 多分派
####################################################
# Julia 中所有的函数都是通用函数,或者叫做泛型函数(generic functions)
# 也就是说这些函数都是由许多小方法组合而成的
# Lion 的每一种构造函数都是通用函数 Lion 的一个方法
# 我们来看一个非构造函数的例子
# 首先,让我们定义一个函数 meow
# Lion, Panther, Tiger 的 meow 定义分别为
function meow(animal::Lion)
animal.roar # 使用点记号 '.' 访问属性
end
function meow(animal::Panther)
"grrr"
end
function meow(animal::Tiger)
"rawwwr"
end
# 试试 meow 函数
meow(tigger) # => "rawwwr"
meow(Lion("brown", "ROAAR")) # => "ROAAR"
meow(Panther()) # => "grrr"
# 回顾类型的层次结构
Tiger <: Cat # => false
Lion <: Cat # => true
Panther <: Cat # => true
# 定义一个接收 Cat 类型的函数
function pet_cat(cat::Cat)
println("The cat says $(meow(cat))")
end
# => pet_cat (generic function with 1 method)
pet_cat(Lion("42")) # => The cat says 42
try
pet_cat(tigger) # => ERROR: MethodError: no method matching pet_cat(::Tiger)
catch e
println(e)
end
# 在面向对象语言中,通常都是单分派
# 这意味着使用的方法取决于第一个参数的类型
# 而 Julia 中选择方法时会考虑到所有参数的类型
# 让我们定义一个有更多参数的函数,这样我们就能看出区别
function fight(t::Tiger, c::Cat)
println("The $(t.coatcolor) tiger wins!")
end
# => fight (generic function with 1 method)
fight(tigger, Panther()) # => The orange tiger wins!
fight(tigger, Lion("ROAR")) # => fight(tigger, Lion("ROAR"))
# 让我们修改一下传入 Lion 类型时的行为
fight(t::Tiger, l::Lion) = println("The $(l.mane_color)-maned lion wins!")
# => fight (generic function with 2 methods)
fight(tigger, Panther()) # => The orange tiger wins!
fight(tigger, Lion("ROAR")) # => The green-maned lion wins!
# 我们不需要一只老虎参与战斗
fight(l::Lion, c::Cat) = println("The victorious cat says $(meow(c))")
# => fight (generic function with 3 methods)
fight(Lion("balooga!"), Panther()) # => The victorious cat says grrr
try
fight(Panther(), Lion("RAWR"))
# => ERROR: MethodError: no method matching fight(::Panther, ::Lion)
# => Closest candidates are:
# => fight(::Tiger, ::Lion) at ...
# => fight(::Tiger, ::Cat) at ...
# => fight(::Lion, ::Cat) at ...
# => ...
catch e
println(e)
end
# 试试把 Cat 放在前面
fight(c::Cat, l::Lion) = println("The cat beats the Lion")
# => fight (generic function with 4 methods)
# 由于无法判断该使用哪个 fight 方法,而产生了错误
try
fight(Lion("RAR"), Lion("brown", "rarrr"))
# => ERROR: MethodError: fight(::Lion, ::Lion) is ambiguous. Candidates:
# => fight(c::Cat, l::Lion) in Main at ...
# => fight(l::Lion, c::Cat) in Main at ...
# => Possible fix, define
# => fight(::Lion, ::Lion)
# => ...
catch e
println(e)
end
# 在不同版本的 Julia 中错误信息可能有所不同
fight(l::Lion, l2::Lion) = println("The lions come to a tie")
# => fight (generic function with 5 methods)
fight(Lion("RAR"), Lion("brown", "rarrr")) # => The lions come to a tie
# Under the hood
# 你还可以看看 llvm 以及它生成的汇编代码
square_area(l) = l * l # => square_area (generic function with 1 method)
square_area(5) # => 25
# 当我们喂给 square_area 一个整数时会发生什么?
code_native(square_area, (Int32,))
# .text
# ; Function square_area {
# ; Location: REPL[49]:1
# pushq %rbp
# movq %rsp, %rbp
# ; Function *; {
# ; Location: int.jl:54
# imull %ecx, %ecx
# ;}
# movl %ecx, %eax
# popq %rbp
# retq
# nopl (%rax,%rax)
# ;}
code_native(square_area, (Float32,))
# .text
# ; Function square_area {
# ; Location: REPL[49]:1
# pushq %rbp
# movq %rsp, %rbp
# ; Function *; {
# ; Location: float.jl:398
# vmulss %xmm0, %xmm0, %xmm0
# ;}
# popq %rbp
# retq
# nopw (%rax,%rax)
# ;}
code_native(square_area, (Float64,))
# .text
# ; Function square_area {
# ; Location: REPL[49]:1
# pushq %rbp
# movq %rsp, %rbp
# ; Function *; {
# ; Location: float.jl:399
# vmulsd %xmm0, %xmm0, %xmm0
# ;}
# popq %rbp
# retq
# nopw (%rax,%rax)
# ;}
# 注意!只要参数中有浮点数,Julia 就会使用浮点指令
# 让我们计算一下圆的面积
circle_area(r) = pi * r * r # => circle_area (generic function with 1 method)
circle_area(5) # => 78.53981633974483
code_native(circle_area, (Int32,))
# .text
# ; Function circle_area {
# ; Location: REPL[53]:1
# pushq %rbp
# movq %rsp, %rbp
# ; Function *; {
# ; Location: operators.jl:502
# ; Function *; {
# ; Location: promotion.jl:314
# ; Function promote; {
# ; Location: promotion.jl:284
# ; Function _promote; {
# ; Location: promotion.jl:261
# ; Function convert; {
# ; Location: number.jl:7
# ; Function Type; {
# ; Location: float.jl:60
# vcvtsi2sdl %ecx, %xmm0, %xmm0
# movabsq $532051920, %rax # imm = 0x1FB677D0
# ;}}}}}
# ; Function *; {
# ; Location: float.jl:399
# vmulsd (%rax), %xmm0, %xmm1
# vmulsd %xmm0, %xmm1, %xmm0
# ;}}
# popq %rbp
# retq
# nopl (%rax)
# ;}
code_native(circle_area, (Float64,))
# .text
# ; Function circle_area {
# ; Location: REPL[53]:1
# pushq %rbp
# movq %rsp, %rbp
# movabsq $532052040, %rax # imm = 0x1FB67848
# ; Function *; {
# ; Location: operators.jl:502
# ; Function *; {
# ; Location: promotion.jl:314
# ; Function *; {
# ; Location: float.jl:399
# vmulsd (%rax), %xmm0, %xmm1
# ;}}}
# ; Function *; {
# ; Location: float.jl:399
# vmulsd %xmm0, %xmm1, %xmm0
# ;}
# popq %rbp
# retq
# nopl (%rax,%rax)
# ;}