宏生成代码 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 19 元编程 189 19.1 程序表示 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 实现的类型推导和即时编译（JIT）技术。Julia 是一门支持过程式、函数式和面向对象的多范式语言。 它像 R、MATLAB 和 Python 一样简单，在高级数值计算方面有丰富的表现力，并且支持通用编程。为 了实现这个目标，Julia 以数学编程语言（mathematical programming languages）为基础，同时也参考 了不少流行的动态语言，例如 Lisp、Perl、Python、Lua、和 Ruby。 类型系统和多重派发是 Julia 语言最主要的特征，但一般不需要显式地手动标注或使用：函数通过函 数名称和不同类型参数的组合进行定义，在调用时会派发到最接近（most specific）的定义上去。这 样的编程模型非常适合数学化的编程，尤其是在传统的面向对象派发中，一些函数的第一个变量理 论上并不“拥有”这样一个操作时。在 Julia 中运算符只是函数的一个特殊标记——例如，为用户定 义的新类型添加加法运算，你只要为

for inspecting graphs, flamegraphs and more • ProfileCanvas.jl is a HTML canvas based profile viewer UI, used by the Julia VS Code extension, but can also generate interactive HTML files. An entirely independent 34-element Array{String,1}: ".circleci" ".freebsdci.sh" ".git" ".gitattributes" ".github" "test" "ui" "usr" "usr-staging" julia> pwd() "/home/JuliaUser" source Base.Filesystem.readdir – Function ulia") julia> readdir() 30-element Array{String,1}: ".appveyor.yml" ".git" ".gitattributes" "ui" "usr" "usr-staging" julia> readdir(join=true) 30-element Array{String,1}: "/home/JuliaUser/dev/julia/

for inspecting graphs, flamegraphs and more • ProfileCanvas.jl is a HTML canvas based profile viewer UI, used by the Julia VS Code extension, but can also generate interactive HTML files. An entirely independent 34-element Array{String,1}: ".circleci" ".freebsdci.sh" ".git" ".gitattributes" ".github" "test" "ui" "usr" "usr-staging" julia> pwd() "/home/JuliaUser" source Base.Filesystem.readdir – Function ulia") julia> readdir() 30-element Array{String,1}: ".appveyor.yml" ".git" ".gitattributes" "ui" "usr" "usr-staging" julia> readdir(join=true) 30-element Array{String,1}: "/home/JuliaUser/dev/julia/

for inspecting graphs, flamegraphs and more • ProfileCanvas.jl is a HTML canvas based profile viewer UI, used by the Julia VS Code extension, but can also generate interactive HTML files. An entirely independent 100%|████████████████████████████████| Time: 0:00:00 Main binary filename not available. Serving web UI on http://localhost:62261 "alloc-profile.pb.gz" Then you can view the profile by navigating to h 34-element Array{String,1}: ".circleci" ".freebsdci.sh" ".git" ".gitattributes" ".github" "test" "ui" "usr" "usr-staging" julia> pwd() "/home/JuliaUser" source Base.Filesystem.readdir – Function

for inspecting graphs, flamegraphs and more • ProfileCanvas.jl is a HTML canvas based profile viewer UI, used by the Julia VS Code extension, but can also generate interactive HTML files. An entirely independent 100%|████████████████████████████████| Time: 0:00:00 Main binary filename not available. Serving web UI on http://localhost:62261 "alloc-profile.pb.gz" Then you can view the profile by navigating to h 34-element Array{String,1}: ".circleci" ".freebsdci.sh" ".git" ".gitattributes" ".github" "test" "ui" "usr" "usr-staging" julia> pwd() "/home/JuliaUser" source Base.Filesystem.readdir – Function

for inspecting graphs, flamegraphs and more • ProfileCanvas.jl is a HTML canvas based profile viewer UI, used by the Julia VS Code extension, but can also generate interactive HTML files. An entirely independent 100%|████████████████████████████████| Time: 0:00:00 Main binary filename not available. Serving web UI on http://localhost:62261 "alloc-profile.pb.gz" Then you can view the profile by navigating to h 34-element Array{String,1}: ".circleci" ".freebsdci.sh" ".git" ".gitattributes" ".github" "test" "ui" "usr" "usr-staging" julia> pwd() "/home/JuliaUser" source Base.Filesystem.readdir – Function

for inspecting graphs, flamegraphs and more • ProfileCanvas.jl is a HTML canvas based profile viewer UI, used by the Julia VS Code extension, but can also generate interactive HTML files. An entirely independent 100%|████████████████████████████████| Time: 0:00:00 Main binary filename not available. Serving web UI on http://localhost:62261 "alloc-profile.pb.gz" Then you can view the profile by navigating to h 34-element Vector{String}: ".circleci" ".freebsdci.sh" ".git" ".gitattributes" ".github" "test" "ui" "usr" "usr-staging" julia> pwd() "/home/JuliaUser" source Base.Filesystem.readdir – Function

for inspecting graphs, flamegraphs and more • ProfileCanvas.jl is a HTML canvas based profile viewer UI, used by the Julia VS Code extension, but can also generate interactive HTML files. An entirely independent 100%|████████████████████████████████| Time: 0:00:00 Main binary filename not available. Serving web UI on http://localhost:62261 "alloc-profile.pb.gz" Then you can view the profile by navigating to h 34-element Vector{String}: ".circleci" ".freebsdci.sh" ".git" ".gitattributes" ".github" "test" "ui" "usr" "usr-staging" julia> pwd() "/home/JuliaUser" source Base.Filesystem.readdir – Function

for inspecting graphs, flamegraphs and more • ProfileCanvas.jl is a HTML canvas based profile viewer UI, used by the Julia VS Code extension, but can also generate interactive HTML files. An entirely independent 100%|████████████████████████████████| Time: 0:00:00 Main binary filename not available. Serving web UI on http://localhost:62261 "alloc-profile.pb.gz" Then you can view the profile by navigating to h 34-element Vector{String}: ".circleci" ".freebsdci.sh" ".git" ".gitattributes" ".github" "test" "ui" "usr" "usr-staging" julia> pwd() "/home/JuliaUser" source Base.Filesystem.readdir – Function

for inspecting graphs, flamegraphs and more • ProfileCanvas.jl is a HTML canvas based profile viewer UI, used by the Julia VS Code extension, but can also generate interactive HTML files. An entirely independent 100%|████████████████████████████████| Time: 0:00:00 Main binary filename not available. Serving web UI on http://localhost:62261 "alloc-profile.pb.gz" Then you can view the profile by navigating to h 34-element Vector{String}: ".circleci" ".freebsdci.sh" ".git" ".gitattributes" ".github" "test" "ui" "usr" "usr-staging" julia> pwd() "/home/JuliaUser" source Base.Filesystem.readdir – Function