多重对象 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 宏生成代码 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 19 元编程 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 19.4 代码生成 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 19.5 5 非标准字符串字面量 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 19.6 生成函数 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 一个高级的例子

by package actions which change the manifest. See Pkg.precompile. JULIA_PKG_SERVER Specifies the URL of the package registry to use. By default, Pkg uses https://pkg.julialang.org to fetch Julia packages ExponentialBackOff(n=3, first_delay=5, max_delay=1000)) retry(http_get, check=(s,e)->e.status == "503")(url) retry(read, check=(s,e)->isa(e, IOError))(io, 128; all=false) source Base.ExponentialBackOff – instead. source Base.download – Function. download(url::AbstractString, [path::AbstractString = tempname()]) -> path Download a file from the given url, saving it to the location path, or if not specified

by package actions which change the manifest. See Pkg.precompile. JULIA_PKG_SERVER Specifies the URL of the package registry to use. By default, Pkg uses https://pkg.julialang.org to fetch Julia packages ExponentialBackOff(n=3, first_delay=5, max_delay=1000)) retry(http_get, check=(s,e)->e.status == "503")(url) retry(read, check=(s,e)->isa(e, IOError))(io, 128; all=false) source Base.ExponentialBackOff – instead. source Base.download – Function. download(url::AbstractString, [path::AbstractString = tempname()]) -> path Download a file from the given url, saving it to the location path, or if not specified

by package actions which change the manifest. See Pkg.precompile. JULIA_PKG_SERVER Specifies the URL of the package registry to use. By default, Pkg uses https://pkg.julialang.org to fetch Julia packages ExponentialBackOff(n=3, first_delay=5, max_delay=1000)) retry(http_get, check=(s,e)->e.status == "503")(url) retry(read, check=(s,e)->isa(e, IOError))(io, 128; all=false) source Base.ExponentialBackOff – instead. source Base.download – Function. download(url::AbstractString, [path::AbstractString = tempname()]) -> path Download a file from the given url, saving it to the location path, or if not specified

ExponentialBackOff(n=3, first_delay=5, max_delay=1000)) retry(http_get, check=(s,e)->e.status == "503")(url) retry(read, check=(s,e)->isa(e, IOError))(io, 128; all=false) source Base.ExponentialBackOff – dst. source Base.download – Function. download(url::AbstractString, [path::AbstractString = tempname()]) -> path Download a file from the given url, saving it to the location path, or if not specified download(url, [ output = tempfile() ]; [ method = "GET", ] [ headers = , ] [ timeout = , ] [ progress = , ] [ verbose = false, ] [ downloader = , ] ) -> output url :: AbstractString

ExponentialBackOff(n=3, first_delay=5, max_delay=1000)) retry(http_get, check=(s,e)->e.status == "503")(url) retry(read, check=(s,e)->isa(e, IOError))(io, 128; all=false) source Base.ExponentialBackOff – dst. source Base.download – Function. download(url::AbstractString, [path::AbstractString = tempname()]) -> path Download a file from the given url, saving it to the location path, or if not specified download(url, [ output = tempfile() ]; [ method = "GET", ] [ headers = , ] [ timeout = , ] [ progress = , ] [ verbose = false, ] [ downloader = , ] ) -> output url :: AbstractString

ExponentialBackOff(n=3, first_delay=5, max_delay=1000)) retry(http_get, check=(s,e)->e.status == "503")(url) retry(read, check=(s,e)->isa(e, IOError))(io, 128; all=false) source Base.ExponentialBackOff – dst. source Base.download – Function. download(url::AbstractString, [path::AbstractString = tempname()]) -> path Download a file from the given url, saving it to the location path, or if not specified download(url, [ output = tempfile() ]; [ method = "GET", ] [ headers = , ] [ timeout = , ] [ progress = , ] [ verbose = false, ] [ downloader = , ] ) -> output url :: AbstractString

ExponentialBackOff(n=3, first_delay=5, max_delay=1000)) retry(http_get, check=(s,e)->e.status == "503")(url) retry(read, check=(s,e)->isa(e, IOError))(io, 128; all=false) source Base.ExponentialBackOff – dst. source Base.download – Function. download(url::AbstractString, [path::AbstractString = tempname()]) -> path Download a file from the given url, saving it to the location path, or if not specified download(url, [ output = tempfile() ]; [ method = "GET", ] [ headers = , ] [ timeout = , ] [ progress = , ] [ verbose = false, ] [ downloader = , ] ) -> output url :: AbstractString

ExponentialBackOff(n=3, first_delay=5, max_delay=1000)) retry(http_get, check=(s,e)->e.status == "503")(url) retry(read, check=(s,e)->isa(e, IOError))(io, 128; all=false) source Base.ExponentialBackOff – dst. source Base.download – Function. download(url::AbstractString, [path::AbstractString = tempname()]) -> path Download a file from the given url, saving it to the location path, or if not specified download(url, [ output = tempfile() ]; [ method = "GET", ] [ headers = , ] [ timeout = , ] [ progress = , ] [ verbose = false, ] [ downloader = , ] ) -> output url :: AbstractString

ExponentialBackOff(n=3, first_delay=5, max_delay=1000)) retry(http_get, check=(s,e)->e.status == "503")(url) retry(read, check=(s,e)->isa(e, IOError))(io, 128; all=false) source Base.ExponentialBackOff – dst. source Base.download – Function. download(url::AbstractString, [path::AbstractString = tempname()]) -> path Download a file from the given url, saving it to the location path, or if not specified download(url, [ output = tempfile() ]; [ method = "GET", ] [ headers = , ] [ timeout = , ] [ progress = , ] [ verbose = false, ] [ downloader = , ] ) -> output url :: AbstractString