finally Clauses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 9.6 Tasks (aka Coroutines) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . regardless of how it exits. For example, here is how we can guarantee that an opened file is closed: 9.6. TASKS (AKA COROUTINES) 93 f = open("file") try # operate on file f finally close(f) end When and finally as well. In this case the finally block will run after catch has handled the error. 9.6 Tasks (aka Coroutines) Tasks are a control flow feature that allows computations to be suspended and

finally Clauses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 9.6 Tasks (aka Coroutines) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . regardless of how it exits. For example, here is how we can guarantee that an opened file is closed: 9.6. TASKS (AKA COROUTINES) 93 f = open("file") try # operate on file f finally close(f) end When and finally as well. In this case the finally block will run after catch has handled the error. 9.6 Tasks (aka Coroutines) Tasks are a control flow feature that allows computations to be suspended and

finally Clauses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 9.6 Tasks (aka Coroutines) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . well. In this case the finally block will run after catch has handled the error. 9.6. TASKS (AKA COROUTINES) 93 9.6 Tasks (aka Coroutines) Tasks are a control flow feature that allows computations to

finally Clauses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 9.6 Tasks (aka Coroutines) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . regardless of how it exits. For example, here is how we can guarantee that an opened file is closed: 9.6. TASKS (AKA COROUTINES) 93 f = open("file") try # operate on file f finally close(f) end When and finally as well. In this case the finally block will run after catch has handled the error. 9.6 Tasks (aka Coroutines) Tasks are a control flow feature that allows computations to be suspended and

匿名函数 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 9.6 元组 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Array{Float64,1}: 1.0 4.0 2.0 如果做为第一个参数传递给 map 的转换函数已经存在，那直接使用函数名称是没问题的。但是通常 要使用的函数还没有定义好，这样使用匿名函数就更加方便： 9.6. 元组 71 julia> map(x -> x^2 + 2x - 1, [1, 3, -1]) 3-element Array{Int64,1}: 2 14 -2 接受多个参数的匿名函数写法可以使用语法 a 0-argument anonymous function that is called only when the requested key is absent from dict. 9.6 元组 Julia 有一个和函数参数与返回值密切相关的内置数据结构叫做元组（tuple）。一个元组是一个固定长 度的容器，可以容纳任何值，但不可以被修改 (是 immutable 的)。元组通过圆括号和逗号来构造，其

finally Clauses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 9.6 Tasks (aka Coroutines) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . and finally as well. In this case the finally block will run after catch has handled the error. 9.6 Tasks (aka Coroutines) Tasks are a control flow feature that allows computations to be suspended and

Exception Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 9.6 Tasks (aka Coroutines) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . and finally as well. In this case the finally block will run after catch has handled the error. 9.6 Tasks (aka Coroutines) Tasks are a control flow feature that allows computations to be suspended and

Exception Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 9.6 Tasks (aka Coroutines) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . and finally as well. In this case the finally block will run after catch has handled the error. 9.6 Tasks (aka Coroutines) Tasks are a control flow feature that allows computations to be suspended and

Exception Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 9.6 Tasks (aka Coroutines) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . and finally as well. In this case the finally block will run after catch has handled the error. 9.6 Tasks (aka Coroutines) Tasks are a control flow feature that allows computations to be suspended and

finally Clauses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 9.6 Tasks (aka Coroutines) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . and finally as well. In this case the finally block will run after catch has handled the error. 9.6 Tasks (aka Coroutines) Tasks are a control flow feature that allows computations to be suspended and