使用方括号输出数组元素

Question

此代码创建一个记录变量 (r) 和一个包含多个数组的元组变量 (t) 并将它们打印到标准输出：

const N = 5;

record Myrec {
    var a: [1..N] int = (for i in 1..N do i);
    var b: [1..N] int = (for i in 1..N do i);
    var c: [1..N] int = (for i in 1..N do i);
}

proc test() {
    var r: Myrec;
    var t = (r.a, r.b, r.c);
    writeln( "r = ", r );
    writeln( "t = ", t );
}

test();

如果我运行这个代码，我得到这个输出：

r = (a = 1 2 3 4 5, b = 1 2 3 4 5, c = 1 2 3 4 5)
t = (1 2 3 4 5, 1 2 3 4 5, 1 2 3 4 5)

但我觉得输出不是很可读（特别是在 t 的情况下）。所以，我想知道是否有某种方法可以用方括号打印此类变量，例如，如下所示？

t = ([1 2 3 4 5], [1 2 3 4 5], [1 2 3 4 5])

我认为可以通过使用 writef() + 格式字符串 + 传递元组的每个字段（或为此目的编写一个特定的函数）来实现，但如果有一些方便的话会很好实现类似目标的方法...

Answer 1

根据 FormattedIO 的文档，格式字符串 %ht（或 %jt）似乎完成了为数组元素添加 [...] 的工作。下面附上修改后的示例代码：

record Myrec {
    var n = 100;
    var a = [1,2,3];
    var x = 1.23;
}

proc test() {
    var r: Myrec;
    var t = (r.a, r.a);

    writeln();
    writeln( "r = ", r );
    writef( "r = %ht\n", r );  // "h" -> Chapel style
    writef( "r = %jt\n", r );  // "j" -> JSON style

    writeln();
    writeln( "t = ", t );
    writef( "t = %ht\n", t );

    var arr2d: [1..2, 1..3] int = (for i in 1..6 do i);

    writeln();
    writeln( "arr2d =\n", arr2d );
    writef( "arr2d =\n%ht\n", arr2d );
}

test();

输出

r = (n = 100, a = 1 2 3, x = 1.23)
r = new Myrec(n = 100, a = [1, 2, 3], x = 1.230000e+00)
r = {"n":100, "a":[1, 2, 3], "x":1.230000e+00}

t = (1 2 3, 1 2 3)
t = ([1, 2, 3], [1, 2, 3])

arr2d =
1 2 3
4 5 6
arr2d =
[
 [1, 2, 3],
 [4, 5, 6]
]

使用方括号输出数组元素

Using square brackets for the output of array elements

format

output

chapel