Range format specifiers in other languages?

[H. S. Teoh]

On Mon, Oct 12, 2020 at 05:51:21AM +0000, Imperatorn via Digitalmars-d-learn wrote:
> On Monday, 12 October 2020 at 00:59:33 UTC, Adam D. Ruppe wrote:
> > On Monday, 12 October 2020 at 00:46:37 UTC, Imperatorn wrote:
> > > To people trying to learn, why is that % before ( needed in the
> > > format string?
> > 
> > The %( ... %) stuff is expanded and repeated for each element inside
> > the given array.
> 
> Thanks, it seems there are some pretty powerful formatting options:
> 
> https://dlang.org/phobos/std_format.html

Indeed.

%(...%) is one of my favorite because it can be nested, so it's a very
useful quick-n-dirty tool for debugging ranges. With .chunks and .map,
you can format just about any range-based data in a one-liner for
dumping debug info.

Another cool one is the `,` digit-grouper:

	import std;
	void main() {
		writefln("%,2d", 1234567890);
		writefln("%,3d", 1234567890);
		writefln("%,4d", 1234567890);
		writefln("%,3?d", '_', 1234567890);
		writefln("%,4?d", '\'', 1234567890);
		writefln("%,4?.2f", '\'', 1234567890.123);
	}

Output:
	12,34,56,78,90
	1,234,567,890
	12,3456,7890
	1_234_567_890
	12'3456'7890
	12'3456'7890.12


T

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