Bragging about Unix and D

[Tom S]

Georg Wrede wrote:
> What I tried to do was some kind of template magic (a la Don) that 
> prints something like this at compile time, without even creating an 
> executable.
> 
> -- Sigh, can't win 'em all.

Not hard at all...



const int numWidth = 6;
const int width   = 10;
const int height  = 10;


template itoa(int i) {
	static if (i < 10) {
		const char[] itoa = "" ~ "0123456789"[i];
	} else {
		const char[] itoa = itoa!(i/10) ~ "0123456789"[i%10];
	}
}


template nspaces(int n) {
	static if (n > 0) {
		const char[] nspaces = " " ~ nspaces!(n - 1);
	} else {
		const char[] nspaces = "";
	}
}


template itoa_pad(int i) {
	const char[] itoa_pad = itoa!(i) ~ nspaces!(numWidth - itoa!(i).length);
}


template row(int hpos, int i = 0) {
	static if (i+1 < width) {
		const char[] row = itoa_pad!(i*hpos) ~ row!(hpos, i+1);
	} else {
		const char[] row = itoa_pad!(i*hpos);
	}
}


template table(int i = 0) {
	pragma (msg, row!(i));

	static if (i+1 < height) {
		mixin .table!(i+1) table;
	} else {
		alias void table;
	}
}


alias table!() draw;



--
Tomasz Stachowiak