run.dlang.io - a modern way to run D code

[H. S. Teoh]

On Wed, Dec 13, 2017 at 04:59:00PM -0800, H. S. Teoh via Digitalmars-d-announce wrote:
[...]
> Sadly, `dmd - -run` currently doesn't quite work just yet. I should look
> into fixing that.  And *then* we wouldn't need to invent a temporary
> filename for the executable in our keybinding.
[...]

Turns out, the code change to make this happen is trivial:

	https://github.com/dlang/dmd/pull/7435

With this PR, you can compile and run code in standard input without
needing to specify any filenames:

$ echo 'import std.stdio; void main() { writeln("Hello, World!"); }' | dmd -run -
Hello, World!
$

Of course, piping the output of `echo` to dmd isn't a big deal. A more
interesting use case is being able to pipe the contents of an editor
buffer to dmd as input, and instantly receiving the program output in
the editor.

For example, I can open a new window in Vim (no filename), and type in
the following contents:

------
import std.stdio;
void main() {
	writeln("Instant win!");
}
------

Then type:

	:0,$!dmd -run -

and the buffer contents are now:

------
Instant win!
------

(In English, the vim magic word above means:
	:		Enter command mode
	0,$		Take the range of lines from 0 to the end of file
	!		And filter these lines by a shell command
	dmd -run -	The command to run
)

This can, of course, be bound to a custom keybinding, then you'll have
your one-stop shop for compiling D snippets without ever seeing (much
less typing) any temporary filenames. And without needing an internet
connection.

Instant win!  :-P


T

-- 
When solving a problem, take care that you do not become part of the problem.