Thread overview
writeln and write at CTFE
Jan 13
Andrey
Jan 13
Andrey
Jan 13
z
Jan 13
tsbockman
Jan 13
oddp
Jan 14
tsbockman
January 13
Hello all,
Tell me please how can I "writeln" and "write" in function that is used in CTFE?
At the moment I get this:
> import\std\stdio.d(4952,5): Error: variable impl cannot be modified at compile time

Or may be exist some other ways to do it?
January 13
On Wednesday, 13 January 2021 at 08:35:09 UTC, Andrey wrote:
> Hello all,
> Tell me please how can I "writeln" and "write" in function that is used in CTFE?
> At the moment I get this:
>> import\std\stdio.d(4952,5): Error: variable impl cannot be modified at compile time
>
> Or may be exist some other ways to do it?

pragma(msg, <compile-time-expr>);
January 13
On Wednesday, 13 January 2021 at 09:11:53 UTC, Guillaume Piolat wrote:
> On Wednesday, 13 January 2021 at 08:35:09 UTC, Andrey wrote:
>> Hello all,
>> Tell me please how can I "writeln" and "write" in function that is used in CTFE?
>> At the moment I get this:
>>> import\std\stdio.d(4952,5): Error: variable impl cannot be modified at compile time
>>
>> Or may be exist some other ways to do it?
>
> pragma(msg, <compile-time-expr>);

This may however not do what you wish it to do: https://forum.dlang.org/post/mailman.4526.1499573493.31550.digitalmars-d-learn@puremagic.com

— Bastiaan.
January 13
On Wednesday, 13 January 2021 at 11:31:16 UTC, Bastiaan Veelo wrote:
> On Wednesday, 13 January 2021 at 09:11:53 UTC, Guillaume Piolat wrote:
>> On Wednesday, 13 January 2021 at 08:35:09 UTC, Andrey wrote:
>>> Hello all,
>>> Tell me please how can I "writeln" and "write" in function that is used in CTFE?
>>> At the moment I get this:
>>>> import\std\stdio.d(4952,5): Error: variable impl cannot be modified at compile time
>>>
>>> Or may be exist some other ways to do it?
>>
>> pragma(msg, <compile-time-expr>);
>
> This may however not do what you wish it to do: https://forum.dlang.org/post/mailman.4526.1499573493.31550.digitalmars-d-learn@puremagic.com
>
> — Bastiaan.

Function "ctfeWriteln" doens't exist.

pragma(msg, ...) is used only for CT values.

Today is 2021. Dlang still doesn't have ctfe write functions?
January 13
On Wednesday, 13 January 2021 at 11:50:26 UTC, Andrey wrote:
>
> Function "ctfeWriteln" doens't exist.
>
> pragma(msg, ...) is used only for CT values.
>
> Today is 2021. Dlang still doesn't have ctfe write functions?

Yes.(afaik)
It has shot me on the foot once, to the point i abandoned the idea of ever accomplishing what i wanted to do at compile-time and instead just did it at module construction-time, and i must admit that it was immediately easier to debug.
January 13
On Wednesday, 13 January 2021 at 11:50:26 UTC, Andrey wrote:
> Today is 2021. Dlang still doesn't have ctfe write functions?

You make it sound like D is behind the times. Is CTFE I/O a standard feature in other languages? How many other languages even have a CTFE feature comparable to D's?
January 14
On 13.01.21 21:47, tsbockman via Digitalmars-d-learn wrote:
> Is CTFE I/O a standard feature in other languages? How many other languages even have a CTFE feature comparable to D's?

Just two langs I use from time to time:

1) nim via forced ctfe; way faster than d by running through a vm:

const foo = fib(42)
static:
  echo "foobar"

2) crystal via macros:

{{ puts "foobar" }}

Another one would be zig via comptime, but never tried that.
January 14
On Wednesday, 13 January 2021 at 23:38:54 UTC, oddp wrote:
> Just two langs I use from time to time:
>
> 1) nim via forced ctfe; way faster than d by running through a vm:
>
> const foo = fib(42)
> static:
>   echo "foobar"
>
> 2) crystal via macros:
>
> {{ puts "foobar" }}
>
> Another one would be zig via comptime, but never tried that.

Good to know... doesn't sound like it's some kind of standard "2021" feature, though. Those are all lesser-known languages (like D), not industry standard stuff like C++, Java, etc.