Multi-line strings are handy, but I have a small problem.

This is an example, it has a problem, there is an unwanted newline at the beginning:

writeln("
- First item:  150
- Second item: 200
- Third item:  105");


To avoid it you can write this, but both break the alignment in the source code, and it's not nice looking:

writeln("- First item:  150
- Second item: 200
- Third item:  105");


writeln(
"- First item:  150
- Second item: 200
- Third item:  105");


To solve this problem in Python you are allowed to write (in Python you need tree " or tree ' to denote a multi-line string):

print """\
- First item:  150
- Second item: 200
- Third item:  105"""


The extra slash at the beginning avoids the start newline.

Is this currently possible in D too? If this isn't possible, is it worth a very little enhancement request for the support of that syntax?

Bye,
bearophile

"bearophile" <bearophileHUGS@lycos.com> wrote in message news:j0ac3m$29hj$1@digitalmars.com...
> Multi-line strings are handy, but I have a small problem.
>
> This is an example, it has a problem, there is an unwanted newline at the beginning:
>
> writeln("
> - First item:  150
> - Second item: 200
> - Third item:  105");
>
>
> To avoid it you can write this, but both break the alignment in the source code, and it's not nice looking:
>
> writeln("- First item:  150
> - Second item: 200
> - Third item:  105");
>
>
> writeln(
> "- First item:  150
> - Second item: 200
> - Third item:  105");
>
>
> To solve this problem in Python you are allowed to write (in Python you need tree " or tree ' to denote a multi-line string):
>
> print """\
> - First item:  150
> - Second item: 200
> - Third item:  105"""
>
>
> The extra slash at the beginning avoids the start newline.
>
> Is this currently possible in D too? If this isn't possible, is it worth a very little enhancement request for the support of that syntax?
>

It's even worse with indentation:

void foo()
{
    if(blah)
    {
        writeln("- First item:  150
            - Second item: 200
                -- Subitem 1
                -- Subitem 2
            - Third item:  105");
    }
}

That's why I created a (CTFEable) fucntion normalize() (maybe could use a better name?):

http://www.dsource.org/projects/semitwist/browser/trunk/src/semitwist/util/text.d#L630

void foo()
{
    if(blah)
    {
        // Works properly:
        writeln("- First item:  150
            - Second item: 200
                -- Subitem 1
                -- Subitem 2
            - Third item:  105".normalize());
    }
}

Another example:

Do this:
--------------------
void foo()
{
    enum codeStr = q{
        // Written in the D Programming Langauge
        // by John Doe

        int main()
        {
            return 0;
        }
    }.normalize();
}
--------------------

Instead of this:
--------------------
void foo()
{
enum codeStr =
q{// Written in the D Programming Langauge
// by John Doe

int main()
{
    return 0;
}};
}
--------------------

The resulting string is exactly the same.

I'd be happy to work it into something appropriate for Phobos if people are intersted.

    writeln(q"EOS
- First item:  150
- Second item: 200
- Third item:  105
EOS");

You can replace EOS with whatever you want.

Andrej Mitrovic:

>     writeln(q"EOS
> - First item:  150
> - Second item: 200
> - Third item:  105
> EOS");
> 
> You can replace EOS with whatever you want.

It seems to add a newline at the end :-(

Bye,
bearophile

This is the best I can do:

writeln(
`- First item:  150
- Second item: 200
- Third item:  105`);

Hope OCD doesn't kick in! :p

if you can, use write instead of writeln

             write(q"EOS
- First item:  150
- Second item: 200
- Third item:  105
EOS");

Followed by stdout.flush(); to be sure.

got one extra line, I meant

               write(q"EOS
- First item:  150
- Second item: 200
- Third item:  105
EOS");

On 22.07.2011 3:18, bearophile wrote:
> Multi-line strings are handy, but I have a small problem.
>
> This is an example, it has a problem, there is an unwanted newline at the beginning:
>
> writeln("
> - First item:  150
> - Second item: 200
> - Third item:  105");
>
>
> To avoid it you can write this, but both break the alignment in the source code, and it's not nice looking:
>
> writeln("- First item:  150
> - Second item: 200
> - Third item:  105");
>
>
> writeln(
> "- First item:  150
> - Second item: 200
> - Third item:  105");
>
>
> To solve this problem in Python you are allowed to write (in Python you need tree " or tree ' to denote a multi-line string):
>
> print """\
> - First item:  150
> - Second item: 200
> - Third item:  105"""
>
>
> The extra slash at the beginning avoids the start newline.
>
> Is this currently possible in D too? If this isn't possible, is it worth a very little enhancement request for the support of that syntax?
>
> Bye,
> bearophile
How about:

writeln(
"- First item:  150\n"
"- Second item: 200\n"
"- Third item:  105");

Yeah, I know implicit concatenation is bad and I would agree once ~ concatenate complie-time string for 0 overhead.
After all, hardcoded strings are not exactly good thing in the first place.
For big formatted texts just use string import :
     writeln(import("usage.txt"));
work like a charm.
So IMHO it's a non-issue.

-- 
Dmitry Olshansky

Dmitry Olshansky:

> writeln(
> "- First item:  150\n"
> "- Second item: 200\n"
> "- Third item:  105");
> 
> Yeah, I know implicit concatenation is bad and I would agree once ~ concatenate complie-time string for 0 overhead.

This works, but it's noisy. Multi-line strings are present in D right to avoid this.


> After all, hardcoded strings are not exactly good thing in the first place.

They are frequently needed in little programs, like script-like programs. I expect D to be good enough for such kind of programs too.


> For big formatted texts just use string import :
>       writeln(import("usage.txt"));
> work like a charm.
> So IMHO it's a non-issue.

I agree it's not a necessary thing, just like multi-line strings are not necessary. But it's handy, and none of the solutions shown in this tread is very good. So I've added an enhancement request:
http://d.puremagic.com/issues/show_bug.cgi?id=6361

Thank you for the answers and comments,
bye,
bearophile