Relax q"EOS strings

[Bolpat]

Currently, Identifier-delimited strings must have the closing delimiter on the first line. That looks awful in code. C# has """ strings that are either in-line or multi-line, and the multi-lines have the property that the indentation of the closing """ is subtracted from every line of the literal. D could do the same with its Identifier-delimited strings.

// current D code
void f()
{
    auto xs = q"EOS
TODO
  - propose another string literal
EOS";
}

// equivalent C# code
void F()
{
    var xs = """
    TODO
      - propose another string literal
    """;
    // or, alternatively:
    var xs = """
        TODO
          - propose another string literal
        """;
}

// proposed D code
void f()
{
    auto xs = q"EOS
    TODO
      - propose another string literal
    EOS";
}

Technically, that is a breaking change, as EOS" may occur inside the literal (just not at the beginning of a line), but probably two things are true about current D code:

• q"EOS strings are rare.
• The few q"EOS strings that do exist don’t have EOS anywhere in the string content, let alone EOS".

The fix is trivial: Use another identifier.

[ZILtoid1991]

I think a single q"{ ... }" is enough for 99% of applications. My updated SDL specs added this kind of string under the name "scoped string", and the parser only checks for a single }" at the end, and does not do any scope counting.

[Bolpat]

I think a single q"{ ... }" is enough for 99% of applications.

You’re missing the point. The point is about indentation.

void main()
{
	import std.stdio;
	writeln([q"{
		Hello D
	}"]);
}

This prints ["\n\t\tHello D\n\t"]. What I want is: ["\tHello D"]. (I’m using [] so writeln prints escape sequences.)