String literal without interpolation

[Jonathan Malmaud]

Is there a string prefix that results in no $ interpolation? Like 

@assert raw"$x"[1] == "$"

[Stefan Karpinski]

There used to be, but it was deleted. I think that many people want it back.

[Stefan Karpinski]

There's still a vestigial definition of an L_str macro in base/base.jl, but it isn't exported or used anywhere. But I don't really think the L"..." form had ideal behavior anyway. It really ought to at least unescape backslashes.

[Jonathan Malmaud]

Thanks, I'll open a feature request.

[Steven G. Johnson]

String macros in general treat everything literally, as Stefan alluded to. I use this in PyPlot to define an L"..." macro for LaTeX. In that context, is is important not to escape backslashes either, so that you can do e.g. L"blah $\sqrt{\alpha}$"

[Stefan Karpinski]

Right, what I actually meant was removing backslashes when they occur in the input before your quote string (double quote, typically). But I actually think we're already doing this:

julia> macro L_str(s)

         s

       end

julia> L"\""

"\""

julia> L"foo\"\x"

"foo\"\\x"

julia> print(L"foo\"\x")

foo"\x

The backslash before the " disappears while the backslash before the x does not. However, that means that you can't, e.g. pass to a string macro a string ending with a single backslash:

julia> print(L"foo\\")

foo\\

[Scott Jones]

I would say that is a bug... that `\\` doesn't become `\`.

[Stefan Karpinski]

This syntax doesn't exist anymore – bug fixed.