Support interpolating in git cmd string macro

[fredrikekre]

No description provided.

[DilumAluthge]

I think this is a bug in Julia?

julia> macro foo_cmd(ex)
       println(ex)
       end
@foo_cmd (macro with 1 method)

julia> a = "123"
"123"

julia> foo`x y z`
x y z

julia> foo`x $a z`
x $a z

[DilumAluthge]

julia> macro foo_str(ex)
       println(ex)
       end
@foo_str (macro with 1 method)

julia> macro bar_cmd(ex)
       println(ex)
       end
@bar_cmd (macro with 1 method)

julia> a = "hello"
"hello"

julia> foo"$a"
$a

julia> bar`$a`
$a

[DilumAluthge]

JuliaLang/julia#23481

[DilumAluthge]

The discussion in JuliaLang/julia#23481 seems to imply that support for interpolation string macros won’t be added to Julia.

So we’d have to add the support ourselves in this package.

[fredrikekre]

So we’d have to add the support ourselves in this package.

Yea, thats what I meant from the start, should have been more clear.

[DilumAluthge]

So we’d have to add the support ourselves in this package.

Yea, thats what I meant from the start, should have been more clear.

Nah, the confusion was all on me.

Anyway, sounds like a good idea. I don’t really know enough about macros to figure out how to don’t this; maybe someone else can help out.

[fredrikekre]

I haven't looked at it, but can maybe look at what @btime etc does since they also use $ in macros to men interpolation (although for a different purpose).

[omus]

I had to deal with handling interpolation in a non-standard string literal here: https://github.com/invenia/MultilineStrings.jl/blob/3192dbf8872b99cb2a09a46894b22428191805ca/src/MultilineStrings.jl#L120. I think the same approach would probably work here

[GunnarFarneback]

I propose to deprecate the cmd string macro in favor of git("clone https://github.com/JuliaRegistries/General") and split the argument with Base.shell_split. This gives interpolation for free and allows the use of whatever string macros people want to use. (I already have a PR in preparation for git(::AbstractString)).

[fredrikekre]

Isn't it better to just let people use

git = Git.git()
`$git clone ....`

?

[GunnarFarneback]

That's already available so if we think that's all that's needed the easiest solution is just to remove the cmd macro.

[fredrikekre]

Exactly. Is there any other advantage with the cmd macro?

[GunnarFarneback]

Considering that it currently does a plain split of the argument I would say that it's mostly kinda dangerous but for one time uses it's a bit more compact than first having to create the git object or interpolating it into the command. My proposal would allow things like git(raw"status src\foo\bar.jl") which might be practical if you e.g. need to copy/paste paths on Windows. Never mind, shell_split destroys the backslashes.

The functionality I really want, however, is git(["status", "README.md"]) to bypass the cmd argument parsing. But maybe the magic of the cmd interpolation of iterables doesn't make it worth the trouble.

[DilumAluthge]

It sounds like the plan here would be:

1. Remove the @git_cmd cmd macro. We can do this in a nonbreaking release because it's not part of the public API.
2. Add a new method git(::AbstractVector(<:AbstractString)) for the use case that @GunnarFarneback wants.

[DilumAluthge]

Step 1 is done in #34