add subdir functionality

[KristofferC]

julia> Pkg.add(PackageSpec(path="MainRepo", subdir="SubDir.jl"))
  Updating git-repo `/home/kc/Documents/JuliaTests/MainRepo`
 Resolving package versions...
  Updating `~/Pkg.jl/Project.toml`
  [900e8cb0] + SubDir v0.1.0 #master (/home/kc/Documents/JuliaTests/MainRepo[/SubDir.jl])
  Updating `~/Pkg.jl/Manifest.toml`
  [900e8cb0] + SubDir v0.1.0 #master (/home/kc/Documents/JuliaTests/MainRepo[/SubDir.jl])

[codecov]

Codecov Report

Merging #1422 into master will decrease coverage by 27.33%.
The diff coverage is 79.75%.

@@             Coverage Diff             @@
##           master    #1422       +/-   ##
===========================================
- Coverage   87.29%   59.95%   -27.34%     
===========================================
  Files          25       25               
  Lines        5445     5396       -49     
===========================================
- Hits         4753     3235     -1518     
- Misses        692     2161     +1469

Impacted Files	Coverage Δ
src/Display.jl	80.46% <ø> (-12.5%)	⬇️
src/GitTools.jl	86.33% <100%> (-6.7%)	⬇️
src/manifest.jl	89.51% <100%> (+0.17%)	⬆️
src/Types.jl	75.76% <75.83%> (-7.55%)	⬇️
src/Operations.jl	83.96% <83.33%> (-8.26%)	⬇️
src/API.jl	81.43% <88.88%> (-13.07%)	⬇️
src/Artifacts.jl	0% <0%> (-91.61%)	⬇️
src/BinaryPlatforms.jl	0.37% <0%> (-91.43%)	⬇️
src/Resolve/maxsum.jl	0% <0%> (-90.1%)	⬇️
src/REPLMode/completions.jl	0% <0%> (-86.96%)	⬇️
... and 17 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 53b3580...356dd7f. Read the comment docs.

[fingolfin]

This is something we are rather interested in and would love to have.

However, it seems this PR has stalled for now. I was wondering if there is any interest in / need for help from outsiders? I may have some time in a few weeks to dig into this, but obviously I don't want to step on any toes or waste time in case somebody is actually working on this elsewhere, or perhaps there are reasons for the stall (e.g. perhaps problems where discovered with the approach, or further design discussions are needed, or ...)

Anyway, just wanted to say I'd be interested in chipping in, but of course I understand you guys may have other priorities.

[KristofferC]

IIRC, this PR was pretty much done, with the exception of the Pkg REPL implementation of it, and bashing my head against

Pkg.jl/src/REPLMode/argument_parsers.jl

Line 21 in 54eae6c

r"((git|ssh|http(s)?)|(git@[\w\-\.]+))(:(//)?)([\w\.@\:/\-~]+)(\.git)(/)? | [^@\#\s]+\s*=\s*[^@\#\s]+ | \#\s*[^@\#\s]* | @\s*[^@\#\s]* | [^@\#\s]+"x

made me kind of lose my interest in the whole thing.

I do think we could just punt on supporting this from the REPL though.

Help to get this rebased and a bit more tested would be appreciated because I think it is a good feature to have.

[KristofferC]

I rebased this, should be good to go. It doesn't include any REPL syntax but that can be added later.

[fingolfin]

Thank you so much! Looks pretty good to me. I am an outsider, but since I am excited about this feature, I had a look at the changes, and found them quite clean and pleasant to read. I left a few comments, which of course you are completely free to ignore.
Thanks again!

[fingolfin]

Nice detail!