Quote and escape strings with repr

[mirkobunse]

This PR directly follows from the discussion in #90

[codecov]

Codecov Report

Merging #91 into master will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master      #91      +/-   ##
==========================================
- Coverage   80.88%   80.85%   -0.03%     
==========================================
  Files          12       12              
  Lines        1454     1452       -2     
==========================================
- Hits         1176     1174       -2     
  Misses        278      278              

Impacted Files	Coverage Δ
src/writer.jl	97.61% <ø> (-0.11%)	⬇️

---

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 bf30a3d...febbbc4. Read the comment docs.

[christopher-dG]

I think this does fix the issue but it also means that we lose multiline strings, which can be very useful.

On YAML 0.4.2:

julia> println(YAML.write(Dict("foo" => """{\n  "pretty": "json"\n}""")))
foo: |
    {
      "pretty": "json"
    }

Personally I would suggest the following:

a: "plain string"
b: "with a trailing newline, the string is no less readable\n"
c: |
  with
  multiple
  lines
d: |
  with "quotes" inside it
e: |
  with tricky \ backslashes

[mirkobunse]

Thanks for your comment!

I agree, actual multi-line strings would be a nice feature. However, I can also imagine that some users actually prefer the single-line fully-escaped solution (or do not care), e.g. when their gut feeling about property c was that a single line is more concise. In the long run, we should provide an argument newlines (or similar) to make the user choose how to handle them. We should then set the default to the behavior you proposed.

My intention behind this PR is to make YAML.write work in the first place. We can handle style in another PR.

[christopher-dG]

I'm happy to make another PR to handle style. Reason being I'm using YAML for saving HTTP response bodies which are often pretty-printed JSON.

[kescobo]

Is there any reason anyone can see to not merge this - looks good to me (but I jumped the gun last time...)

[christopher-dG]

I'm pretty sure this should be bulletproof, if not aesthetically pleasing 😄

[kescobo]

Good enough for me!