Toml: Clarify line-ending backslash in multi-line strings

[goodmami]

The v1.0.0-rc.1 spec says, regarding multi-line strings:

When the last non-whitespace character on a line is a \, it will be trimmed along with all whitespace (including newlines) up to the next non-whitespace character or closing delimiter. All of the escape sequences that are valid for basic strings are also valid for multi-line basic strings.

This is unclear for the case when that last \ is escaped. I think the ABNF is correct and when I tested with tomlkit it looks good:

>>> from tomlkit import parse
>>> parse(r'''
... ml-escaped-nl = """
...   foo \ 
...   bar \\ 
...   baz \\\ 
...   quux"""''')
{'ml-escaped-nl': '  foo bar \\ \n  baz \\quux'}

But I think the description in the spec can be clearer. I propose the following 1-word change (or 2 if you include the epenthesis of the preceding "a" to "an"):

- ending backslash". When the last non-whitespace character on a line is a `\`, it
+ ending backslash". When the last non-whitespace character on a line is an unescaped `\`, it 

The code snippet above might also be a good test case.

Aside: Is https://github.com/BurntSushi/toml-test the de jure, or even de facto, test set? It hasn't been updated in a while.

[eksortso]

That's a good proposal. Could you open a PR with that change, mentioning #728 in your description?

[eksortso]

Regarding testing, you could ask in #585.

[goodmami]

@eksortso no problem. For the PR, shall I also add the test case to tests/hard_example.toml, which already has some tests about multi-line strings? Or is that what you meant by asking in #585?

[eksortso]

@eksortso no problem. For the PR, shall I also add the test case to tests/hard_example.toml, which already has some tests about multi-line strings?

If it would fit, I'd say yes. I wasn't even thinking about that, but good call.

Or is that what you meant by asking in #585?

You were asking about the state of testing. I wanted to keep that separate, which is why I referred you to #585.

[goodmami]

Great, that's what I thought you meant but just wanted to clarify.

I've just pushed the wording change and made #729.

I noticed that tests/hard_example.toml actually tested a multi-line array, not a multi-line string, but it did have other string tests. Since the test case didn't fit as well as I'd thought, I left it off the initial PR. I can add a commit adding the test, perhaps as a separate test file for strings?

[eksortso]

Your PR looks good to me. Hoping it gets merged soon. @pradyunsg @mojombo Can we merge #729?

[eksortso]

I'm not even sure about test commits, to be honest. Again, read #585 and bring up this particular issue, and ask where tests should go.

[goodmami]

Got it. Thanks!

[pradyunsg]

Gonna go ahead and close this. Let's keep the testing question separate.