Rewrite parser more readable, little faster

[unix1]

@benoitc let me know if you are open to this kind of parser rewrite. Some notes:

• marginal performance improvement, around 10%
• more readable (I think, unless you don't like regex)
• couldn't get multiline values to work in existing implementation, so I left it out (I can add it if needed)
• passes all current tests
• possible further speed improvements with compiled regex

Please let me know your thoughts.

[unix1]

@benoitc thumbs up/down - making things better, or uninteresting? Please let me know when you get a chance.

[benoitc]

@unix1 sorry I missed this change.... will have a look later in the day.

[unix1]

@benoitc, any luck? Feedback? I'm all ears.

[unix1]

@benoitc ping?

[benoitc]

I completely forgot that change... Sorry for that ... I will look at it now.

[benoitc]

more than one year later... Sorry for that... Just if you remember, can you tell me what you meant by couldn't get multiline values to work in existing implementation, so I left it out (I can add it if needed)? Is this something missing in current master ?

[benoitc]

@unix1 i guess i see the point. I tested your implementation and it mostly worked. See comments. I know it's a little late to ask, but in case of what was your idea to add support for multilines values?

[benoitc]

the case where there are no sections in the file should be handled here. It's useful when you need to pass a local file that will contains the updates.

[unix1]

@benoitc thanks for looking and providing feedback. I'll probably have time to look at this this weekend.

As for multiline values, I remember I couldn't find a standard way of doing it (people do it their own ways when they think they need it, and current master didn't support it) - that's why I didn't put it in. I don't have a use case; unless you have one, I don't think it should be there.

In the hypothetical future where it's needed, we could say:

any config value that ends with a backslash continues on next line:

[letter]
message = Hello,\
          This is a message\
          Bye
from = Foo

or any non-config non-section non-comment non-empty line:

[letter]
message = Hello,
          This is a message
          Bye
from = Foo

But it gets ugly fast; and again, unless you have a use case, I'd keep it out for now.