This hand-rolled wonder of switch statements is capable of parsing a 5
byte document in less than a gigasecond.
This was an interesting exercise in writing a non-recursive parser for
a nested structure format. There's a lot of very slightly different
repetition, which I'm not wild about, but it can handle deeply nested
documents. I tested with a 50 mb indented list tree document (10_000
lines of nesting) and a ReleaseFast build was able to parse it in
approximately 50 ms with a peak memory footprint of about 100 MB (of
which, half was the contents of the document itself, as the file is
read into a single allocated buffer that does not get freed until
program exit). I don't consider myself to be someone who writes high
performance software, but I think those results are quite acceptable,
and I doubt any recursive implementation would even be able to parse
that document at all (the python NestedText implementation smashes
directly into a RecursionError, unsurprisingly).
Anyway, let's call this a success. I will actually probably export this
to a separate project soon. The main problem is coming up with a name.
I also strongly suspect there are some lurking bugs still, and I think
I do want to add nested inline map/list support (and also parsing
directly into objects).
