Re: Bug in grammar for paths

These quirks of the path grammar are used by SVG minimizers/optimizers, so
they can't be changed now.  Content relies on the fact that 4-3.1.3e2.4 is
four separate numbers (equivalent to 4, -3.1, 0.3e2, 0.4).

Yes, it does require a more complex parser.  You can't just split the
string on separators, you need to scan through it character by character,
matching the sequence as defined, using a greedy algorithm.  A number is as
many characters as make sense in a number, in order, and no more.

Jirka Kosek wrote:

> Seems that grammar is only illustrational because there are other issues
> with it -- for example grammar accepts only integers not decimal numbers.


This was an error from when SVG 2 was edited to add the Bearing command and
convert from BNF to EBNF.  There is an open issue, I didn't realize that it
never got fixed:  https://github.com/w3c/svgwg/issues/286

The SVG 1.1 definition of a "number" is correct (
https://www.w3.org/TR/SVG11/paths.html#PathDataBNF). Decimals and
scientific notation are allowed.

If anyone wants to make a pull request on SVG 2 to fix it, that would be
appreciated. We can at least change it in the Editor's Draft, although I
don't know when the TR spec will be re-published.

~ABR