- From: Amelia Bellamy-Royds <amelia.bellamy.royds@gmail.com>
- Date: Fri, 6 Feb 2015 17:19:28 -0700
- To: Juergen Roethig <roethig@dhbw-karlsruhe.de>
- Cc: www-svg <www-svg@w3.org>
- Message-ID: <CAFDDJ7x7PadHzqpt2F6809rRfmgrH-JczVUMt7CdVy+AifmOqg@mail.gmail.com>
I have to say that I agree with Juergen in the general case, when he writes consistency with other cases is always a good argument for a change. But in > this case, I would have proposed to have a consistency to a notation which > is _readable_, and _intuitively_ _understandable_ by _humans_ instead of > allowing notations like "1.5.3-1,.2-.7e1.2.3" in any case I definitely don't like the idea of encouraging people to smoosh all their numbers together. For one thing, it makes writing regular expressions to parse values from scripts a serious pain. (P.S. On that particular jumble of numbers, I was wrong -- the specs clearly say that an exponent must be an integer. But it does prove Juergen's point!) However, I do like the idea of inter-consistency between polygon and path. As Cameron notes, many implementations already support the condensed form -- probably because they are using the same path parsing code to handle polygons and polylines. I suggest something like the following language: Authors and authoring agents SHOULD use a comma or whitespace or both to separate values in a <list-of-numbers> or <number-optional-number> datatype. User agents MAY ignore errors from missing separators where the value can still be parsed as distinct numbers according to the grammar in the [Basic Data Types section]. (In other words, formalize the current situation.) OR replace the "MAY" by "SHOULD" in the second sentence (i.e., encourage *all* browsers, etc., to adopt the permissive behavior). However, there's also a counter argument: This approach will sometimes cause very-difficult-to-debug errors if the author (or their script) has put together a string of numbers that can be correctly parsed as numbers -- just not the numbers the author intended. For example, my -.7e1.2 error. If separation is always required between subsequent numbers, drawing of the shape would stop right at that erroneous coordinate, and I can easily track down the problem. If separation is not required, that gets parsed as two numbers (-0.7e1 and 0.2), and drawing continues, but now all my coordinate pairs are jumbled up, creating a total mess until it reaches the end of the list of points and there's an extra number left at the end. But the entire shape would be a mess and it would be hard to figure out what was going wrong. AmeliaBR
Received on Saturday, 7 February 2015 00:19:56 UTC