On Wednesday, 25 December 2013 at 21:23:23 UTC, Philippe Sigaud
wrote:
I'll consider that as a D grammar question, and not a
Pegged-specific
question, since Pegged just uses a copy of the D site grammar
:-)
Thank you regardless. I'll be sure to submit some issues once
we're a bit further down the road. Error handling is what has
displeased me the most so far, with only a single test case ever
displaying something useful. I'm not sure what the solution
should be though, perhaps the matches that munched the most
tokens before failing?
Also, it should be possible to detect non-munching cycles aka.
left recursion without too much extra compile time. It's funny
because it's fine on compile time, but instant death at runtime.
I'll post some of that once we're further.
On Wednesday, 25 December 2013 at 22:28:06 UTC, Timon Gehr wrote:
The following is a parse tree for char* format:
snip
Oooh, I missed that. I didn't think it possible one would dissect
it like that. In my mind it would make more sense to keep char
and * together, since it's a type of its own. Interesting. And
weird.
I consider the grammar specification (as well as some details
of what is valid syntax) to be quite inelegant, unnecessarily
repetitive and inconvenient for parser generators, but I am not
sure if a clean-up would be welcome.
I'm not sure. I haven't imported too much yet, but the only thing
I've had to work around was left recursion in some arithmetic
expressions (add and mul I believe). It's complicated for sure,
but the language specification has survived nearly intact. My
only past experience is the toy language Tiger made for education
and stories I've been told of "normal" language specifications
being really awful. So some copy paste is nice for a change.
I'd still like a look at a "clean" grammar if anyone has one
around.
