And reject paths ending in empty segments.
The following cases were being parsed incorrectly:
- `/` represents the empty path, `~`. This was being parsed into `[~. ~]`
- `/x/` is not valid. This was being parsed into `[~.x ~. ~]`
This happens because `urs:ab` has no problem parsing the empty string.
For some supported cases, like `//x` (`[~. ~.x ~]`), this is actually desired
behavior, but it results in trailing empty segments for paths ending in `/`.
Here we apply a `+sear` on top of the existing parser, that transform the `/`
case to produce `~`, and ensures the absence of a trailing empty segment in
all other cases.
Note that we change `(more fas urs:ab)` to `(most fas urs:ab)`. Since `urs:ab`
parses the empty string, this doesn't actually make a difference, but it does
make it more obvious that the `+rear` call will never crash.
Alternative approaches I attempted all resulted in much more complicated
parser, so the dumb `+sear` seems preferable.
We do eat the performance cost of an additional list traversal (in `+rear`)
with this change, but that is probably not the end of the world.
Fixes#1501.
* Use `rap` to concatenate `cord`s rather than homegrown arm
* Replace `%graph` test fail of association with no-op instead of crash
* Re-style multi-arg runes `:*` `%:` and `:~`
The crunch library and generator are tools to
export group graph data to a CSV-format file.
The purpose of crunch is to help quantify the
growth of the Urbit network.
The code added here is work done under the grant
https://urbit.org/grants/bounties/analytics-script/
