This includes a generic JSONStream library built on top of Text.JSON
(somewhat hackishly).
It would be possible to stream out a single json document describing
all actions, but it's probably better for consumers if they can expect
one json document per line, so I did it that way instead.
Output from external programs used for transferring files is not
currently hidden when outputting json, which probably makes it not very
useful there. This may be dealt with if there is demand for json
output for --get or --move to be parsable.
The version, status, and find subcommands have hand-crafted output and
don't do json. The whereis subcommand needs to be modified to produce
useful json.
Using a single strictness annotation, in just the right place.
Tried several others, none of which helped and some of which potentially
hurt. This is only the second time I've really had to deal with this in
a year of using haskell, which is, I suppose not that bad.
Statting files returned by dirContents to see if they exist and are regular
files seems pretty useless. This code was originally part of fsck, and
perhaps the idea then was to avoid things returned by dirContents that were
not files. But it's certianly not needed in the current use cases for
getKeysPresent.
Backends are now only used to generate keys (and check them); they
are not arbitrary key-value stores for data, because it turned out such
a store is better modeled as a special remote. Updated docs to not
imply backends do more than they do now.
Sometimes I'm tempted to rename "backend" to "keytype" or something,
which would really be more clear. But it would be an annoying transition
for users, with annex.backends etc.