added preferred-content log, and allow editing it with vicfg

This includes a full parser for the boolean expressions in the log,
that compiles them into Matchers. Those matchers are not used yet.

A complication is that matching against an expression should never
crash git-annex with an error. Instead, vicfg checks that the expressions
parse. If a bad expression (or an expression understood by some future
git-annex version) gets into the log, it'll be ignored.

Most of the code in Limit couldn't fail anyway, but I did have to make
limitCopies check its parameter first, and return an error if it's bad,
rather than erroring at runtime.
This commit is contained in:
Joey Hess 2012-10-04 15:48:59 -04:00
parent c809f3d486
commit bc649a35ba
9 changed files with 193 additions and 33 deletions

View file

@ -42,11 +42,15 @@ firstLine = takeWhile (/= '\n')
{- Splits a list into segments that are delimited by items matching
- a predicate. (The delimiters are not included in the segments.) -}
segment :: (a -> Bool) -> [a] -> [[a]]
segment p l = map reverse $ go [] [] l
segment p = filter (not . all p) . segmentDelim p
{- Includes the delimiters as segments of their own. -}
segmentDelim :: (a -> Bool) -> [a] -> [[a]]
segmentDelim p l = map reverse $ go [] [] l
where
go c r [] = reverse $ c:r
go c r (i:is)
| p i = go [] (c:r) is
| p i = go [] ([i]:c:r) is
| otherwise = go (i:c) r is
{- Given two orderings, returns the second if the first is EQ and returns