darcs-beta- a distributed, interactive, smart revision control system




data Hopefully a Source

Hopefully p C (x y) is Either String (p C (x y)) in a form adapted to darcs patches. The C (x y) represents the type witness for the patch that should be there. The Hopefully type just tells whether we expect the patch to be hashed or not, and SimpleHopefully does the real work of emulating Either. Hopefully sh represents an expected unhashed patch, and Hashed hash sh represents an expected hashed patch with its hash.

data PatchInfoAnd p Source

PatchInfoAnd p represents a hope we have to get a patch through its info. We're not sure we have the patch, but we know its info.

piap :: PatchInfo -> Named p -> PatchInfoAnd pSource

piap i p creates a PatchInfoAnd containing p with info i.

n2pia :: Named p -> PatchInfoAnd pSource

n2pia creates a PatchInfoAnd representing a Named patch.

conscientiously :: (Doc -> Doc) -> PatchInfoAnd p -> Named pSource

conscientiously er hp tries to extract a patch from a PatchInfoAnd. If it fails, it applies the error handling function er to a description of the patch info component of hp.

hopefully :: PatchInfoAnd p -> Named pSource

hopefully hp tries to get a patch from a PatchInfoAnd value. If it fails, it outputs an error "failed to read patch: <description of the patch>". We get the description of the patch from the info part of hp

hopefullyM :: Monad m => PatchInfoAnd p -> m (Named p)Source

hopefullyM is a version of hopefully which calls fail in a monad instead of erroring.