Data.Git.Oid

The Oid type represents a Git hash value, whether partial or full. In general users do not interact with this type much, as all the top-level functions which expect hash values typically expect strings.

Documentation

data Oid

Oid represents either a full or partial SHA1 hash code used to identify Git objects.

Constructors

Oid COid

PartialOid COid Int

Instances

Eq Oid

Show Oid

newtype COid

COid is a type wrapper for a foreign pointer to libgit2's git_oid structure. Users should not have to deal with this type.

Constructors

COid (ForeignPtr C'git_oid)

Instances

Eq COid

Ord COid

Show COid

oidToStr :: Ptr C'git_oid -> IO String

data ObjRef a

ObjRef refers to either a Git object of a particular type (if it has already been loaded into memory), or it refers to the COid of that object in the repository. This permits deferred loading of objects within potentially very large structures, such as trees and commits. However, it also means that every access to a sub-object must use loadObject from the type class Updatable.

Constructors

IdRef COid

ObjRef a

Instances

Show a => Show (ObjRef a)

data Ident a

An Ident abstracts the fact that some objects won't have an identifier until they are written to disk -- even if sufficient information exists to determine that hash value. If construct as a Pending value, it is an IO action that writes the object to disk and retrieves the resulting hash value from Git; if Stored, it is a COid that is known to the repository.

Constructors

Pending (a -> IO COid)

Stored COid

Instances

Show (Ident a)

wrapOidPtr :: Ptr C'git_oid -> IO (ObjRef a)

compareCOid :: COid -> COid -> Ordering

Compare two COid values for equality. More typical is to use compare.

compareCOidLen :: COid -> COid -> Int -> Ordering

Compare two COid values for equality, but only up to a certain length.

equalCOid :: Ord a => a -> a -> Bool

True if two COid values are equal.

stringToOid :: CStringable a => a -> IO (Maybe Oid)

Convert a hash string to a Maybe Oid value. If the string is less than 40 hexadecimal digits, the result will be of type PartialOid.

>>> stringToOid "a143ecf"
Just a143ecf
>>> stringToOid "a143ecf" >>= (\(Just (PartialOid _ l)) -> return $ l == 7)
True

>>> let hash = "6cfc2ca31732fb6fa6b54bae6e586a57a0611aab"
>>> stringToOid hash
Just 6cfc2ca31732fb6fa6b54bae6e586a57a0611aab
>>> stringToOid hash >>= (\(Just (Oid _)) -> return True)
True