Data.Functor.Classes

Lifting of the Eq class to unary type constructors.

Any instance should be subject to the following law that canonicity is preserved:

liftEq (==) = (==)

This class therefore represents the generalization of Eq by decomposing its main method into a canonical lifting on a canonical inner method, so that the lifting can be reused for other arguments than the canonical one.

Lift the standard (==) function through the type constructor.

Lifting of the Ord class to unary type constructors.

Any instance should be subject to the following law that canonicity is preserved:

liftCompare compare = compare

This class therefore represents the generalization of Ord by decomposing its main method into a canonical lifting on a canonical inner method, so that the lifting can be reused for other arguments than the canonical one.

Lift the standard compare function through the type constructor.

Lifting of the Read class to unary type constructors.

Any instance should be subject to the following laws that canonicity is preserved:

liftReadsPrec readsPrec readList = readsPrec

liftReadList readsPrec readList = readList

liftReadPrec readPrec readListPrec = readPrec

liftReadListPrec readPrec readListPrec = readListPrec

This class therefore represents the generalization of Read by decomposing it's methods into a canonical lifting on a canonical inner method, so that the lifting can be reused for other arguments than the canonical one.

Both liftReadsPrec and liftReadPrec exist to match the interface provided in the Read type class, but it is recommended to implement Read1 instances using liftReadPrec as opposed to liftReadsPrec, since the former is more efficient than the latter. For example:

instance Read1 T where
  liftReadPrec     = ...
  liftReadListPrec = liftReadListPrecDefault

For more information, refer to the documentation for the Read class.

Lift the standard readsPrec and readList functions through the type constructor.

Lift the standard readPrec and readListPrec functions through the type constructor.

A possible replacement definition for the liftReadList method. This is only needed for Read1 instances where liftReadListPrec isn't defined as liftReadListPrecDefault.

A possible replacement definition for the liftReadListPrec method, defined using liftReadPrec.

Lifting of the Show class to unary type constructors.

Any instance should be subject to the following laws that canonicity is preserved:

liftShowsPrec showsPrec showList = showsPrec

liftShowList showsPrec showList = showList

This class therefore represents the generalization of Show by decomposing it's methods into a canonical lifting on a canonical inner method, so that the lifting can be reused for other arguments than the canonical one.

Lift the standard showsPrec and showList functions through the type constructor.

Lifting of the Eq class to binary type constructors.

Lift the standard (==) function through the type constructor.

Lifting of the Ord class to binary type constructors.

Lift the standard compare function through the type constructor.

Lifting of the Read class to binary type constructors.

Both liftReadsPrec2 and liftReadPrec2 exist to match the interface provided in the Read type class, but it is recommended to implement Read2 instances using liftReadPrec2 as opposed to liftReadsPrec2, since the former is more efficient than the latter. For example:

instance Read2 T where
  liftReadPrec2     = ...
  liftReadListPrec2 = liftReadListPrec2Default

For more information, refer to the documentation for the Read class.

Lift the standard readsPrec function through the type constructor.

Lift the standard readPrec function through the type constructor.

A possible replacement definition for the liftReadList2 method. This is only needed for Read2 instances where liftReadListPrec2 isn't defined as liftReadListPrec2Default.

A possible replacement definition for the liftReadListPrec2 method, defined using liftReadPrec2.

Lifting of the Show class to binary type constructors.

Lift the standard showsPrec function through the type constructor.

readsUnary n c n' matches the name of a unary data constructor and then parses its argument using readsPrec.

readsUnary1 n c n' matches the name of a unary data constructor and then parses its argument using readsPrec1.

readsBinary1 n c n' matches the name of a binary data constructor and then parses its arguments using readsPrec1.

showsUnary n d x produces the string representation of a unary data constructor with name n and argument x, in precedence context d.

showsUnary1 n d x produces the string representation of a unary data constructor with name n and argument x, in precedence context d.

showsBinary1 n d x y produces the string representation of a binary data constructor with name n and arguments x and y, in precedence context d.