Data.Monoid.Nonfree

Documentation

data N a

Nonfree nonmonoid.

Constructors

N a

NEmpty

NAppend (N a) (N a)

Instances

Functor N

Foldable N

Traversable N

Show a => Show (N a)

The Show instance uses short names to make the append trees readable.

Monoid (N a)

(◇) :: Monoid m => m -> m -> m

A synonym for mappend (<>).

ε :: Monoid m => m

A synonym for mempty.

toN :: Foldable t => t a -> N a

A version of toList that extracts the full monoid append tree rather than flattening it to a list.

fromN :: Traversable t => N b -> t a -> t b

Given a monoid append tree and a Traversable structure with exactly the same shape, put values from the former into the latter. This will fail with an error if the structure isn't identical.