Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Fmt.Functor

Contents

Description

Pattern functor for document trees.

Doc m ann is the base functor for pretty-printer documents, parametric over content type m and annotation type ann.

Changes from prettyprinter's DocF:

Synopsis

Pattern functor

data Doc m ann r Source #

One layer of a document tree.

r marks recursive positions. m is the content type (e.g. Text, Builder). ann is the annotation type (e.g. ANSI styles, HTML tags).

Constructors

Fail	Layout failure. Produced by `flatten` on hard line breaks; consumed by the layout algorithm to reject a flattened branch.
Empty	Empty document.
Leaf !Int !m	Literal content with cached display width.
Cat r r	Concatenation.
Line	Hard line break. Cannot be flattened (becomes `Fail`).
FlatAlt r r	`FlatAlt default flat`: use `default` normally, `flat` when flattened by `group`.
Nest !Int r	`Nest i doc`: increase nesting by `i` for `doc`.
Union r r	`Union wide narrow`: layout alternatives. Invariant: `wide` is the flattened form of `narrow`. Internal — constructed only by `group`.
Ann ann r	Annotated document.
Column (Int -> r)	React to the current column position.
Nesting (Int -> r)	React to the current nesting level.

Instances details

IsString m => IsString (Tree m ann) Source #
Instance details Defined in Data.Fmt.Functor Methods fromString :: String -> Tree m ann #
Functor (Doc m ann) Source #
Instance details Defined in Data.Fmt.Functor Methods fmap :: (a -> b) -> Doc m ann a -> Doc m ann b # (<$) :: a -> Doc m ann b -> Doc m ann a #
Monoid (Tree m ann) Source #
Instance details Defined in Data.Fmt.Functor Methods mempty :: Tree m ann # mappend :: Tree m ann -> Tree m ann -> Tree m ann # mconcat :: [Tree m ann] -> Tree m ann #
Semigroup (Tree m ann) Source #
Instance details Defined in Data.Fmt.Functor Methods (<>) :: Tree m ann -> Tree m ann -> Tree m ann # sconcat :: NonEmpty (Tree m ann) -> Tree m ann # stimes :: Integral b => b -> Tree m ann -> Tree m ann #

Tree

type Tree m ann = Mu (Doc m ann) Source #

A document tree: the initial algebra of Doc m ann.