pandoc- Conversion between markup formats

CopyrightCopyright (C) 2010-2014 John MacFarlane
LicenseGNU GPL, version 2 or above
MaintainerJohn MacFarlane <>
Safe HaskellNone



A prettyprinting library for the production of text documents, including wrapped text, indentated blocks, and tables.



data Doc


render :: (Monoid a, IsString a) => Maybe Int -> Doc -> a

Renders a Doc. render (Just n) will use a line length of n to reflow text on breakable spaces. render Nothing will not reflow text.

cr :: Doc

A carriage return. Does nothing if we're at the beginning of a line; otherwise inserts a newline.

blankline :: Doc

Inserts a blank line unless one exists already. (blankline <> blankline has the same effect as blankline. If you want multiple blank lines, use text "\n\n".

space :: Doc

A breaking (reflowable) space.

text :: String -> Doc

A literal string.

char :: Char -> Doc

A character.

prefixed :: String -> Doc -> Doc

Uses the specified string as a prefix for every line of the inside document (except the first, if not at the beginning of the line).

flush :: Doc -> Doc

Makes a Doc flush against the left margin.

nest :: Int -> Doc -> Doc

Indents a Doc by the specified number of spaces.

hang :: Int -> Doc -> Doc -> Doc

A hanging indent. hang ind start doc prints start, then doc, leaving an indent of ind spaces on every line but the first.

beforeNonBlank :: Doc -> Doc

beforeNonBlank d conditionally includes d unless it is followed by blank space.

nowrap :: Doc -> Doc

Makes a Doc non-reflowable.

offset :: Doc -> Int

Returns the width of a Doc.

height :: Doc -> Int

Returns the height of a block or other Doc.

lblock :: Int -> Doc -> Doc

lblock n d is a block of width n characters, with text derived from d and aligned to the left.

cblock :: Int -> Doc -> Doc

Like lblock but aligned centered.

rblock :: Int -> Doc -> Doc

Like lblock but aligned to the right.

(<>) :: Monoid m => m -> m -> m infixr 6

An infix synonym for mappend.


(<+>) :: Doc -> Doc -> Doc infixr 6

Concatenate a list of Docs, putting breakable spaces between them.

($$) :: Doc -> Doc -> Doc infixr 5

a $$ b puts a above b.

($+$) :: Doc -> Doc -> Doc infixr 5

a $$ b puts a above b, with a blank line between.

isEmpty :: Doc -> Bool

True if the document is empty.

empty :: Doc

The empty document.

cat :: [Doc] -> Doc

Concatenate a list of Docs.

hcat :: [Doc] -> Doc

Same as cat.

hsep :: [Doc] -> Doc

Same as cat, but putting breakable spaces between the Docs.

vcat :: [Doc] -> Doc

List version of $$.

vsep :: [Doc] -> Doc

List version of $+$.

nestle :: Doc -> Doc

Removes leading blank lines from a Doc.

chomp :: Doc -> Doc

Chomps trailing blank space off of a Doc.

inside :: Doc -> Doc -> Doc -> Doc

Encloses a Doc inside a start and end Doc.

braces :: Doc -> Doc

Puts a Doc in curly braces.

brackets :: Doc -> Doc

Puts a Doc in square brackets.

parens :: Doc -> Doc

Puts a Doc in parentheses.

quotes :: Doc -> Doc

Wraps a Doc in single quotes.

doubleQuotes :: Doc -> Doc

Wraps a Doc in double quotes.

charWidth :: Char -> Int

Returns width of a character in a monospace font: 0 for a combining character, 1 for a regular character, 2 for an East Asian wide character.

realLength :: String -> Int

Get real length of string, taking into account combining and double-wide characters.