Safe Haskell	None
Language	Haskell2010

Darcs.Util.Printer

Description

A Document is at heart ShowS from the prelude

Essentially, if you give a Doc a string it'll print out whatever it wants followed by that string. So text "foo" makes the Doc that prints "foo" followed by its argument. The combinator names are taken from HughesPJ, although the behaviour of the two libraries is slightly different.

The advantage of Printer over simple string appending/concatenating is that the appends end up associating to the right, e.g.:

  (text "foo" <> text "bar") <> (text "baz" <> text "quux") ""
= \s -> (text "foo" <> text "bar") ((text "baz" <> text "quux") s) ""
= (text "foo" <> text "bar") ((text "baz" <> text "quux") "")
= (\s -> (text "foo") (text "bar" s)) ((text "baz" <> text "quux") "")
= text "foo" (text "bar" ((text "baz" <> text "quux") ""))
= (\s -> "foo" ++ s) (text "bar" ((text "baz" <> text "quux") ""))
= "foo" ++ (text "bar" ((text "baz" <> text "quux") ""))
= "foo" ++ ("bar" ++ ((text "baz" <> text "quux") ""))
= "foo" ++ ("bar" ++ ((\s -> text "baz" (text "quux" s)) ""))
= "foo" ++ ("bar" ++ (text "baz" (text "quux" "")))
= "foo" ++ ("bar" ++ ("baz" ++ (text "quux" "")))
= "foo" ++ ("bar" ++ ("baz" ++ ("quux" ++ "")))

The Empty alternative comes in because you want

text "a" $$ vcat xs $$ text "b"

$$ means above, vcat is the list version of $$ (to be "a\nb" when xs is []), but without the concept of an Empty Document each $$ would add a '\n' and you'd end up with "a\n\nb". Note that Empty /= text "" (the latter would cause two '\\n').

This code was made generic in the element type by Juliusz Chroboczek.

Synopsis

Documentation

data Printable Source

A Printable is either a String, a packed string, or a chunk of text with both representations.

Constructors

S !String
PS !ByteString
Both !String !ByteString

newtype Doc Source

a Doc is a bit of enriched text. Docs get concatanated using <>, which is right-associative.

Constructors

Doc
Fields unDoc :: St -> Document

Instances

IsString Doc

type Printers = Handle -> Printers' Source

data Printers' Source

A set of printers to print different types of text to a handle.

Constructors

Printers
Fields colorP :: !(Color -> Printer) invisibleP :: !Printer hiddenP :: !Printer userchunkP :: !Printer defP :: !Printer lineColorT :: !(Color -> Doc -> Doc) lineColorS :: !([Printable] -> [Printable])

type Printer = Printable -> St -> Document Source

data Color Source

Constructors

Blue
Red
Green
Cyan
Magenta

data RenderMode Source

Used when rendering a Doc to indicate if the result should be encoded to the current locale or left alone. In practice this only affects output when a relevant DARCS_DONT_ESCAPE_XXX option is set (see Darcs.Util.Printer.Color) If in doubt, choose Standard.

Constructors

Encode	Encode Strings with the current locale. At present ByteStrings are assumed to be in UTF8 and are left alone, so will be mis-encoded in non-UTF8 locales.
Standard	Don't encode.

hPutDoc :: RenderMode -> Handle -> Doc -> IO () Source

hputDoc puts a doc on the given handle using simplePrinters

hPutDocLn :: RenderMode -> Handle -> Doc -> IO () Source

putDoc :: Doc -> IO () Source

putDoc puts a doc on stdout using the simple printer simplePrinters.

putDocLn :: Doc -> IO () Source

putDocLn puts a doc, followed by a newline on stdout using simplePrinters

hPutDocWith :: Printers -> RenderMode -> Handle -> Doc -> IO () Source

hputDocWith puts a doc on the given handle using the given printer.

hPutDocLnWith :: Printers -> RenderMode -> Handle -> Doc -> IO () Source

hputDocLnWith puts a doc, followed by a newline on the given handle using the given printer.

putDocWith :: Printers -> Doc -> IO () Source

putDocWith puts a doc on stdout using the given printer.

putDocLnWith :: Printers -> Doc -> IO () Source

putDocLnWith puts a doc, followed by a newline on stdout using the given printer.

hPutDocCompr :: RenderMode -> Handle -> Doc -> IO () Source

like hPutDoc but with compress data before writing

renderString :: RenderMode -> Doc -> String Source

renders a Doc into a String with control codes for the special features of the doc.

renderStringWith :: Printers' -> RenderMode -> Doc -> String Source

renders a Doc into a String using a given set of printers.

renderPS :: RenderMode -> Doc -> ByteString Source

renders a Doc into ByteString with control codes for the special features of the Doc. See also readerString.

renderPSWith :: Printers' -> RenderMode -> Doc -> ByteString Source

renders a doc into a ByteString using a given set of printers.

renderPSs :: RenderMode -> Doc -> [ByteString] Source

renders a Doc into a list of PackedStrings, one for each line.

renderPSsWith :: Printers' -> RenderMode -> Doc -> [ByteString] Source

renders a Doc into a list of PackedStrings, one for each chunk of text that was added to the doc, using the given set of printers.

lineColor :: Color -> Doc -> Doc Source

prefix :: String -> Doc -> Doc Source

insertBeforeLastline :: Doc -> Doc -> Doc Source

colorText :: Color -> String -> Doc Source

colorText creates a Doc containing colored text from a String

invisibleText :: String -> Doc Source

invisibleText creates a Doc containing invisible text from a String

prefixLines :: Doc -> Doc -> Doc Source

hiddenText :: String -> Doc Source

hiddenText creates a Doc containing hidden text from a String

hiddenPrefix :: String -> Doc -> Doc Source

userchunk :: String -> Doc Source

userchunk creates a Doc containing a user chunk from a String

text :: String -> Doc Source

text creates a Doc from a String, using printable.

printable :: Printable -> Doc Source

'printable x' creates a Doc from any Printable.

wrapText :: Int -> String -> Doc Source

wrapText n s is a Doc representing s line-wrapped at n characters

blueText :: String -> Doc Source