commonmark-0.2.4: Pure Haskell commonmark parser.

Safe Haskell | Safe-Inferred
Language | Haskell2010

Commonmark

Description

The basic task of this library is to parse text as commonmark. Usage example:

    {-# LANGUAGE ScopedTypeVariables #-}
    import Commonmark
    import Data.Text.IO as TIO
    import Data.Text.Lazy.IO as TLIO

    main = do
      res <- commonmark "stdin" <$> TIO.getContents
      case res of
        Left e                  -> error (show e)
        Right (html :: Html ()) -> TLIO.putStr $ renderHtml html

The parser is highly polymorphic: in this example, we use the type annotation ``Html` ()` to indicate that we want it to produce basic HTML without source location attributes. And we return a value in the IO monad. But we could have used a different output format (e.g. ``Html` `SourceRange`` for HTML with source location attributes). And we could have used the Identity monad to get a pure value. (The default parsers work the same way in any monad, but it is possible to define extensions that constrain the monad. For example, an extension for include files might only work in IO, or might have different behavior in IO and Identity.)

Extensibility is emphasized throughout. To change the output for a given format, or support an alternate output format, one has only to define instances of `IsBlock` and `IsInline` for a new type. (For an example of this kind of extension, see the `commonmark-pandoc` package, which defines these instances for pandoc's native types.)

Supporting a new syntactic element generally requires (a) adding a `SyntaxSpec` for it and (b) defining new type classes. See the examples in the `commonmark-extensions` package. Note that `SyntaxSpec` is a Monoid, so one can extend `defaultSyntaxSpec` by specifying `myNewSyntaxSpec <> defaultSyntaxSpec`.

# Documentation

module Commonmark.Tokens

module Commonmark.Types

module Commonmark.Syntax

module Commonmark.Parser

module Commonmark.SourceMap

module Commonmark.Html