Text.Pandoc.JSON

pandoc-types-1.23: Types for representing a structured document

Copyright | Copyright (C) 2013-2023 John MacFarlane
License | BSD3
Maintainer | John MacFarlane <jgm@berkeley.edu>
Stability | alpha
Portability | portable
Safe Haskell | Safe-Inferred
Language | Haskell2010

Text.Pandoc.JSON

Description

Functions for serializing the Pandoc AST to JSON and deserializing from JSON.

Example of use: The following script (`capitalize.hs`) reads reads a JSON representation of a Pandoc document from stdin, and writes a JSON representation of a Pandoc document to stdout. It changes all regular text in the document to uppercase, without affecting URLs, code, tags, etc. Run the script with

    pandoc -t json | runghc capitalize.hs | pandoc -f json

or (making capitalize.hs executable)

    pandoc --filter ./capitalize.hs

    #!/usr/bin/env runghc
    import Text.Pandoc.JSON
    import Data.Char (toUpper)

    main :: IO ()
    main = toJSONFilter capitalizeStrings

    capitalizeStrings :: Inline -> Inline
    capitalizeStrings (Str s) = Str $ map toUpper s
    capitalizeStrings x       = x

Synopsis

- module Text.Pandoc.Definition
- class ToJSONFilter m a where
  - toJSONFilter :: a -> m ()

# Documentation

module Text.Pandoc.Definition

class ToJSONFilter m a where #

`toJSONFilter` convert a function into a filter that reads pandoc's JSON serialized output from stdin, transforms it by walking the AST and applying the specified function, and serializes the result as JSON to stdout.

For a straight transformation, use a function of type `a -> a` or `a -> IO a` where `a` = `Block`, `Inline`, `Pandoc`, `Meta`, or `MetaValue`.

If your transformation needs to be sensitive to the script's arguments, use a function of type `[String] -> a -> a` (with `a` constrained as above). The `[String]` will be populated with the script's arguments.

An alternative is to use the type `Maybe Format -> a -> a`. This is appropriate when the first argument of the script (if present) will be the target format, and allows scripts to behave differently depending on the target format. The pandoc executable automatically provides the target format as argument when scripts are called using the `--filter` option.

Methods

toJSONFilter :: a -> m () #

#### Instances

Instances details

Walkable a Pandoc => ToJSONFilter IO (a -> a) # |
Instance details Defined in Text.Pandoc.JSON Methods toJSONFilter :: (a -> a) -> IO () #
(ToJSONFilter m a, MonadIO m) => ToJSONFilter m (Maybe Format -> a) # |
Instance details Defined in Text.Pandoc.JSON Methods toJSONFilter :: (Maybe Format -> a) -> m () #
(ToJSONFilter m a, MonadIO m) => ToJSONFilter m ([String] -> a) # |
Instance details Defined in Text.Pandoc.JSON Methods toJSONFilter :: ([String] -> a) -> m () #
(Walkable [a] Pandoc, MonadIO m) => ToJSONFilter m (a -> m [a]) # |
Instance details Defined in Text.Pandoc.JSON Methods toJSONFilter :: (a -> m [a]) -> m () #
(Walkable a Pandoc, MonadIO m) => ToJSONFilter m (a -> m a) # |
Instance details Defined in Text.Pandoc.JSON Methods toJSONFilter :: (a -> m a) -> m () #