-- A helper module to convert XML produced by Erlang's TypEr application
-- to Haskell code to call Erlang functions with proper type annotations.

-- This module implements a Parsec-based parser for XML that was converted
-- by parsing the output from TypEr.
-- First, XML (provided as a string) is processed by TagSoup, resulting in a list of tags
-- as the XML tree is traversed. Next, Parsec-based part converts the list of tags
-- into an internal representation. Finally, Haskell pretty-printer
-- generates Haskell source that contains code to call Erlang functions specified by Edoc.

module Language.Edoc.TyXml2Hs (
  xml2hs) where

import Text.HTML.TagSoup
import Text.HTML.TagSoup.Parser
import Text.ParserCombinators.Parsec
import Language.Haskell.Pretty

import Language.Edoc.Xml2Hs.Type
import Language.Edoc.Xml2Hs.Parser 
import Language.Edoc.Xml2Hs.TyParser
import Language.Edoc.Xml2Hs.Haskell

-- |The main function: takes XML as a string and returns Haskell as a string.
--  Parsing errors will be thrown as exceptions if occur.

xml2hs :: String -> String

xml2hs xml =
  let tags = parseTags xml
      parsed = either (error . show) id $ runParser (pTyMod "ErlImport") PState {counter = 0} "" tags
      hmod = edoc2mod parsed
  in  prettyPrint hmod