Draft a very simple WebAnno reader ignoring the fields described in header and...

Draft a very simple WebAnno reader ignoring the fields described in header and taking a lot from TSV and CoNLL

lib/Text/TEIWA.hs

@@ -8,6 +8,7 @@ module Text.TEIWA (
     , annotateWith
     , fromCSV
     , fromCoNLLX
+    , fromWebAnno
   ) where
 
 import Control.Monad.Except (MonadError(..))
@@ -34,3 +35,6 @@ fromCSV = annotate . Source csv
 
 fromCoNLLX :: (MonadError Error m, MonadIO m) => Origin -> Filter m
 fromCoNLLX = annotate . Source coNLLX
+
+fromWebAnno :: (MonadError Error m, MonadIO m) => Origin -> Filter m
+fromWebAnno = annotate . Source webAnno

lib/Text/TEIWA/Source.hs

@@ -10,8 +10,10 @@ module Text.TEIWA.Source (
     , runTEIWAParser
     , parse
     , tsv
+    , webAnno
   ) where
 
+import Control.Applicative ((<|>))
 import Control.Monad.Except (MonadError(..))
 import Control.Monad.Reader (MonadReader(..), ReaderT(..))
 import Control.Monad.IO.Class (MonadIO(..))
@@ -28,6 +30,7 @@ import Text.TEIWA.Source.Common (
   )
 import qualified Text.TEIWA.Source.CoNLLX as CoNLLX (header, sentences)
 import qualified Text.TEIWA.Source.SSV as SSV (body, header)
+import qualified Text.TEIWA.Source.WebAnno as WebAnno (header, sentences)
 
 type Format = TEIWAParser Annotation
 
@@ -69,7 +72,16 @@ csv :: Format
 csv = ssv ','
 
 tsv :: Format
-tsv = ssv '\t'
+tsv = webAnno <|> ssv '\t'
+
+webAnno :: Format
+webAnno = do
+  context <- annotationContext =<< WebAnno.header
+  SentenceLevel <$> (
+      WebAnno.sentences >>= mapM (
+          fmap SentenceAnnotation . mapM (annotateToken context)
+        )
+    )
 
 data Origin = File FilePath | Text Text
 

lib/Text/TEIWA/Source/WebAnno.hs

+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Text.TEIWA.Source.WebAnno (
+      header
+    , sentences
+  ) where
+
+import Control.Applicative (many)
+import Data.Text.Lazy as Text (pack)
+import Text.Parsec (
+    ParsecT, Stream, char, digit, many1, noneOf, sepBy1, skipMany1, string
+  )
+import Text.TEIWA.Source.Common (
+    Field, Header, Row, TEIWAParser, eol, recordLine
+  )
+
+header :: TEIWAParser Header
+header = do
+  string "#FORMAT=WebAnno TSV " *> version
+  many comment *> pure ()
+  pure [
+      "ID"
+      , "SPAN"
+      , "FORM"
+      , "LABEL"
+    ]
+  where
+    version = skipMany1 digit `sepBy1` char '.' *> eol 
+    comment = char '#' *> many (noneOf "\r\n") <* eol
+
+field :: Stream s m Char => ParsecT s u m Field
+field = build <$> many1 (noneOf "\t\n\r")
+  where
+    build "_" = Nothing
+    build s = Just . Text.pack $ unescape s
+    unescape "" = ""
+    unescape ('\\':c:s) = c:unescape s
+    unescape (c:s) = c:unescape s
+
+row :: Stream s m Char => ParsecT s u m Row
+row = recordLine (many1 (field <* char '\t') <* eol)
+
+type Sentence = [Row]
+
+sentence :: Stream s m Char => ParsecT s u m Sentence
+sentence = many comment *> many1 row
+  where
+    comment = char '#' *> many (noneOf "\r\n") <* eol
+
+sentences :: Stream s m Char => ParsecT s u m [Sentence]
+sentences = many (many1 eol *> sentence)

teiwa.cabal

@@ -31,6 +31,7 @@ library
                      , Text.TEIWA.Source.Common
                      , Text.TEIWA.Source.CoNLLX
                      , Text.TEIWA.Source.SSV
+                     , Text.TEIWA.Source.WebAnno
   build-depends:       base >=4.12 && <4.15
                      , bytestring
                      , mtl