Add support for ledger3 style multi-line comments

hledger-lib/Hledger/Read.hs

@@ -204,6 +204,11 @@ samplejournal = readJournal' $ unlines
  ,"    assets:bank:checking  $1"
  ,"    income:salary"
  ,""
+ ,"comment"
+ ,"multi line comment here"
+ ,"for testing purposes"
+ ,"end comment"
+ ,""
  ,"2008/06/01 gift"
  ,"    assets:bank:checking  $1"
  ,"    income:gifts"

hledger-lib/Hledger/Read/JournalReader.hs

@@ -164,6 +164,7 @@ journal = do
                            , liftM (return . addPeriodicTransaction) periodictransaction
                            , liftM (return . addHistoricalPrice) historicalpricedirective
                            , emptyorcommentlinep >> return (return id)
+                           , multilinecommentp >> return (return id)
                            ] <?> "journal transaction or directive"
 
 -- cf http://ledger-cli.org/3.0/doc/ledger3.html#Command-Directives
@@ -847,6 +848,15 @@ test_numberp = do
 
 -- comment parsers
 
+multilinecommentp :: GenParser Char JournalContext ()
+multilinecommentp = do
+  string "comment" >> newline
+  go
+  where
+    go = try (string "end comment" >> newline >> return ())
+         <|> (anyLine >> go)
+    anyLine = anyChar `manyTill` newline
+
 emptyorcommentlinep :: GenParser Char JournalContext ()
 emptyorcommentlinep = do
   many spacenonewline >> (comment <|> (many spacenonewline >> newline >> return ""))