rollback and until

src/GenericParser.purs

@@ -6,4 +6,4 @@ module GenericParser
 
 import GenericParser.DomainParser.Common (DomainError(..), ldh_str, let_dig, let_dig_hyp, max_domain_length, max_label_length, Size)
 import GenericParser.DomainParser (domain, label, subdomain, sub_eof)
-import GenericParser.Parser (alphanum, char, current_input, current_position, digit, eof, Error, failure, failureError, ident, identifier, Input, int, integer, item, letter, lower, many1, nat, natural, parse, parse_last_char, Parser(..), Position, PositionString, Result, sat, space, string, success, symbol, token, try, tryMaybe, upper, Value)
+import GenericParser.Parser (alphanum, char, current_input, current_position, digit, eof, Error, failure, failureError, ident, identifier, Input, int, integer, item, letter, lower, many1, nat, natural, parse, parse_last_char, Parser(..), Position, PositionString, Result, rollback, sat, space, string, success, symbol, token, try, tryMaybe, until, upper, Value)

src/GenericParser/DomainParser.purs

@@ -6,8 +6,6 @@ import Prelude (bind, not, pure, ($), (&&), (*>), (<<<), (<>), (>), (-))
 
 import Control.Alt ((<|>))
 import Control.Lazy (defer)
-import Data.Array as A
-import Data.Either (Either(..))
 import Data.Maybe (Maybe(..), maybe)
 import Data.String as S
 import Data.String.CodeUnits as CU

src/GenericParser/EmailAddress.purs

@@ -31,7 +31,7 @@ email :: Parser EmailError String
 email = do login <- login_part
            _ <- char '@'
            input <- current_input
-           case parse sub_eof { string: input.string, position: input.position } of
+           case parse sub_eof input of
              Left {error, position} ->
                Parser \_ -> failureError position (Just $ InvalidDomain error)
              Right {result} -> pure $ login <> "@" <> result

src/GenericParser/Parser.purs

@@ -3,12 +3,12 @@ import Prelude
 
 import Control.Alt (class Alt, (<|>))
 import Control.Alternative (class Alternative)
-import Control.Lazy (class Lazy)
+import Control.Lazy (class Lazy, defer)
 import Control.Plus (class Plus, empty)
 import Data.Array as A
 import Data.Either (Either(..))
 import Data.Int as Int
-import Data.Maybe (Maybe(..))
+import Data.Maybe (Maybe(..), maybe)
 import Data.String as S
 import Data.String.CodeUnits (toCharArray, fromCharArray, singleton)
 
@@ -42,6 +42,12 @@ current_position = Parser \input -> success input input.position
 current_input :: forall e. Parser e Input
 current_input = Parser \input -> success input input
 
+-- | `rollback` replaces the current input.
+-- |
+-- | This function cannot fail since no parsing is performed.
+rollback :: forall e. Input -> Parser e Unit
+rollback newinput = Parser \_ -> success newinput unit
+
 -- | Fail with a specified error.
 -- | When a parsing has a specified error, no alternative will be tried and the error is reported.
 failureError :: forall e v. Position -> Maybe e -> Result e v
@@ -212,6 +218,17 @@ many1 p = do first <- p
              rest <- A.many p
              pure $ A.cons first rest
 
+-- | TODO: `until`
+until :: forall e v. Parser e v -> Parser e v -> Parser e (Array v)
+until parser_end p = do
+  input <- current_input
+  case parse parser_end input of
+    Left _  -> do v <- p
+                  mayberest <- tryMaybe $ defer \_ -> until parser_end p
+                  pure $ [v] <> maybe [] id mayberest
+    Right _ -> Parser \_ -> failure input.position
+  where id x = x
+
 -- | Parse the last character of a String.
 -- | Return false in case the string is empty.
 parse_last_char :: forall e. String -> Parser e Char -> Boolean